Reportstack has announced a new report on The Global Military GPS/GNSS Market 2013-2023. This report offers the reader detailed analysis of the global military GPS/GNSS market over the next 10 years, alongside potential market opportunities to enter the industry, using detailed market size forecasts, Reportstack said.
A satellite navigation system provides GPS positioning from a global perspective, and is therefore of utmost importance for modern-day military operations, which rely on accurate real-time data on hostile forces in order to carry out precision attacks, Reportstack said. It is here that GPS/GNSS devices assume an important role, as they are imperative to transfer signals from these satellites back to earth.
The U.S. is the highest spender on military GPS/GNSS navigation, and is responsible for 42.9% of the global military GNSS devices market. Others major spenders in this sector include Russia, the UK, China and India. In July 2013, India launched the IRNSS-1A, the first of seven satellite constellation to be deployed under the Indian Regional Navigation Satellite System (IRNSS) program to be completed between 2015-2016. And China’s BeiDou is scheduled to be operational by 2020.
Another factor driving the market is the integration of satellite navigation technology with other navigation systems, such as the inertial navigation system (INS) and gyro, as GPS devices are to be used in order to decipher data correctly, Reportstack said.
The increasing demand for satellite navigation and communications is driven primarily by the desire of militaries to monitor more areas and derive accurate information by a range of GNSS receivers/sensors in the shortest time possible. Major military aircraft and helicopters are dependent on GPS embedded INS systems for effective navigation. Similarly, naval vessels and guided munitions are increasingly relying on the collaboration of laser, gyro, INS, and satellite navigation technologies to derive accurate real time data.
Furthermore, it has been observed that the usage of standard positioning services/open service receivers, which use unencrypted signal for non-combat purposes has increased, and is expected to drive demand and encourage expenditure, Reportstack said. The military GPS/GNSS technology is expanding its horizon beyond the basic characteristics of navigation and tracking. The use of GPS, in conjunction with a number of software applications, has expanded its use in military operations. A number of new technologies are now embedded with GPS receivers to produce a more sophisticated military tool.
Recently, a Swiss-based company developed a device called GPS Log Book based on u-blox technology. The new device has extended the scope of GPS technology to the administrative side of military operations. It provides an easy way for military drivers to automatically keep an accurate travel log book which can be securely accessed later from anywhere via a web interface. Information logged includes route, speed, and distance traveled. It also keeps a close record of fuel used by the vehicle, based on the distance traveled at various speed levels.
The advent of Differential GPS (DGPS), an enhancement to GPS, which provides improved location accuracy, from the 15-meter nominal GPS accuracy to approximately 10 cm, has further expanded the scope of GPS in missile technology. The intercontinental ballistic missiles, which are capable of hitting targets across thousands of miles navigation, use inertial navigation with DGPS receivers. The advent of DGPS is expected to be one of the most significant steps in accurate missile targeting for militaries across regions.
The companies mentioned in this report are Northrop Grumman, Raytheon, Rockwell Collins , Lockheed Martin, ITT Exelis, Thales, and BAE Systems. More details and table of contents about this report can be found by visiting The Global Military GPS/GNSS Market 2013-2023 report.
PCTEL, Inc. will display its GPS, GNSS, mobile, and infrastructure communication antennas at the 2013 MILCOM Military Communications Conference. MILCOM is being held in the San Diego Convention Center, San Diego, California, November 18-20.
PCTEL Connected Solutions provides advanced military antenna designs. Its high-precision, ruggedized antennas enable reliable communications, timing, and location services in the field, while its site solutions products aid deployments of communications equipment for outdoor and indoor applications, the company said.
PCTEL’s precision GPS and GNSS antennas are used for munitions guidance, aviation, marine, tactical radio manpack, vehicle tracking, soldier, and asset tracking. Recently, PCTEL expanded its GNSS antenna line to include the GPS-LB12GL-MAG, a multiband GPS L1/2, L-Band, and GLONASS antenna. At MILCOM, PCTEL will be showcasing the GPS-L1L2-28MAG, a GPS L1/L2 antenna that has been approved for DAGR (Defense Advanced GPS Receiver) applications. Both of these antennas can be used as soldier-worn asset trackers, military vehicle trackers, and other military tracking applications.
Reliable communications are critical to any field operation. PCTEL’s ruggedized, high performance antennas have been deployed and qualified for tactical mesh networking, which enables complex field communications. PCTEL designs both SISO and MIMO antennas that cover the NATO IV band, also known as the 4.4 GHz C band. For mesh networking and many other mission critical communications systems, accurate GPS timing information is essential. PCTEL has designed the GPS-TMG-HR-26N GPS timing antenna with high out-of-band rejection for reliable communications in high-interference environments.
In addition to its high-performance antennas, PCTEL provides site solutions that enable indoor and outdoor deployments of communications systems for public safety and defense applications, including enclosure systems, coaxial cable assemblies, fiber jumpers, lightning protection, and mobile towers.
“PCTEL designs products that users can count on to help deliver wireless solutions when it matters–and no situation matters more than military field operations,” said Jeff Miller, president of PCTEL Connected Solutions. “We continue to work closely with our customers to expand our portfolio of GPS, GNSS, and communications antennas and site solutions that address emerging needs,” added Miller.
Northrop Grumman Corporation has developed and demonstrated a new micro-Nuclear Magnetic Resonance Gyro (micro-NMRG) prototype for the Defense Advanced Research Projects Agency (DARPA), providing precision navigation for size- and power-constrained applications.
The development of a hermetically sealed micro-NMRG that meets precision navigation requirements along with a successful prototype demonstration marks the fourth and final phase of DARPA’s Navigation-Grade Integrated Micro Gyroscopes (NGIMG) program. The culmination of the eight-year program is a micro-NMRG that offers near navigation-grade performance for the next generation of high-precision inertial sensors.
Northrop Grumman’s micro-NMRG technology uses the spin of atomic nuclei to detect and measure rotation, providing comparable performance to a navigation-grade fiber-optic gyro in a small, lightweight, low-power package. Additionally, the gyro has no moving parts and is not inherently sensitive to vibration and acceleration. The technology can be used in any application requiring small size and low power precision navigation, including personal and unmanned vehicle navigation in GPS-denied or GPS-challenged locations.
“Our miniature gyro technology offers unprecedented size, weight and power savings in a compact package, exceeding program requirements,” said Charles Volk, vice president of Northrop Grumman’s Advanced Navigation Systems business unit. “This important technology can help protect our warfighters by offering highly accurate positioning information, regardless of GPS availability.”
The NGIMG effort is part of DARPA’s Micro-Technology for Positioning, Navigation and Timing program that aims to develop technology for self-contained, chip-scale inertial navigation and precision guidance. Northrop Grumman began the first phase of the NGIMG effort in October 2005 and has consistently met or exceeded the performance goals of each program phase.
GPS Source has received an indefinite-delivery/indefinite-quantity, firm-fixed-price contract with a maximum value of $16,613,430 for the procurement of defense advanced global positioning system receiver distributed devices (D3). The Army Contracting Command, Aberdeen Proving Ground, Md., was the contracting activity (W15P7T-13-D-C116).
GLI-FLO was developed by the defense contract engineering firm, GPS Source. GLI-FLO is a DAGR Distributed Device (D3) that can replace the position, navigation and timing (PNT) role currently required of the DAGR or other GB-GRAM devices inside a fixed vehicle platform. Designed as a single, secure access point to multiple devices requiring PNT data on a fixed vehicle platform, it saves space, weight and power (SWaP).
“The GLI-FLO contract award is an important milestone in GPS Source’s initiative for the defense market,” said Robert Horton, CEO of GPS Source. “Getting this award was a complicated process, but it helps fulfill our vision of continual innovation in GNSS Signal Availability, especially for the warfighter. We look forward to continuing to provide manufacturing and engineering support services to the Department of Defense.”
Abstract submissions are now being accepted for the Institute of Navigation (ION) 2014 Joint Navigation Conference (JNC) to be held June 16-19, 2014.
For Official Use Only (FOUO) U.S.-only sessions will be held June 16-18 at the Renaissance Orlando at SeaWorld, Orlando, Florida; and the 4-EYES CLASSIFIED sessions will be held June 19 at Shades of Green Walt Disney World.
The conference, sponsored by the ION’s Military Division, is the largest U.S. military positioning, navigation and timing conference of the year with joint service and government participation. The event will focus on technical advances in guidance, navigation, and control (GN&C) with emphasis on joint development, test and support of affordable GN&C systems, logistics and integration.
The 2013 Joint Navigation Conference was canceled, so this will be the first time the conference has been held in two years.
From an operational perspective, the conference will also focus on advances in battlefield applications of GPS; critical strengths or weaknesses of fielded navigation devices; warfighter PNT requirements and solutions; and navigation warfare.
The ION JNC features more than 200 operational presentations on a diverse array of topics including:
Advanced Security Technologies/SAASM
Alternate Navigation Technologies: I, II & III
Atomic Clocks and Timing Applications
Autonomous Navigation
Aviation Applications
Battlefield Smart Phone Applications
Celestial Navigation and Star-Tracker Technology
Collaborative Navigation Techniques
GPS Constellation Performance
GPS in Military Applications/NAVWAR
GPS Modernization
Land Applications
Marine Applications
MEMS Inertial Measurement Unit
Micro Navigation Applications
Military GPS Receivers and Military GPS Receiver Technology
Military GPS Use and Experiences
Military GPS/Antenna Technologies and Interference Mitigation
Missile Applications
Modeling and Simulation
Multi-GNSS Receivers for Military Applications
Multi-Sensor Solutions for Guidance, Navigation, and Control
Navigating in Challenged Environments (e.g. Urban, Indoor and
Sub-Surface Navigation)
Precision Azimuth Sensing
Precision Navigation Capabilities for Test and Training
Technical Exhibit and Operational Product Demonstrations. JNC also features a technical exhibit and showcase of Guidance, Navigation and Control technology products and services and Operational Product Demonstrations. For more information on exhibiting and product demonstrations at the ION Joint Navigation Conference, call ION at 703-366-2723 or go to www.ion.org/jnc.
Attendance Restricted. FOUO U.S. ONLY. JNC conference attendance (June 16-19) will be controlled by the Joint Navigation Warfare Center and will be restricted to U.S. ONLY. The classified sessions will have 4-Eyes access (June 19) for citizens of U.S.A., Australia, Canada, and the United Kingdom. All participants must establish a need to know and be approved by the Joint Navigation Warfare Center security office.
GPS Source announced today that GLI-FLO has been granted security approval by the U.S. Air Force Global Positioning Systems Directorate. The GPS Directorate security approval provides GPS Source with the opportunity to supply military end-users and prime contractors with a DAGR Distributed Device (D3) that meets the mandate for reliability and security, GPS Source said.
GLI-FLO is a secure (ICD-GPS-153 compliant) GPS position, navigation, and timing (PNT) distribution device. One GLI-FLO has the same capability as four DAGRs operating in a platform mounted application (eight DAGRs with custom cabling). GLI-FLO serves ICD-GPS-153 PNT data simultaneously to multiple communication or weapon systems that require GPS information. It routes PNT data while secured in the bracket now used by the DAGR, utilizing standard DAGR accessory cables. When GLI-FLO is connected to one DAGR (or as alternative option, interfaces with an internal secure GPS receiver), secure PNT data can be distributed without the integration of GB-GRAM cards to multiple devices.
GLI-FLO meets the stringent requirements for reliability and security by integrating a GPS Directorate-approved SAASM receiver (Selective Availability/Anti-Spoofing Module). SAASM is the security architecture selected by the Joint Chiefs of Staff (JCS) to provide current security functions for GPS-authorized military users.
“We understand the importance of reliable GPS/PNT data for synchronizing military operations and the need to protect against jamming and/or spoofing,” said Robert Horton, CEO of GPS Source. “We further realize the importance of protecting our national assets by designing products that fully comply with all GPS Directorate security requirements. This security approval makes it possible for our GLI-FLO to be deployed by military forces without reservation.”
In addition to the SAASM compliance, other GLI-FLO features include the ability to serve ICD-GPS-153 PNT data simultaneously to multiple communications or weapon systems that require secure GPS information. It is a significant step for GPS Source toward compliance in GPS Signal Distribution (Single PNT Distribution Point). With zero impact to subscriber application software/hardware, it removes the need to rely on multiple, expensive GB-GRAMS found in military platforms.
When a team of firefighters, first responders, or soldiers operates inside a building, in urban canyons, underground, in foliage, or under the forest canopy, the GPS-denied environment presents unique navigation challenges. An enhanced personal inertial navigation system (ePINS), based on a strapdown navigation solution using a mid-grade IMU and wavelet-based motion-classification algorithms, can track positions with errors of less than 2 percent of distance traveled in both indoor and outdoor environments.
By Yunqian Ma, Wayne Soehren, Wes Hawkinson, and Justin Syrstad
Numerous pedestrian navigation applications are currently available or proposed for development. Some of them include localization for coordinating firefighters, first responders, or soldiers. In these applications, the safety and efficiency of the entire team relies directly on the location and orientation of each team member. Operations in high signal interference areas such as cities, rugged terrain, forest, or indoor spaces deliver intermittent or no GPS signal. An alternative to GPS-based location is required.
In this article, we introduce an enhanced personal inertial navigation system (ePINS) solution specifically designed for environments where GPS is unavailable. ePINS combines an array of state-of-the-art sensors and fusion algorithms into a personal navigation system that provides accurate location information for pedestrian applications.
The ePINS concept.
The ePINS solution has the following benefits:
Accurate positioning in GPS-denied environments;
Small, lightweight unit can be easily carried by first responders, rescue workers, or soldiers;
Ruggedized packaging to withstand difficult first responder and military environments.
Features of the ePINS unit include:
State-of-the-art micro-electromechanical systems (MEMS) gyros and accelerometers, barometric altitude sensor, and advanced navigation software;
Advanced motion classification algorithms that accurately identify and measure user activity;
Immunity to magnetic disturbances.
Related Work
In the field of personal navigation, it is common to find systems that rely on sensors that need infrastructure (for example, Wi-Fi positioning) or sensors that actively emit electro-magnetic radiation (such as Doppler radar). These requirements are major drawbacks for communities such as dismounted soldiers in hostile environments.
Other approaches exploit the so-called Zero-velocity update (ZUPT) mechanism, which resets the inertial measurement unit (IMU) velocity errors during the stationary phase of motion. However, implementation of such schemes relies on sensors embedded in footwear, which is not readily accepted in many user communities.
To address these drawbacks, Honeywell has been developing advanced aiding techniques for personal navigation that do not rely on infrastructure and compute a self-contained, relative-navigation solution based only on passive sensors. One technique that Honeywell has developed uses displacement estimation from human-motion models. This technology has been implemented in the ePINS prototype and shows promising performance.
The human-motion model uses IMU measurements as inputs and was developed to infer distance traveled. It generates a displacement estimate that is used as a measurement in the navigation filtering process. The first version of this model was matured under the DARPA individual Precision Inertial Navigation System (iPINS) program. The iPINS system used an IMU, GPS, barometer, and motion classification to estimate a person’s position in both indoor and outdoor environments. In this system, IMU signal characteristics (e.g., peaks and valleys in the accelerations induced by walking) were exploited to differentiate between walking and running. Honeywell recently expanded the human-motion model to identify more specific motion types using a new wavelet motion classification method.
System Description
Figure 1 displays the hardware architecture of the ePINS, a small battery-powered, highly integrated electronic system. The ePINS processing platform is an ARM11-based, i.MX31 system-on-module, paired with support electronics. In addition to the processing platform, the ePINS assembly includes a MEMS IMU, a barometric pressure sensor, a digital magnetometer, and a GPS receiver.
Figure 1. ePINS hardware architecture.
The MEMS IMU provides inertial measurements for strapdown navigation. The IMU’s small package size, light weight, low power consumption, and impressive performance make it attractive for use in the ePINS system. The device is less than 5 cubic inches and weighs less than 0.35 pounds. It consumes about 3 watts of power with a typical current draw of 600mA at 5V.
The ePINS software system is shown in Figure 2. The navigation software runs within Honeywell’s Embedded Computing Toolbox and Operating System (ECTOS IIc), which provides a layered, customizable, and reusable software architecture for implementing navigation, guidance, and control software. A Honeywell-developed simulation tool for offline analysis and development of ECTOS-based software was also used in ePINS development and testing.
The ePINS demonstration device can achieve path performance of less 2 percent distance traveled for walking motion after 1 hour of operation, independent of the magnetic environment. Current performance, packaging characteristics, and interfaces are summarized in Table 1.
Table 1. ePINS performance objectives and physical specifications.
Algorithm Description
Figure 3 depicts the overall sensor integration and data processing scheme used in the ePINS device.
Figure 3. Sensor integration using the ECTOS extended Kalman filter.
Extended Kalman Filter (EKF). The EKF estimates the navigation and sensor errors and computes the resets applied to the strapdown navigation solution to increase its accuracy. Error models for the navigation sensors (IMU, barometric altimeter, magnetometer, GPS, and motion classification) are contained in the EKF. For the ePINS device, the virtual measurements from the step-length model and the strapdown navigation solution are fused by the EKF to assist in bounding the time dependent error growth of the strapdown navigator, which in turn helps maintain calibration of the inertial sensors. A key output of the EKF is the navigation confidence, which is an estimate of the accuracy of the navigation solution.
An important aspect of the EKF and step-length modeling is the residual test that the EKF supports. This test provides a reasonableness comparison between the step-length model estimate and the distance predicted by the strapdown navigation system. This capability significantly increases the robustness of the navigation solution, especially when the user is engaged in motions not recognized during motion classification.
Human-Motion Model. The human-motion model includes two components: wavelet motion classification and step-length model estimation. The wavelet motion classification identifies the type of motion the user is performing, and the step-length model acts as a virtual sensor that quantifies the motion as a distance-traveled estimate.
Wavelet Motion Classification. Human motions are very diverse and highly irregular. Determining what motion is being performed is a challenging problem of classification. Honeywell’s solution is based on wavelet transformation of IMU data. Predefined, or known, characteristics of a variety of motions (such as walking, running, crawling, etc.) are cataloged and stored to a device’s memory. Estimates of those same characteristics for a user are then computed in real time and compared to the catalog of stored information to find the best match.
Generating the catalog of stored information is an offline task that begins by “segmenting” recorded IMU time domain data into individual steps. An example of the output of the segmentation process is shown in Figure 4.
Figure 4. Segmentation of the IMU data using the y-axis accelerometer signal.
Figure 5 displays the segmentation results for two different walking styles (in red and blue) across approximately 15 example steps. As is evident from the graph, walking has characteristics that are common across users, for example, the sharp peaks in the z-axis acceleration caused by foot-ground impacts. Once the data has been segmented, a wavelet transformation on each data channel is performed. Wavelet transformation for many users over many different motion types takes place offline. Subsequently, a wavelet descriptor is built for each motion type based on the transformations into the wavelet domain. With this method, a wide variety of information (that is, descriptors) suitable for input to a classifier is captured about each motion. These descriptors are then cataloged and stored in memory on the ePINS device.
Figure 5. Sample steps for two subjects (red) and (blue).
Finally, for the online phase, the wavelet descriptor of the incoming IMU data is calculated by performing a wavelet transformation on each data channel. This descriptor is then compared to the pre-computed and stored descriptors to classify the motion. FIGURE 7 shows an example of the motion classifier output, where a running motion was used as an input. The classifier successfully determined the motion type (blue field), frequency and phase of the input motion, depicted by the tallest rectangle in the figure.
Figure 7. Classification results from a query of running at a certain frequency and phase (depicted by the dark sphere).
Step-Length Modeling. Once the current motion is identified, a step-length model specific to that motion is used to aid the navigation algorithms. The model for each motion type is obtained by first collecting data that measures step length and step frequency. From this data, the step-length models can be computed by performing a regression analysis of the step-length vs. step-frequency data. Since the step-length models act as a virtual sensor, the models must be as accurate as possible to achieve better system performance. To attain model accuracy, an accurate data collection method is needed.
For ePINS development, step-length models for multiple users have been identified from step-length and timing information using a precise GPS truth reference system. Step-length regression calculations then determine the step length as a function of step frequency (that is, inverse of the step time period). An example of GPS truth data and the corresponding regression model are shown in FIGURE 6 for walking motions.
Figure 6. Step length versus frequency for the walking of subject.
Although basic step-length models are created offline, online calibration of the step-length model can be performed by the EKF if GPS is available during operation. Online calibration tends to increase the overall position accuracy, as variations in the step-length models are likely due to slight variations in biometric differences across humans, terrain features, and even mission plans and duration.
Heading Determination. Heading initialization is one of the key concerns during system start up. In its current operational use, the ePINS device may perform a dynamic or a static initialization of heading. The static method requires the user to survey the system’s initial heading to an accuracy value that is usually specified by mission performance objectives; the absolute position accuracy is dependent upon the accuracy of the initial heading.
The dynamic method is a general method for heading initialization; it is performed without input from the user, but is possible only when GPS is available. This method of heading initialization does not use any a priori information about heading and requires an EKF implementation with a large-azimuth error model. This method requires an additional period of time in which the heading error uncertainty converges.
User Interface. During a mission, the user can interact with the navigation system and monitor its output on a display. The current ePINS prototype offers two-way communication via a serial connection. The serial communication is made wireless by the addition of a Bluetooth interface. Users can use this link to monitor the status of the navigation solution and to send commands to the device.
Honeywell has developed an application for the Android platform for this purpose. One of the key features of the interface design is that the navigation system outputs data in a standard NEMA format. Thus, publically available Android applications, not just proprietary applications, can also receive and display the navigation solution output by the ePINS device.
Honeywell’s personal navigation application displays the user’s traveled trajectory in real-time. The application can be adapted to include building floor plans as well as other navigation information.
Results
The ePINS prototype has been evaluated both in simulations and indoor/outdoor experiments. The navigation results presented here were obtained in February 2012 at a Honeywell facility (FIGURE 8). First, the user completed the heading calibration, and then online step parameter estimation in the presence of GPS was performed. Once calibration and training was completed, the GPS was disabled to simulate a GPS-denied environment outdoors. The user than transitioned to indoors (with GPS still disabled), and walked a course inside that included walking up and down stairs (FIGURE 9) and ended in a conference room (FIGURE 10).
Figure 8. Course for the Honeywell facility demonstration.Figure 9. The user walking up stairs.Figure 10. The user at the end of the demo.
Over these conditions, the ePINS system performed robustly and within performance specifications. Live demonstrations and testing showing similar levels of performance were performed at the 2012 Joint Navigation Conference (JNC) and at military test sites in California and Indiana.
Summary
The technical approach of the ePINS solution to the problem of personnel navigation in GPS-denied environments is based on a strapdown navigation solution maintained using a mid-grade IMU and advanced motion-classification algorithms. We integrated an array of sensors and software into a system that provides accurate position information and is suitable for use by first responders, soldiers, and other personnel where GPS is unavailable. ePINS works well for a variety of pedestrian motion types, including walking, running, crawling, walking upstairs, walking downstairs, sidestepping, and walking backwards. The motion classification and modeling method is extensible to other motion types.
We tested the ePINS system in indoor and outdoor environments. FIGURE 11 depicts the future ePINS concept, and TABLE 2 presents its future physical characteristics.
Figure 11. Future ePINS concept and mounting position.Table 2. Packaging characteristics of the future ePINS.
Acknowledgments
This article is based on a presentation made at ION GNSS 2012.
Manufacturers
The ePINS processing platform uses Honeywell Agile Navigation and Guidance Integrated Electronics support electronics. It includes a Honeywell HG1930 MEMS IMU, a Bosch Sensortec BMP085 barometric pressure sensor, a Honeywell HMC6343 digital magnetometer, and a NovAtel OEMStar GPS receiver.
Yunqian Ma is a principal scientist at Honeywell Aerospace. He received his Ph.D. degree in electrical engineering from the University of Minnesota, Twin Cities. He is currently the program manager of the GPS-denied navigation program and the next-generation personal navigation program.
Wayne Soehren is a senior technical manager at Honeywell Aerospace. He was the program manager for the development of Honeywell’s first MEMS-based GPS/INS, which developed the core capability now used in Honeywell’s IGS-2XX family of MEMS-based GPS/INS products. He holds an MSEE from the University of Minnesota.
Wes Hawkinson is an engineering fellow at Honeywell Aerospace. He holds a BSEE/CE from the University of Wisconsin–Madison. Justin Syrstad is a guidance and navigation scientist. He received a master’s degree in aerospace engineering from the University of Minnesota.
Presentation to the 11th Meeting of the PNT Advisory Board
The following is an abbreviated transcript of Don Jewell’s briefing to the PNT Advisory Board at its meeting on Tuesday, May 7. The slides from Jewell’s briefing and the other briefings to the board are available at pnt.gov under the heading 11th PNTAB meeting.
First, a prefatory note from Don Jewell:
Author Sets the Scene
The old adage “A picture is worth a thousand words” certainly applies to the atmosphere of a PNT Advisory Board meeting. And in this case, so does the oft repeated and entirely inadequate phrase “You had to be there.”
The atmosphere of an Advisory Board meeting is extremely dynamic. You have a very distinguished board of PNT subject-matter experts who are very passionate about their areas of expertise. Some, like Drs. Parkinson and Schlesinger, the co-chairs, have been involved with PNT and GPS matters for 45 years or more. Therefore, the danger of an abbreviated transcript of an emotion-filled briefing is always unsatisfactory at best, because you miss the give and take, the repartee of experts that have invested much of their lives in this arena. So it is important that the reader understand the context of the questions and answers and sidebar conversations that took place before, during, and after the briefing, to put it in context.
It would be easy after reading this transcript and others during the meeting to put the blame for antiquated PNT equipment on the manufacturers. But nothing could be farther from the truth. The truth is, the culprits here are numerous but identifiable. They are:
1. Outdated government regulations, directives and procurement/acquisition procedures that seriously hamper equipment manufacturers from doing their best and updating equipment as necessary.
2. Timelines that totally ignore the dynamics of Murphy’s Law — a law of ever-shrinking timelines battling a glacial process of ever-increasing requirements bounded by antiquated procurement procedures and fiscal indecision.
In the case of military user equipment (MUE), the warfighters, first responders, and government users are the unfortunate recipients of this morass of near-pandemonium and downright confusion. Dynamic and critical user requirements are sacrificed upon the altar of “the program of record” and an agonizingly glacial government bureaucracy. Be assured that the “program of record” delivered exactly what was asked for by the original RFP and subsequent contract award.
Take Rockwell Collins for instance. Rockwell is a great company, building rugged, reliable, precision instruments. I have flown with Rockwell communications and aviation equipment in various aircraft cockpits for the last 40 years, and they are indeed the gold standard in that arena. Rockwell has been delivering GPS military user equipment since 1978 and the company has always delivered exactly what was asked for. The problem is that the operational and refresh cycle for government user equipment needs is inside the acquisition cycle, and unfortunately exceeds it by a factor of ten — hence Murphy’s Law.
The Defense Advanced GPS Receiver (DAGR) was an excellent device when conceived and was the only game in town as regards jamming and spoofing environments. I am confident that Rockwell would have continuously updated the DAGR and made it relevant today, given the opportunity, which they were not.
In my opinion, government regulations in the area of user equipment, especially electronics and highly dynamic technological areas, need to be drastically altered to follow the aircraft procurement cycle. For example, there are probably 50 or more different block versions of the F-16 aircraft, that in truth are radically different. In some respects the “Block 1” F-16 resembles the capabilities of the “Block 50” version only in that it is an airborne vehicle with wings, engine, and a fuselage. Electronically and technically, it is a totally different aircraft. But the contracts for General Dynamics and now Lockheed Martin were not recompeted every time the user requirements, and hence the capabilities of the F-16 changed. I hope you all agree that would be ludicrous — and yet that is exactly the situation with MUE. When the scope changes, the contracts are painfully and laboriously recompeted, with lag times that make the process laughable — if indeed it were not so sad.
Then there is the government’s serious lack of information and training concerning MUE devices. I have been around GPS user equipment for 35 years and yet I am sure I still do not understand all the capabilities of the Precision Lightweight GPS Receiver (PLGR) and DAGR. Imagine how befuddled a young warfighter becomes when given the devices and only a cursory amount of training, that is not only inadequate but sadly many times misleading or just flat wrong.
In our interviews we founds trainers — those that taught warfighters how to use the PLGR and DAGR — who were not aware the unit could be “keyed” or encrypted for greater accuracy. Of course we also found excellent trainers, but they were the exception to the rule. Who trains the trainers?
Although it sounds trite and seems to be a copout, don’t blame the equipment manufacturers for the current state of MUE. Blame the system and then get involved and help us change it to what it should be.
Good morning, everyone.
A special thanks to Jim Miller, Dr. James Schlesinger and Dr. Bradford Parkinson for inviting me to speak this morning on the future trends of PNT user equipment, particularly as it pertains to warfighters and first responders — certainly a subject I have been passionate about for only…oh, let’s say about 35 years.
Why GPS World?
Ever since the agenda for the PNT Advisory Board meeting appeared online, I have been receiving emails and phone calls asking why I was speaking not as one of the IDA (Institute for Defense Analyses) subject-matter experts on GPS but as the Contributing Editor for Defense for GPS World. Frankly, the answer is simple. Wearing the GPS World hat gives me the freedom to say what needs to be said today, whereas the IDA think tank attribution and publication rules, which are absolutely necessary for an FFRDC (Federally Funded Research and Development Center) to operate effectively and efficiently, would unduly restrict my comments.
Plus, for 21 years GPS World magazine has been the publisher of the definitive GPS user equipment survey for global users. It’s free for everyone to use, and it covers PNT receiver information from 55 global manufacturers with data on all aspects of 502 PNT receivers. And it is a great boon for me personally, as I only receive on average about 50+ emails or letters per month from users simply wanting to know what GPS/PNT receiver they should purchase. It is wonderful to be able to point them to the GPS World Receiver Survey.
Also wearing my GPS World hat, I can easily refer to the several thousand warfighter and first responder inputs we have received over the last 10 years — generally expressing what they would like to see in a GPS/PNT receiver or sometimes specifically the Perfect Handheld PNT Transceiver (PHPNTT), which I first wrote about six years ago (and most recently in December) in GPS World magazine.
Top 10 Warfighter – First Responder Requirements for the PHPNTT
Adhering strictly to the latest fad in government briefing formats, it is now time for me to BLUF, or give you the Bottom Line Up Front. However, being a journalist, I also have to hold something back for the end. So here are the top 10 PHPNTT requirements, in order of preference, as submitted over the last 10 years by thousands of warfighters and first responders:
Mil-Spec rugged – solid state drive – no moving parts
Friendly, intuitive, familiar interface – easy to use
Multi-GNSS – All signals available – space and terrestrial
SWAP friendly, long battery life, with solar charger
Real-time 3D map data, NGA, Google, satellite imagery
Not a stand-alone PNT device
Embedded in a computer with multiple communication capabilities – one must be secure
Must be able to download, store and utilize new applications
Software-defined and expandable
Act as a sensor with automatic reporting
All these “user requirements” are closely related to what our warfighters and first responders don’t like about the current GPS MUE or Global Positioning System Military User Equipment. I state that specifically because, make no mistake about it, the current MUE is strictly GPS-based. However, the current MUE only receives two of the many signals available today on the GPS SVs, and certainly not any of the other numerous PNT (position, navigation and timing) signals also available, which of course is the crux of the issue for user equipment of the future.
Most of the top 10 requirements, and there were more than 50 requirements identifiable in all, are self-explanatory, and time does not permit me to cover them all in detail. But bear with me for a couple of quick explanations. Certainly the rugged requirement is readily understandable, and there are numerous manufacturers around the globe today that make excellent Mil-Spec rugged devices. However, the one I am most familiar with and have been extremely happy with are the rugged units from Trimble Navigation produced in Corvallis, Oregon. Trimble also happen to be a certified SAASM (Selective Availability and Anti-Spoofing Module) supplier as well. More on those units later.
The second bullet concerns the human-machine interface on the current MUE, which is so poor that a Marine three-star wrote me a few years ago to say that in his opinion, “If anyone wants an example of how not to design an operational equipment interface then they should refer to the PLGR or DAGR. Both are consistently and sufficiently horrendous, in my opinion.” I could not have said it better. The PLGR and DAGR use the gold standard for PNT as a signal, but the human-machine interface (HMI) is, in my opinion and in the opinion of thousands of warfighters, so antiquated and non-user friendly as to be almost unuseable. However, the units do work well and provide outstanding signals when embedded with other equipment. They just do not work well as a handheld device. The other items on the list we will cover as we proceed through the briefing.
GPS MUE Historical Perspective
I have been involved with GPS user equipment for the last 35 years, and this behemoth of a receiver was my first unforgettable encounter.
Yes, this huge device is GPS user equipment. Can you imagine? It weighs more than 300 pounds, without the two operators, and was the very first workable GPS receiver produced for the U.S. military by Rockwell Collins, who has been producing GPS MUEs ever since. Which is an example of the prodigious acquisition issues that also need to be addressed, or corrected, if you will. Our antiquated acquisition practices are to blame for many of the failings in MUE equipment today. While I feel it is critical to mention this as a major contributing factor to the state of MUE today, it is also a story for another time.
Other than being the first GPS MUE, the significance of this huge receiver is that in my estimation it is the first and last time the U.S. military possessed a purpose-built military GPS receiver clearly superior to the products being produced by commercial and civil manufacturers for global users.
First Significant Usable and Transportable GPS Civilian Receiver
Fortunately, a good friend and colleague, both at IDA and ION (Institute of Navigation), Philip Ward, came to the rescue of all GPS users in 1981 when he delivered the TI 4100 NAVSTAR Navigator Multiplex Receiver.
The TI 4100 was indeed the first commercially viable receiver that could be considered a transportable by anything other than an aircraft. To be historically correct, there were some backpack models that were very short-lived and not as significant as the TI 4100. The main unit and two antennas weighed approximately 50 pounds and showed promise in station wagons and helicopters. I can see a few folks in the audience smiling, so I will reiterate that the TI 4100 was a significant milestone, both in SWAP (size, weight and power), accuracy and TTFF (time to first fix). TTFF was 15-20 minutes in search mode, however; after the four SVs were located and the unit was initialized, it could consistently present a fix location in just a couple of minutes. Plus, the TI 4100 was immune from most jamming signals of the day — an impressive receiver and accomplishment for 1981.
Evolution of Commercial GPS/PNT UE
Fast-forward several years and the following picture presents a view of how quickly GPS UE developed.
The first unit on the right in the above photo is a Trimble unit that was about the same size as the TI 4100, but considerably more capable. As you follow the units around counter clockwise, you will see that they decrease in size and weight, but what you can’t see is that they also increase incredibly where acquisition and processing speed (TTFF), accuracy and capability are concerned. Note also that you start to see stand-alone units that appear to be antennas with separate handheld display units. This is a feature the commercial manufacturers incorporated over 20 years ago, and in some respects a feature the MUE manufacturers and services are just now considering.
Note also the Garmin GPS wrist receiver (right), which until 2005 was the most prevalent civil receiver in both of the wartime AORs (Area of Responsibility). Compare this Garmin wrist unit to the 300-pound Rockwell Collins unit I first showed you and consider that where SWAP and performance are concerned, the wrist unit is hundreds of times more capable and portable.
Current MUE – Program of Record and the Future
The pictures below depict the current MUE – Program of Record equipment, again both manufactured by, you guessed it, Rockwell Collins. First is the PLGR or the Precision Lightweight GPS Receiver. Second is the DAGR or Defense Advanced GPS Receiver. The third unit, known simply as the “Puck,” is what the U.S. Army would like to field in the next couple of years along with that separate display unit I spoke of earlier. Starting to sound very commercial, right? By the way, the Puck measures only 2 x 2 x 1/2 inches and weighs just a few ounces.
Between the PLGR, which was decertified by the Marine Corps in 2010, and the DAGR, there are approximately 500,000 of these MUE devices fielded today, and yet almost none of them are utilized as handhelds. Our research shows that indeed only 1 in 40 is used as a true stand-alone handheld. Most DAGRs are primarily used to interface with legacy communications equipment, primarily U.S. Army, that calls for fire support, read ordnance, and all the others are either stored or embedded with other equipment, which means the “horrendous user interface,” a common warfighter description, is not a major issue. The bottom line is the DAGR is very good at what it does, it is just that what it does (warfighter quote) “…stopped being functional, when compared with other more capable PNT equipment, almost the day is was delivered to the AOR in 2005.”
While the Puck is certainly a major improvement in SWAP and concept, it essentially provides the same two GPS signals and SAASM capability as provided by the DAGR, just in a smaller form factor, and it does away with the continuously vilified user interface. The Puck technology totally ignores current-day PNT, multi-GNSS platforms and the other 160 PNT signals available today. Review the GPS World 2013 Receiver Survey and you will only find a handful of receivers that are so incredibly limited, and they are invariably produced, you guessed it, for the U.S. government as part of a GPS program or alternate program of record.
MUE: How Not to Build a PNT Device, or Why Warfighters Use Garmins and iPhones
The list you are looking at now is comprised of the first 15 minutes of conversation with thousands of warfighters interviewed over the last 10 years — they just had to tell us what was wrong with the current MUE before they finally got around to telling us what, if they were king or queen for a day, they wanted to see in the PHPNTT. This is not my opinion but the actual words of the warfighters. First of all, understand that the PLGR is a single-frequency GPS-only receiver with a security module (PPS-SM) to access encrypted P(Y)-code for anti-jam purposes. It was initially fielded 1990-2004, replaced by the DAGR in 2005. There are approximately 165,000 PLGRs and 450,000 DAGRs fielded at a cost of more than $1 billion. Now the warfighter comments:
Both the PLGR and DAGR have an antiquated, proprietary OS and “extremely unfriendly — non-intuitive” user interface.
PLGR and DAGR are not functional as handheld units but function well as embedded devices — although typically not networked, and we are not even sure they can be networked.
Example: One STRYKER vehicle variant has nine separate DAGRs incorporated, each with its own antenna and operating totally independently of the others.
PLGR was decertified by U.S. Marine Corps in 2010 due to friendly-fire incidents.
DAGR used today primarily as embedded device only with a “ horrible user interface”:
Monochrome screen, no active maps, navigation direct waypoint only. Provides user with PNT information as coordinates — requires paper map to be an effective tool.
For other than straight-line navigation — time, distance and ETA are incorrect.
Programming/mission planning require special cables, software and a laptop computer.
Additional cables, radios and hardware are required for PLGR or DAGR to communicate.
Proprietary OS — no capability for additional programs to be added or utilize.
SWAP issues — large, heavy, limited battery life (multiple batteries) for typical missions.
TTFF — warm, approximately 2 minutes; cold with almanac download, 30+ minutes.
Position accuracy expressed as PDOP (1-6) on separate screen from PNT data. Nominal accuracy of a coded DAGR is typically about 1 meter or more.
Advantages: Anti-jam and legacy interface capabilities.
So, the bottom line as far as the warfighters are concerned is that if you want to operate legacy equipment that requires a GPS input, such as calling in “fires” or artillery or if you are in a jamming environment, then you need the DAGR or its capability. Our survey shows, however, that only 1 in 40 use the DAGR as a handheld, and yet every single one of our respondents — that’s 100 percent, a rarity in statistics — stated they had a backup unit, primarily a Garmin, until 2005, and then popular backup units were more than likely an iPhone, iPad or Trimble unit.
One of the Most Popular PNT Devices in Theater Today – More than 365M Sold to Date
Today there is no question concerning the most prevalent PNT unit in both AORs. It is, you guessed it, the Apple iPhone and/or the Apple iPad. Let’s take a brief look at the capabilities of this non-ruggedized but still amazing device, which can easily be made Mil-Spec rugged with aftermarket cases and enclosures such as those produced by Otterbox, which I have personally tested and reviewed numerous times.
The attributes you see listed here are for the iPhone and iPad, and are those that assist in some aspect of PNT and/or integrity and accuracy.
Assisted GPS SBAS — WAAS (PNT)
Assisted GLONASS — (SBAS) (PNT)
Digital compass (PN)
Wi-Fi (Communications-Data + PNT)
Cellular (Communications-Data + PNT)
Bluetooth (Communications-Data + PNT)
Skyhook Wireless (PNT)
Three-axis gyro (PN)
Accelerometer (PN)
Pedometer (PN) – Application
Internet (Communications-Data) Skype application (PNT)
Real-time accuracy and integrity representation (PN)
361+ navigation applications in the App Store ready for instant download and designed for iPhone and iPad. The majority of these applications are available at no cost to the user.
All this capability available in just four ounces — truly a SWAP and capability revolution.
Apple logo
Of course, what really makes the list of iPhone and iPad capabilities revealing is that the first two attributes alone more than double the number of PNT signals received and utilized by the iPhone versus the DAGR, and that number does not account for the GPS L2C (second civilian signal) and L5 (DOT safety of life signal) with CNAV, which when activated will be the strongest GPS signal broadcast to date. The CNAV data is an upgraded version of the original NAV or navigation message. It contains higher precision representation and nominally more accurate data than the nominal NAV data. There are 26 more PNT satellite signals available today in the iPhone and iPad, and they are comprised of multi-GNSS signals and augmentations. The kicker for me is that in addition to all the additional space signals are terrestrial signals, and almost any map or grid system the user desires. Plus there are apps (software applications) that translate between grid systems. And if you don’t like the interface of the navigation program you are using, then there are literally 360+ other choices. I also find the pedometer function interesting, in that firefighters now use this capability along with the Blue Force Tracking app in buildings when they are momentarily without GPS, GLONASS (Russian GNSS), WAAS (U.S. Wide Area Augmentation System), EGNOS (European Geostationary Navigation Overlay Service) or other SBAS (Satellite Based Augmentation System) signals.
Realistically, to defeat the current unencrypted MUE today, an adversary only has to jam one GPS signal, but to defeat the iPhone or iPad an adversary has to jam all the GPS signals, all the GLONASS signals, all the Wi-Fi signals, all the mobile 3G and 4G CDMA and GSM (read as different mobile telephone systems) signals and still the iPhone or iPad will use the accelerometer, gyro, compass and pedometer functions to determine position. Indeed, it will continue to function as a PNT device. All this in just four ounces at a cost about one-sixth of the DAGR displayed on a screen that has 100 times greater resolution and is in color. Remember, the DAGR has a monochrome screen. No contest. Plus try saying, “Take me home, Siri” to a DAGR and see what happens.
Garmin
What about Garmin, you ask? At the beginning of the current conflicts, Garmins were the prevailing additional PNT device. There are still thousands of them in theater, and they have saved many lives, as we will see. However, just look at this sales chart for smart PNT devices.
ProductsTotal Units Sold (approximate)
iPhone (since 2005) 250,600,000 (M)
iPad (since 2010) 115,000,000 (M)
Garmin Sales ~100,000,000 (M)
iPhone/iPad App Store (since 2008)
Downloads of the 361+ navigation apps 2,200,000,000+ (B)
(Note: Total App Store downloads will exceed 50 billion by the time this is published.)
The Future
The future of PNT devices globally, especially for warfighters and first responders, is clearly with rugged mobile devices capable of downloading, storing, updating and utilizing applications. The Garmin cannot do that, although it can be updated, and just look at the numbers. Garmin started business as a GPS device provider in 1989. In that time, while branching out into marine and aviation devices, some of the best in the world for those purposes, they are still primarily GPS only (with SBAS). They have sold approximately 100M devices in 24 years compared to Apple’s iPhone and iPad numbers, which total more than 365M devices in less than eight years. The iPad alone outsold all Garmin products in just three years. I confess that I happily own several Garmins, think that are fantastic PNT devices, and it is really tough to beat the $99 wrist Garmin. When all is said and done, the Garmin gives you better information in a non-jamming environment than the DAGR. And Garmin units are still saving lives. Take this vignette from SSG Kyle Dorsch:
“My name is SSG Kyle Dorsch…a Reconnaissance team leader in the 2-30 Infantry Battalion, 10th Mountain Division, deployed to the Logar province, Afghanistan. I have used my Garmin eTrex Vista H throughout my deployment…it has been a lifesaver in more than a literal sense. In fact, there isn’t a leader in our establishment without a Garmin product…my Garmin guided me and my four-man team seamlessly through some of the toughest areas of Afghanistan…it also literally saved my life.”
SSG Dorsch goes on to explain that the eTREX, which was placed strategically on his combat vest, actually stopped an enemy bullet meant for him, and just like Timex the eTREX kept on ticking.
My Obligatory Caveat
Note that SSG Dorsch has always had a Garmin with him in theater and indicates that his leadership has as well. There is no doubt the eTrex saved his life, literally. However, I would never tell a warfighter to not use their government-issued MUE. In a severe jamming environment, it may prove to be a lifesaver, and it may be the only equipment that interfaces with legacy communications and fire support equipment. Take that advice for what it is worth today, because hopefully this will not be the case much longer.
DARPA and Smart COTS Devices on the Battlefield Now
DARPA (the Defense Advanced Research Projects Agency, the real inventors of the Arpanet and the Internet), a much-storied DoD research arm, launched an effort recently called “Transformative Apps.” It developed a few dozen smart applications that work on a number of mobile devices. In addition to mapping, navigation and smart routes, the apps identify explosives and various weapons, and help navigate and locate parachute drops.
A screenshot of the DARPA Smart Routes application. The green routes are safe routes and the red are routes that have been traveled too many times or indicate where problems may exist.
DARPA builds prototypes that are transferred to the Services and become official applications used by hundreds of thousands of warfighters. The challenge is to rapidly adapt COTS (commercial off-the-shelf) technology to the unique circumstances of the military, which often operates over large, hostile areas with little to no formal communications infrastructure.
DARPA reports that more than 1,000 war fighters in Afghanistan now use the DARPA Transformative Apps technology as it continues to be rolled out to the Services.
The most interesting aspect of DARPA’s participation in PNT software is that it will definitely accelerate the multi-GNSS and all-signals-available scenario, because it is not constrained by woefully out-of-date DoD regulations. DARPA does what is smart, what cutting-edge technology will support, what makes sense, and ultimately what saves lives.
The U.S. Department of Defense expects in coming weeks to grant two separate security approvals for Samsung’s Galaxy smartphones, along with iPhones and iPads running Apple’s latest operating system — moves that would boost the number of U.S. government agencies [ed. legally] allowed to use those devices.
In my humble opinion, this announcement is simply outstanding…albeit about 10 years late to need. Indeed, Ms. Teri Takai, the current DoD CIO (Chief Information Officer) gest it and is trying hard, but she can’t do all the heavy lifting alone.
Old Adages Die Hard
I remember an old GPS adage that portentously proclaimed, “If it is not supported on the GPS satellite, it cannot be supported in the user equipment.” Unfortunately, there are those still holding to this totally fallacious belief. Today in the current budget environment, amazing capabilities are being implemented with user equipment that multiply the capabilities of the PNT satellite, other satellites and space signals, terrestrial signals and synergistic augmentations. Indeed, the total price of the PLGR and DAGR program combined would barely pay for some NRE (non-recurring engineering) costs and two launches of the GPS III satellites that should be ready for launch in 2014. Today we need to look even harder at what is doable with user equipment, especially in the military, because it is all we can afford. As Winston Churchill was once quoted as saying, “Gentlemen, we have run out of money; now we have to think.” However, having said that, let’s not forget that the multi-GNSS environment has multiplied many fold the number and capabilities of PNT signals on orbit today.
PNT User Equipment TRENDS — Space SIGNALS available
Jim Doherty, USCG Captain retired, and I are friends and colleagues at the Institute for Defense Analyses (IDA). We are both old retired navigators as well. We both still have the skills to successfully navigate an aircraft or ship, for that matter, from San Francisco to Tokyo using only a sextant. While we are proud of that talent or ability, one that very few possess today, we would much rather accomplish the feat with an exceptional multi-GNSS device, and they exist today like never before. These next lists show all the signals that are available today compared to what the GPS MUE can receive and use for PNT purposes. Plus, Jim and I both share a firm belief in another old navigators’ adage: Receive Everything – Trust Nothing!
Civil-commercial multi-GNSS UE receives more space and terrestrial signals than U.S. GPS MUE.
GPS MUE “officially” utilizes L1(CA), L2 P(Y) with SAASM.
There are NO commercially viable M-code receivers available today and there will not be for several years to come.
PNT civil UE philosophy: Track and use all PNT signals available.
GPS L1-CA/L2-codeless and ready for L2C, L5, L1C (GPS III & QZSS)
SBAS (WAAS, EGNOS, MSAS, GAGAN, SDCM) + NDGPS & many other augmentations
GLONASS L1/L2/L5
Galileo E1/E5 (CBOC & Alt BOC)
Compass B1/B2/B3 (carrier signals only- no full signal specifications)
And do not be deceived: there are plenty of PNT receivers available today to receive all these signals and they have existed for some time. Equipment manufacturers have been ready to receive, process and utilize all the GPS and multi-GNSS signals for years. For example, Trimble built and shipped an L2C receiver in 2003, and that signal has still not been activated on any U.S. GPS payloads although, as we heard from Major General Marty Whelan (USAF – AFSPC/A5) earlier today, General Shelton (USAF), the four-star commander at AFSPC (Air Force Space Command) has announced a six-week test of the L2C signal and full CNAV message in June of this year. A great step forward.
One of these days we might even catch-up with the Japanese – more on that in a moment.
Trimble built and shipped receivers for GLONASS signals in 2006, even though GLONASS did not reach FOC or Full Operational Capability until late in 2010. A designation it is having serious problems maintaining. Trimble also ships L5 receivers as well as commercial SBAS receivers that result in extremely accurate and reliable positions. Lest you think all these signals have gone to waste, remember that Japan’s QZSS-1 broadcasts both L2C and L5 with a full CNAV message today, and the Trimble receivers and others with the multi-GNSS capability work well with those signals, as we shall see.
Global Virtual Reference Stations
Trimble (VRS) and John Deere (StarFire) PNT receivers have the capability Trimble has designated as Global Virtual Reference Stations, which — along with real-time kinematic (RTK) processing — provide users with an unprecedented number of signals and a real-time processed signal with corrections. This results in centimeter-level accuracy for any of their receivers that have the capability to receive and process the signals. For both manufacturers, that will soon be almost all of their receivers. Sure, there will probably be a small monthly fee involved, but the accuracy difference between 1 meter (~3 feet) and 3 centimeters can mean life and death if you are unlucky enough to be in the collateral damage zone or in the sights of a Hellfire missile during war time.
Multi-GNSS SVs and Signals in View
To highlight this point, just glance at the following graphical log file generated by software in the latest Trimble Multi-GNSS PNT receiver. The chart depicts a log file from a receiver located in Singapore. The location is significant only because in that location the receiver is in full view of the Japanese QZSS-1 PNT SV and all its extra U.S. originated PNT signals (L2C & L5) mentioned earlier. This particular Trimble receiver is networked and reports results automatically and continuously to a web page, while receiving GVRS updates and corrections plus other PNT information, such as an updated almanac, over the same network. The question becomes, is it a PNT device with a computer and embedded communications? Or is it a computer with communications and an embedded PNT function? You be the judge. Regardless of which you choose, this is the future of PNT and MUE.
This civil receiver reports 40+ SVs with 169 separate signals in view and usable. This does not count the number of Wi-Fi and/or GVRS signals it is capable of receiving. Meanwhile, a GPS MUE receiver in the same location only observes a total of 10 SVs it can process for a total signal count of 20. However, one of the key points on this log depiction has to do with integrity. Notice the orange and red lines. They indicate that the receiver has labeled these signals as “suspect” and has automatically dropped them from the solution for any of a host of reasons — a failed integrity check, jamming, spoofing, wrong way path, a runaway clock, etc. You name it, and if it is suspicious, the receiver will drop that SV and its signals from its PNT calculations. Built-in integrity.
The obvious question becomes just how accurate is this Trimble receiver over a 24-hour period? The next graphical log file denotes that it is accurate within 3 centimeters.
Trimble multi-GNSS receiver web page log file denotes continuous availability of PNT signals with an average accuracy of 3 cms.
Assured PNT
When we asked warfighters what was more important to them in a combat zone — availability or accuracy of the PNT signals, the answer was, not surprisingly, both. But, of course, they need to receive the signal first, and then they can worry about accuracy.
So, if you were Ms. Teri Takai and you were worried about “assured PNT,” would you rather do that with 20 signals from 10 SVs or 169 signals from 49 SVs and some very strong, difficult to jam, terrestrial signals as well — adding up to, on average, 33 times more accuracy than the GPS-only signal? To me, the answer is obvious. And of course, all that is on the line with every mission the DoD performs, as is the safety of our critical national infrastructure as this next chart depicts.
Assured PNT or lack thereof impacts all missions, across all platforms and domains
Assured GPS MUE PNT today depends on:
L1(C/A), L2 P(Y), SAASM (Future M-Code)
Accuracy ~ 1m
Assured Multi-GNSS MUE PNT with all signals available depends on:
GPS L1/L2/L5/L1C/L2C/M-Code/SAASM
SBAS (WAAS, EGNOS, MSAS, GAGAN, SDCM+)
GLONASS L1/L2/L5
Galileo E1/E5 (CBOC & Alt BOC)
Compass B1/B2/B3
QZSS GEO – L1 CA/C/SAIF, L2C, L5, LEX Pilot
Two-way communications, Networking, PNT servers, each PNT device with unique IP address and each PNT device serves as a sensor
Software definable devices
Multiple software applications (Apps)
Accuracy ~ 3 cm
Army Making Strides
I spoke above about DARPA getting into the PNT business, and that is a good thing. But how about the largest military user of PNT, the United States Army? The U.S. Army is making some interesting changes as well. The Army announced a few months ago that there would be no more purchases of DAGRs, and that it was pursuing smartphones as a communications and small computing platform as well as an alternate PNT tool and display device. This is where the Puck comes into play.
While it is a wonderful idea I fully endorse, the problem with the Puck is that under the current design scheme it will still only transmit the current two GPS signals to a smartphone or other PNT display device. And warfighters lament that it is another device run by batteries for which our warfighters need to carry spares. Why not make the Puck a multi-GNSS device? we asked. The answer we received is that it would make it too power hungry and just require more batteries. So to misquote Shakespeare “…for want of a battery, the war was lost?” The Army is definitely on the right track, but they need to figure out how to make the Puck a multi-GNSS device. Can you say Lithium ION and solar charger – Hoorah!?
The Army Hub
The Puck is moving in the right direction. However, with the addition of another device, the Army is definitely on the right track. This device is designated the “Hub,” and while it is again GPS-oriented, it contains multiple terrestrial and internal signal augmentations and backups, as the image depicts.
With apologies to the U.S. Army, I unabashedly modified the chart, and I made it very obvious. The red text depicts my addition of a multi-GNSS card or module versus or in addition to the CGM (Common GPS Module) and GB-GRAM or Ground-Based GPS Receiver Application Module. The multi-GNSS card/module already exists today. Several PNT receiver manufacturers manufacture it with 28-nm technology versus the 95-nm technology — for the as-yet-unavailable for about four more years if the rumors are correct — GPS-only CGM. For me, the addition seems to be an easy fix, as there is lots of room in the Hub. But this fix or module (CGM) is years and millions of dollars down the road, versus a solution that exist today.
YUMA 2 or Hub or Both
The solution, frankly, is one of the smart tablets available today from numerous manufacturers — seven, actually, that have the wherewithal to produce a secure multi-GNSS device with a SAASM module.
The Trimble Yuma 2.
This is an example of the solution in the form of a Yuma 2 tablet computer from Trimble, which I am in the processing of reviewing for GPS World. The Yuma 2 has all the multi-GNSS features we have been discussing and more, plus it can in time accommodate all the modules scheduled to be incorporated into the Hub. Why build a whole new display device when the core already exists with many more capabilities than were imagined or real estate would ever allow for the Hub? Plus, it is available today as a rugged Mil-Spec device with a full color, high-resolution touch screen. And in the end it will provide a 3-cm solution versus a 1-meter solution. What more could you want? And it is available today with an outstanding and intuitive interface.
Conclusion – Services PNT UE Trends
I have been focusing on the Army today not simply because they are the biggest U.S. military user of PNT devices, but because they are moving in the right direction for the future of PNT and MUE devices. Of course, all the services and many agencies need a well-thought-out and secure PNT solution, and if we have learned anything it is that one size does not fit all. Indeed, our national security and our national infrastructure depend upon future PNT devices. For security purposes alone, they should have a certain degree of application and signal diversity.
Now let’s review:
Army has a way ahead with an assured PNT program.
Includes end of PLGR and DAGR and adding new networkable devices.
Plans for fourth-generation multi-GNSS and multi-function handheld devices and embedded PNT devices as sensors to include the Puck and Hub.
Marine Corps: Decertified PLGRs in 2009 and attempts to limit the use of DAGRs.
DAGRs used primarily as embedded devices.
Purchasing approved SAASM devices from commercial vendors.
USAF: Outfitted 70% of aircraft with modern, integrated, networkable and upgradeable PNT devices.
Navy: More than 60% of the fleet outfitted with modern PNT networked devices.
The Bottom Line is – One size does not fit all but one conclusion is clear – while GPS may and will always hopefully be the Gold Standard – multi-GNSS solutions are the future.
The Future of PNT Devices
This last list depicts the future of PNT as best as I can define it; indeed, as it has already been defined for us by our warfighters and first responders or, as Kirk Lewis would have me say, government users. The users are not waiting around, nor have they bothered to adhere to woefully out-of-date regulations. It is what they desire, and since their lives depend on it, it is what they should have.
Multi-GNSS — Utilize all PNT signals available.
Space and Terrestrial (GPS, GLONASS, eLORAN).
Traditional and non-traditional (Wi-Fi, GVRS, carrier signals).
Multi-function COTS devices with non-proprietary OS (operating System), intuitive interfaces and Mil-Spec ruggedized.
Multiple methods of communications: Wi-Fi, Skype, 4G, text, auto-text, satellite.
Software Downloads – Applications
COTS applications plus .mil apps store.
Networked devices for SA, updates and PNT,
Real-time satellite imagery and mission data injects.
Defense and intelligence LBS.
Each device will be a sensor on a network,
Automatically report jamming, interference and location data.
Utilize SAASM and anti-jam military signals only as required.
Thanks you for your time and kind attention today. And remember, Happy Navigating!
GPS Source, Inc., has released the latest addition to its military product line, a military qualified, in-line GPS amplifier, MA11M.
The MA11M is a military-grade device used to strengthen the signal and reach of GPS. It is designed for GPS conditions where there is a weak signal. This amplifier is designed to work with an external, active antenna, and is primarily for use by military applications (both ground and air) around the world.
“GPS Source realizes the importance of protecting our national assets by designing products that can handle rigorous military environmental demands,” said Robert Horton, CEO of GPS Source. “This amplifier has been qualified for temperature, altitude, explosive atmosphere, humidity, vibration, among many other challenging conditions. The qualifications allow the military to use this device without reservation. Test summaries (MIL-STD-810 and EMI) are available upon request.”
The ruggedized MA11M GPS amplifier is designed with the thin link margins of satellite navigation systems in mind, and is a single-stage gain block that covers the GPS, Galileo, and GLONASS frequencies. The device features 30 dB of gain and excellent gain flatness of less than 1 dB.
This year’s GPS Partnership Council provided among other highlights a discussion of the tensions between commercial off-the-shelf (COTS) receiver systems used in tactical combat operations versus official military GPS user equipment (MGUE), and an enthralling warfighters’ panel that revealed much of those COTS/MGUE dilemmas. The event, held May 1–2 in El Segundo, California, drew an enthusiastic and involved audience, including many GPS veterans. I was struck by the graying of the clan as well as the practiced and confident presentations of current civilian and military program staffs.
Keynote speaker Brig. Gen. Martin Whelan, Director of Requirements, Headquarters Air Force Space Command, emphasized that ideas for improvement of the system would be hard sells under current budget realities, but good ideas for lower cost would be welcome. Referring to the three segments — space, ground, and user — he recommended that the segments should talk with each other and challenge requirements. In effect, he implied that the separate segments could reduce overall costs, rationalize requirements, and cooperate better in optimizing the resilience and flexibility of the system, including — this is my interpretation — taking advantage of the “competitive” GNSSs to effect user satisfaction.
According to Whelan, resiliency of the space segment is a top priority; smaller satellites, hosted payloads, and net-centric designs were highlighted. He commented that multiple GNSSs should be employed in such a way that the user does not know the difference.
Regarding the upcoming budget, he told us that Department of Defense will be cut by 22 percent, the Air Force will drop 9 percent — but the AF space budget only 1.5 percent. A notable exception to the generally favorable overview was his comment that the MGUE segment, from a distance, looked uncoordinated. Much more along this line came up later during both days of the Council.
Widespread COTS. There was an air of defensiveness about the user segment, and many comments on both the success and the risks associated with the widespread use of COTS user equipment. We heard further commentary on the very infrequent use of SAASM keys, due to the difficulty of procedures to obtain and employ them, and due to the perception of very low risk of jamming and spoofing threats in current combat deployments.
A session on “The Future Military Receiver” enlisted two panels of government experts and contractors from Deere-NavCom, Garmin, IEC, Johns Hopkins Applied Physics Labs, Raytheon, and Rockwell-Collins. Although the unclassified nature of the presentations limited the level of detail, it clearly emerged that many tactical, in-combat deployments of COTS GPS receiver systems had occurred and continue to occur.
A video compared the jamming resistance of a Garmin receiver with that of approved GPS User equipment receivers. It showed a screen of the Garmin receiver losing satellites at greater distances from the jammer and losing lock at closer distances. Directorate employees and officers made several references to the risks from dependence upon COTS receivers, and related with considerable candor the difficulties with large, expensive, power-hungry MGUE, both mobile and platform-mounted, models of which were held up during the presentations — often to laughter from some in the audience.
More on this followed in Day Two’s dramatic warfighters’ panel, which many people felt was by itself worth the price of admission. These experienced users of GPS under fire — from Coast Guard search and rescue to Air Force forward controllers calling in air strikes within range of small-arms fire — related direct personal experience in a broad array of critical applications. They clearly knew how to use COTS equipment to good advantage and described the operational protocols developed from hard and sometimes painful experience.
Manipulation of multiple screens in a heavy device, which requires initialization or synchronization before dismounting, was often simply not an option. Translation of such experience into qualified requirements is a major challenge for the Air Force and Army. Overdependence on the anecdotal but very valid combat experiences would weaken a design against an enemy with even rudimentary jamming and spoofing capability.
An astute questioner asked “Have you seen any evidence that the enemy (in Afghanistan) has changed tactics because of our technology?”
The answer came “Not yet,” with a comment that the enemy’s early warning systems are very sophisticated and the target of a mission to capture a high-value individual (HVI) frequently knows that such a mission is underway; his support network spirits him away and attacks the mission with the advantage of surprise denied to our forces, abetted by the advantage of favorable terrain and numbers accruing to the enemy.
The Puck. The Army-led MGUE program status was described as being at technology readiness level (TRL) 6.0; the request for proposals was released on April 16. The key to the success across platforms of this “system of systems” was said to be the Common GPS Module (CGM), also referred to as the Puck. This module is M, P, and C/A code-capable and SAASM-capable but has flexible interfaces and “emulates commercial.” The module itself is a system-on-chip (SoC) that can be integrated across many platforms. Depending upon the level of integration employed, it can be as small as chips found in smartphones or somewhat larger.
The program schedule was defended as having only been funded two years ago and having very complex security and platform interfaces. This program presentation drew a large number of questions and commentary from the audience, much of it politely skeptical and showing impatience with the bureaucratic aspects of the program. Well-informed former military field-grade officers in the audience questioned its real availability. The answer that it would be available in quantity sometime in 2017 did not please the questioners.
In short, procurement regulations appeared to be the highest barrier to a rapid, flexible program for a net-centric, open-architecture system development.
Currently, the circuit boards for the MGUE are classified secret, but it is hoped to have these at a confidential or unclassified level for deployment by handling the encryption exclusively in software. The leader of this presentation indicated that software receivers were the ideal but were not available, so reduction in size, power consumption, and complexity in hardware was the goal.
Trumping Military. One almost nostalgic comment hearkened back to the time when military systems were regarded as the height of technological excellence, whereas it is now generally perceived that commercial systems trump the military in sophistication. Garmin claimed to have developed SAASM receivers in the lab but found little interest from business leaders at that time.
The CEO of Mayflower Communications, which makes and sells miniaturized SAASM receivers, pointed out that anybody could make a SAASM receiver employing a Sandia crypto-chip approved by the U.S. National Security Agency (NSA) but pointed out, as did several others, that the availability of certifications and authorizations was very limited, and that volume drove cost. Implicitly, NSA’s requirements and protocols got blamed for the limited distribution and use of SAASM receivers.
Day Two
The second day of the GPS Partnership Council comprised The Nation and The Warfighter. In the latter group came an outline of the Army’s COTS vision and — the hit of the entire conference — the Warfighter panel with a keynote introduction by a USAF colonel warrior now at the GPS Directorate.
The Nation. Tony Russo, director of the National Coordination Office for Space-Based Positioning, Navigation, and Timing, disabused those who thought that the apparent demise of the LightSquared threat had eliminated that subject from his agendas; he still deals with it often. He provided entertaining and informative examples of non-obvious and valuable applications of GPS, from assessing rugby players’ game performance through detection of clandestine underground nuclear tests to a social application of matching available part-time and temporary workers with jobs when labor demand surges and a roster shows where the closest qualified candidates are.
John Merrill of the Department of Homeland Security (DHS) identified 18 critical infrastructures that depend upon GPS integrity and showed the cascading effect of taking out sites like SCADA (Supervisory Control and Data Acquisition) systems. He related a threat-illustrative story of a DHS agent who required constant contact via his agency smart phone but who could not get reception while attending mass in church. The pastor later and very proudly showed him the mobile phone jammer in the sacristy; he had given up on asking parishioners to turn off their cell phones off during services.
James Miller of the National Aeronautics and Space administration noted that only 5 percent of space missions lie outside the GPS coverage envelope (3,000 kilometers to geostationary altitude of 35,800 kilometers is the space service volume). Reducing the burden on spacecraft tracking networks is a highly profitable application for GPS.
Warfighters Panel. These real-life experiences from combat and other vital operations could easily justify an entire article of their own. The following examples will illustrate the life-saving force multiplication of GPS, particularly the ubiquitous civil GPS technology in the current combat environment.
• An Air Force Special Operations Major described a mission to snatch an HVI, giving great detail on battlefield terrain, combat conditions, and how he worked between a COTS GPS receiver and a COTS handheld computer with Google Earth-like facilities to bring JDAMs (GPS-equipped smart munitions) onto an ambush mounted by defenders of the HVI, who were alerted to the raid by their extensive and sophisticated early-warning network consisting of sympathizers with cell phones. His description of the heroics of individual forward controllers, their injuries and fatalities, and the symbiosis of man and machine in a relatively benign electromagnetic interference but relatively malign electromagnetic propagation environment, and overtly and covertly hostile indigenous population, was dramatic and compelling.
Clearly, unsophisticated and easily-available high-power jammers rapidly alter such situations to reduce our technological advantages. Also clear was the need to design user equipment, not just to reject interference but to minimize time and the inevitable ambiguities in actual combat situations.
• A Coast Guard lieutenant described the search-and-rescue missions he flies out of local airports to Pacific Ocean sites. Again, COTS equipment, aided by the near-ubiquity of commercial GPS equipment, along with VHF marine radio on boats and ships, enhances these mission results over those flown with standard USCG-issued navigation equipment.
• An Air Force tanker pilot major now attached to the GPS Directorate described three personal experiences. He once had to ask his boom operator to retrieve the Garmin receiver issued in the survival kit in order to navigate the tanker for rendezvous with tactical aircraft needing fuel when the tanker’s standard equipment failed.
When tasked to fly into an airport in Afghanistan with unreliable navaids, under suddenly occurring zero-zero conditions, the onboard GPS enabled him to land safely.
In a third instance in Iraq, he observed a downed airman being approached by gunmen. The gunmen with AK-47s were being targeted by drone operators. The major was able to discern that these gunmen were friendly forces moving to rescue the downed airman and avert a friendly-fire disaster. The downed airman’s ability to send his exact coordinates were key to the ability of the observer to get close enough to direct rescue efforts and to avoid a fatal error.
• A Navy surface warfare lieutenant commander and a CWO Riverine or small boat skipper cited instances in which GPS was essential to missions and ways in which user equipment design could improve their operations — for example, by making it float.
All the veterans repeated, during or after their accounts of ways in which GPS saved lives or enabled missions, “thank you for what you do,” addressed to the audience, the presenters, and their leaders. Going into denied territory places a high premium on user friendliness, battery life, robustness, size, and weight. In the future, inevitably, jam and spoof resistance will be an object of gratitude, as well.
Final Review. We all know these things, intuitively and by doctrine, but hearing reports from people in harm’s way or retrieving comrades from harm’s way was a great addition to the usual program and technology descriptions by the development teams.
I was particularly impressed with the very articulate, sophisticated, and focused presentations of these combat veterans. It is highly incumbent on the industry and the government GNSS leaders to translate these experiences into design requirements quickly, so that future systems are less dependent on individual ingenuity and on commercial gap-fillers.
Much of this progress depends on truly incorporating the applications focus of commercial product development and on use of other GNSS systems for robustness, flexibility, and affordability — often quoted as mission goals by the leaders of this enterprise.
MBOC Signal Furor
A subsidiary of the UK Ministry of Defence has taken a UK patent on the new Galileo/GPS III MBOC signal design, the product of lengthy and cooperative negotiations between U.S. and European scientists. The patent, in the names of two UK engineers who participated in the project, is being used by a legal firm to demand royalty fees from receiver manufacturers, causing considerable controversy.
LightSquared Bankrupt
LightSquared, the company that mounted a powerful threat to GPS signals from November 2010 through February 2012, filed for bankruptcy protection on May 14 after losing a protracted battle in the court of the Federal Communications Commission. The war is not over, however. Exploding sprectrum demand for mobile data use makes it likely that future challenges to GPS and GNSS spectrum will emerge.
Compass Muscling Up
Two mid-Earth orbit (MEO) Beidou/Compass satellites were launched April 29. Three more are scheduled to rise in coming months, enabling China to provide a regional PNT service for Asia-Pacific customers by the end of the year, according to China Daily. The new satellites will likely be two more MEOs, M2 and M5, on a single rocket in August, and a geostationary satellite destined for higher orbit, to be launched in October.
NovAtel Inc. today announced the development of its OEM625S Selective Availability Anti-Spoofing Module (SAASM) GNSS receiver, a collaborative effort between NovAtel and L-3 Interstate Electronics Corporation (IEC).
System integrators have come to rely on the centimeter-level positioning accuracy made possible with real-time kinematic (RTK) commercial GPS receivers. Many authorized defense customers rely on access to the Precise Positioning Service (PPS) for single-point positioning. The OEM625S will combine a commercial dual-frequency NovAtel GNSS receiver with an L-3 IEC XFACTOR SAASM in a single card solution, reducing overall size and power requirements for end customer applications.
The OEM625S will maintain NovAtel’s OEMV-2 form factor, ensuring a successful drop-in replacement and backward compatibility for existing customers. Integrators can continue to use their existing user interface, which will be enhanced with OEM625S logs and commands for SAASM functionality.
NovAtel’s well-established, comprehensive set of software commands facilitates system integration, NovAtel said. The SAASM position is provided via a dedicated communication port, as well as through NovAtel’s software command protocol, allowing for maximum flexibility.
“For the past 17 years NovAtel’s customers have enjoyed great success in integrating our OEM family of high-precision receivers into a wide array of defense applications,” stated Graham Purves, executive vice president of NovAtel. “Adding the L-3 XFACTOR SAASM to our receiver card will allow defense customers to continue to use our products in the most demanding military environments.”
Ric Pozo, general manager of L-3 IEC’s Navigation Systems business unit, commented, “We are pleased to collaborate with NovAtel and provide the warfighter this highly flexible and capable GPS SAASM product. Our combined teams are looking forward to bringing this one-of-a-kind solution to market.”
NovAtel will accept orders for the OEM625S from authorized customers starting in the third quarter of 2012.
By Stéphane Gallot, Pascal Dutot, and Christophe Sajous
A new hardware assessment tool automates testing and mission replay, managing military GPS receiver input and output data, with an operational implementation and with a better control of initialization conditions, especially direct P(Y) acquisition. The test bench drives a GPS/Galileo simulator, a digital jammer, and software programs for visibility computation based on terrain modeling, and for multipath generation on 3D renderings.
Comprehensive assessment of military GPS receivers becomes more complex as they are integrated into advanced systems. To limit testing on systems under live conditions, laboratory evaluations with real elements are essential.
A new hybrid test bench called Statistical INERtial Gnss HYbrid in Simulation (SINERGHYS) is designed for governmental use to validate the integration of GPS/Galileo receivers within the navigation system for different platforms. As system-level requirements become more stringent, this bench has been designed to assess the behavior of the complete system in an operational context.
This new assessment hardware-in-the-loop tool is designed to automate testing and to replay missions with an operational implementation and with a better control of initialization conditions, especially direct P(Y) acquisition. This test bench drives many simulation tools: a GPS/Galileo simulator, a digital miniaturized jammer, and different softwares such as one enabling the computation of visibility depending on the terrain modeling, or one dedicated to the generation of multipaths on surfaces of realistic 3D scenes.
Figure 1. Depiction of SINERGHYS.Figure 2. Focus on the bench.
A Common Bench. Since 2000, with the arrival of the new cryptographic generation (the selective availability anti-spoofing module, or SAASM), the French government defence procurement agency (DGA) GPS laboratory decided to buy off-the-shelf GPS SAASM receivers that cover different form factors and applications. To test performance, it was necessary to acquire a test bench suitable for each GPS receiver. Testing procedures became more and more complex, and most of the manufacturer-provided benches could not perform every test required, such as direct P(Y) acquisition. To improve French expertise concerning GPS receivers, the DGA GPS laboratory decided to develop a common, generic test bench taking into account the integration constraints of each receiver. The perimeter of the hybrid test bench consists of a PC and a generic GPS test bench.
Figures 3 and 4 show examples of military GPS receivers integrated into the bench.
Figure 3. MPE-S (Ground-based application, Rockwell Collins).Figure 4. 1000S (Avionics,Thales).Figure 5. Embedded jammer.Figure 6. Jamming environment for a fighter aircraft. (Click to enlarge.)
Bench management is centralized, so test conditions are generic, and all simulation parameters are fully controlled. This enables users to display a unique view of the complete information and to be able to replay specific scenarios.
The bench manages military GPS receivers’ input and output data as described in the respective receivers’ interface control document (ICD) or interface specification: this enables, for example, the initialization of GPS receivers by sending precise time to facilitate direct P(Y) acquisition. This new bench is compatible with many GPS receivers with different form factors and applications.
Several receivers can be tested at the same time with the same software, so that the behavior of the GPS receivers can be compared in real time. Data from the different receivers can be observed on the same window of the graphic user interface (GUI). Specific data from ICDs can be displayed on the GUI. The user can visualize three different windows: the first is related to integrity, the second to alarms, and the third to cryptography. All the data output by the receivers can be recorded and replayed.
To facilitate and enhance trials on GPS receivers, the bench can use a Monte Carlo method, enabling sequentially and automatically chained scenarios, up to 10,000 test sequences, primarily for characterization of time-to-first-fix (TTFF).
Inertial navigation system (INS)/GPS hybridization in real time can be simulated via processing based on a Kalman filter of the information delivered by simulated INS and GPS. Loose and tight coupling can be selected through the GUI as well as filter parameters. The Kalman filter design is independent from the receiver and from the type of trajectory simulated. The user can decide whether the GPS receiver does receive aiding either from the simulated INS, or from the optimal navigation (output of Kalman filter).
Interfaces
The bench can interface with various external means and drive some tools and materials involved in the functioning of the bench.
With GPS Simulator. In the interface with the simulator, an intuitive GUI facilitates scenario preparation. When ready, SINERGHYS begins to drive the GPS simulator in remote-control mode. Any type of trajectory can be simulated with its operational environment modeled. The simulator outputs an RF signal to the receiver, and representative aiding, if required, by ethernet protocol to SINERGHYS.
With Jammer. Two types of interference signal generators can be used with the bench. Any available waveform can be generated. The bandwidth can go up to 20 Mhz for one generator and up to 80 Mhz for the other.
SINERGHYS is also compatible with a specific jammer called Embedded Jammer, designed to test vulnerability of GNSS systems (Figure 5).
The GPS receiver under test tracks the real GPS satellites combined with the simulated jamming signal. Thanks to the position and attitudes provided by the aircraft and to a modelized antenna diagram, the jammer computes in real time representative jamming that would be generated by real jammers.
This jammer works in two modes: localized mode (coordinates, jammer power, and waveform) and power profile mode. It was initially designed to be used inside an aircraft but can be used for laboratory testing as well.
The simulated environment is defined in the configuration software: waveform, emitter, scenario definitions (bands, number of emitters), and antenna diagram.
Four GNSS bands can be selected: GPS L1 and L2 (40 MHz) and Galileo E6 (40 MHz) and E5 (90 MHz). The embedded jammer can generate up to 14 simultaneous jammers per band, each with different waveforms. Therefore, up to 56 simultaneous jammers can be simulated.
The center frequency of the jamming signals can be chosen anywhere in the bandwidth. Modulation examples: continuous wave, broadband noise, binary phase shift keying), binary offset carrier (x,y), and so on.
Figure 7. Modulation examples.
External software interfaces fall under three categories.
Warfare. Electronic warfare software, which provides jamming coverage, performs a precise assessment of propagation (reflection and diffraction) of the interfering signals (depending on terrain modeling). Interference levels are transmitted to SINERGHYS during pre-processing.
Figure 8. Warfare GUI.
Satellite Tool Kit (STK). This software is designed to provide sophisticated modeling and visualization capabilities and performs functions critical to all mission types, including propagation of vehicles, and determination of visibility areas and times. STK generates paths for space and ground-based objects, such as satellites, ships, aircraft, and land vehicles. STK also provides animation capabilities and a two-dimensional map background for visualizing the path of these vehicles. Within SINERGHYS, STK is used for real-time visualization.
Figure 9. STK GUI.
Ergospace. This software is designed to generate multipaths, enabling the modeling of reflected paths of different satellite signals on surfaces of realistic 3D scenes. Pre-processed multipaths are sent to SINERGHYS and generated by the GPS simulator. The software is also used for real-time visualization.
Figure 10. Ergospace GUI.Figure 11. Example of the window showing the general state of the GPS receiver (c/n, svid, gram receiver and channel states, code and frequency tracked).
Operational Mission Characterization
The bench can evaluate and characterize receiver performance in most possible representative conditions.
Management of GPS Inputs/Outputs. Both black and red keys can be loaded inside the GPS receivers in both DS101 and DS102 protocols. This loading can be performed manually through key loaders such as KYK13 or DTD/ANCYZ10, but also through the host application with hexadecimal keys.
The bench can send commands to GPS receivers such as non-volatile memory erasure command, INS, precise time source, precise time and time interval (PTTI) activation commands, or choices between “mixed mode” and “all Y,” between “L1 primary” and “L2 primary,” and so on. Depending on user requirements, the bench can provide time, position, speed, almanac, ephemeris, or specific navigation sub-frames.
To test the jamming resistance of GPS receivers, it is essential to be able to provide INS aiding. SINERGHYS uses perfect or degraded aiding and adapts the format or the frequency for the considered GPS receiver.
Direct P(Y) acquisition functionality is an important case that needs to be evaluated. The GPS receiver needs a precise time to perform direct P(Y) acquisition. The time accuracy, from a few nanoseconds to several milliseconds, has a strong impact on the GPS behavior. A special delay box applied to the pulse-per-second signal of the GPS simulator in accordance with PTTI message (that is, time figure of merit), enables such a simulated accuracy.
A standard IS 153-like interface was developed to display GPS data on a convenient GUI in order to have a common software to visualize output data from the GPS receivers. The user can also visualize some specific data from GPS ICDs concerning integrity, alarms, and cryptography.
All receiver output data are recorded for later analysis.
Table 1. Example of Direct P(Y) acquisitions in accordance with time uncertainty (with times to get “GRAM state 5” and “protected status”).
Monte Carlo Trials
The bench enables sequentially and automatically chaining scenarios (up to 10 000 test sequences) to perform statistics on acquisition times. Indeed, it is primarily used for the characterization of TTFF. GPS signal acquisition is dependent on many different parameters, as described in Figure 12. To properly characterize receiver acquisition times requires a large number of tests. The comparison with GPS Receiver Applications Module requirements can be easily performed.
Figure 12. Setup parameters to study GPS signal acquisition.Figure 13. Example of a random selection for the position error.
One Monte Carlo trial consists of a repetition of unitary test: powering the receiver, then sending to the GPS receiver random errors of position, speed, time, levels of jamming, and finally stopping the test sequence on trigger. At the end of Monte Carlo trials, statistical computing enables accurate analysis and expertises.
The random selections are optimized to reduce the number of cases. The bench can replay a particular case: as the seeds are deterministic, a special case of Monte Carlo method can be selected and replayed.
Real-Time INS/GPS Data Fusion
The information delivered by INS and GPS are processed by a Kalman filter. The INS trajectory is provided by the simulator or by an external file.
Two types of coupling are considered: loose coupling with position and velocity information, and tight coupling with pseudoranges and delta ranges to estimate errors. In both cases, the GPS receiver receives aiding from either the simulated INS or the optimal navigation (Kalman filter output).
Figure 14. Example of an optimal navigation along a specified trajectory in a jamming environment.Figure 15. Position and velocity errors and navigation corridor.
The purpose of the Kalman filter is to estimate the navigation errors (position, velocity, and attitudes) and sensor errors (INS, GPS).
The filter design is original because it is independent from the receiver under test and from the type of application (hardiness privileged with reference to jamming). It is also able to estimate the time offset between position and velocity measurement on any GPS receiver under test.
Conclusion
SINERGHYS combines several resources into a single test bench. A complex mode can simulate an operational implementation with different interfaces and by chaining test sequences: receiver initialization, management of the switching of antenna patterns during a simulation, masking of GPS signals, management of jamming, INS/GPS data fusion, and so on. In this mode, missions can be replayed in a realistic environment. This bench is a complementary resource for flight trials and digital models because it can characterize the initialization phases with a good control of initial conditions. SINERGHYS enables users to know, as precisely as possible, the capabilities and limitations of a specific global navigation chain.
Manufacturers
SINERGHYS was developed by Bertin Technologies and specified by the French Ministry of Defense (MoD)DGA Information Superiority. It drives a Spirent GPS/Galileo simulator, Agilent 4431B and MXG generators, and software programs such as Analytical Graphics, Inc. (AGI) Satellite Tool Kit and Ergospace 3D scenes. The embedded jammer was developed by Ineo Defense in 2010 to MoD-DGA specifications.
Stéphane Gallot works at the French MoD (DGA Information Superiority) as a radionavigation expert. His particular interest is the integration of military GPS receivers including SAASM modules within French platforms.
Pascal Dutot is an architect engineer at the French MoD (DGA Information Superiority). His main activity is to optimize and control GPS integration in the global navigation chain.
Christophe Sajous works at the French MoD (DGA Information Superiority) as a radionavigation expert. He is also responsible for the “navigation per satellites” laboratory within the radionavigation department.
This year’s GPS Partnership Council provided among other highlights a discussion of the tensions between commercial off-the-shelf (COTS) receiver systems used in tactical combat operations versus official military GPS user equipment (MGUE), and an enthralling warfighters’ panel that revealed much of those COTS/MGUE dilemmas. The event, held May 1–2 in El Segundo, California, drew an enthusiastic and involved audience, including many GPS veterans. I was struck by the graying of the clan as well as the practiced and confident presentations of current civilian and military program staffs.
