Rolls-Royce and VTT’s vision of futuristic land-based control center, known as the Future Operator Experience Concept or oX. (Concept: Rolls-Royce)
Rolls-Royce and VTT Technical Research Centre of Finland Ltd. have signed a strategic partnership to design, test and validate the first generation of remote and autonomous ships.
The partnership, established in November 2016, combines and integrates the two company’s expertise to make such vessels a commercial reality.
Rolls-Royce is pioneering the development of remote controlled and autonomous ships and believes a remote controlled ship will be in commercial use by the end of the decade. The company is applying technology, skills and experience from across its businesses to this development.
VTT is an expert in ship simulation and the development and management of safety-critical and complex systems in demanding environments such as nuclear safety. It combines physical tests, such as model and tank testing, with digital technologies, such as data analytics and computer visualization.
They will also use field research to incorporate human factors into safe ship design. As a result of working with the Finnish telecommunications sector, VTT has extensive experience of working with 5G mobile phone technology and wi-fi mesh networks. VTT has the first 5G test network in Finland.
Working with VTT will allow Rolls-Royce to assess the performance of remote and autonomous designs through the use of both traditional model tank tests and digital simulation, allowing the company to develop functional, safe and reliable prototypes.
Two remote-controlled ship prepare to pass. (Artist’s concept: Rolls-Royce)
“Remotely operated ships are a key development project for Rolls-Royce Marine, and VTT is a reliable and innovative partner for the development of a smart ship concept,” says Karno Tenovuo, vice president of ship intelligence for Rolls-Royce. “This collaboration is a natural continuation of the earlier user experience for complex systems (UXUS) project, where we developed totally new bridge and remote control systems for shipping.”
“Rolls-Royce is a pioneer in remotely controlled and autonomous shipping. Our collaboration strengthens the way we can integrate and leverage VTT’s expertise in simulation and safety validation, including the industrial Internet of Things, to develop new products and in the future, enable us to develop new solutions for new areas of application as well,” says Erja Turunen, executive vice president for VTT.
Ship Intelligence will make greater use of ship systems and sensors to enhance both crew and vessel operating efficiency. (Rolls-Royce)
A region in France is working with SNCF (the French National Railway Company) to foster the emergence of new solutions — including GNSS technologies — for the operation and control of regional trains and railway infrastructure.
On Sept. 1, the Occitanie/Pyrénées-Méditerranée Region and GUIDE (GNSS Testing Laboratory) signed an agreement to open a railway line to field tests for companies seeking to perform assessments aboard trains. The agreement is supported by the French space agency CNES and the Aerospace Valley Center.
The Geofer project, managed by GUIDE, will allow the testing of applications in operational situations. The applications are based on radionavigation and telecommunication data initially intended for other business sectors.
Through the Geofer project, the Occitanie/Pyrénées-Méditerranée Region is pursuing two strategic goals. The first aims to strengthen mobility within the region through better control of operating costs. The second is to diversify industrial activities with rail. The project could lead to modernization of secondary lines of the national railway network by embedding, for example, some functions of railway signaling.
The test region — the Tessonnières-Rodez line (Tarn/Aveyron) — crosses a mountainous area conducive to tests in constrained environments.
As leader of the project, GUIDE is working to geo-reference the line and to instrument a train that will calibrate future embedded applications. The collected data will then be re-used and replayed on test benches to help solution developers tune their embedded systems more easily.
A co-financer of Geofer, CNES is actively involved in the tests. A receiver implementing an algorithm (PPP-WIZARD) developed by its engineers will be tested on board, using software to exploit future satellite services to achieve decimetric accuracy. This technology could make possible many rail applications such as precise dock stops or a better prediction of maintenance operations.
M3 Systems will supply the mission receiver responsible for dispatching accurate and real-time data about the positioning and speed of the train to embedded applications. This device merges the satellite measurements with those of other sensors used to ensure the quality of the geolocation messages.
For example, devices such as shock sensors to detect unusual efforts of the pantograph against the overhead cable, speed control systems for eco-driving, and roaming systems for telecommunication will be developed, implemented and evaluated on the line and on simulation benches.
The untethered 3D dead-reckoning GNSS module NEO-M8U by u-blox is at the core of Navilock’s new GNSS receiver series for service vehicles. The new portfolio will enable retrofitting of dead-reckoning and untethered dead-reckoning (UDR) technology in any vehicle.
Photo: Navilock
Combining multi-GNSS (GPS, GLONASS, BeiDou, Galileo) with an onboard 3D gyro/accelerometer, the untethered dead-reckoning technology improves position accuracy even where GNSS signals are weak or unavailable, such as in urban canyons, tunnels or parking garages. Receivers with a serial MD6 interface can work in an extended voltage range from 5-48 Volt DC.
Applications for Navilock’s new GNSS receiver series include service vehicles from the police, fire departments, emergency physicians, disaster rescue teams and technical aid organizations that require accurate positioning at all times. Operational forces and their control centers must be constantly aware of their location to enable successful completion of any assignment. As a result, physical dangers and even life threats are clearly minimized.
“We have been collaborating for years with u-blox and highly respect the quality and reliability of its products,” says Karsten Reschke, Navilock product manager. “Particularly critical for our product range is the UDR technology that enables reliable and accurate location capability even without satellite navigation signals.”
“We are pleased to be associated with the Navilock brand and the quality and design reliability it represents,” says Andrew Miles, u-blox product manager. “The ease of use and robust packaging of these products perfectly enable the value of UDR in its target applications.”
Launched in 2016, the u-blox NEO-M8U enables reliable positioning even in case of GNSS signal interruptions, jamming, reflected or weak signals, and is independent of any connection to the car, other than power.
The eight new Navilock GNSS receivers will be available in Q1 2017.
A controlled radiation-pattern antenna can preserve GNSS positioning while providing at least an azimuth angle towards an interference source. If integrated with an attitude and heading reference system (AHRS), only a few lines of position pointing towards the RFI source could provide a fast indication of the probable ground location.
By Gerhard E. Berz, Pascal Barret, Brent Disselkoen, Michael Richard, Vincent Rocchia, Florence Jacolot, Todd Bigham and Okko F. Bleeker
GNSS is an essential enabler for many aviation applications that rely on either accurate position or time synchronization. While the idea of “sole means” GNSS is disappearing, it remains challenging to match the performance and coverage of GNSS with terrestrial systems. This is why aviation is working on Alternate Positioning, Navigation and Time (A-PNT) to cope with the potential for a wide-area GNSS outage. Current navigation aids are clearly part of this approach in the short term. We will continue to need a terrestrial capability for some time, but we don’t expect that it will support the same level of performance as GNSS. Even if we have back-up, we must be able to resolve GNSS outages efficiently.
Among principal GNSS vulnerabilities — constellation performance issues, space/solar weather and radio-frequency interference (RFI) — RFI is the one where observability on the ground is often limited. While the protection of radio services from interference is a state responsibility typically assigned to a telecommunications or other government agency, it is in the interest of an air navigation service provider (ANSP) to be able to request help and enforcement action from the telecommunications regulator in an efficient manner.
As a part of its contribution to Single European Sky ATM Research (SESAR, a collaborative project to improve European airspace and its air traffic management), Eurocontrol has developed an RFI Mitigation Plan as a guidance framework with the objective to maintain risks to GNSS and the associated operations at tolerable levels. The document will be published by ICAO in its GNSS Manual in the new 2017 edition.
MITIGATION PLAN
RFI can be a security issue. Consequently, a commonly used philosophy in the security domain was used in the mitigation plan: there are many potential threats, but not necessarily all of them translate into operationally relevant risks. Threats are thus sort of dormant risks, which, if left to develop unmitigated, could develop into risks to aviation. The mitigation process monitors threats, assesses risks, and then implements suitable mitigation to stop threats from developing into risks. Three successive stages have been identified where such barriers can be applied:
Prevent transmission of RFI, mostly through radio regulatory actions and coordination;
Prevent interruption of positioning and navigation capabilities in the presence of RFI. This is achieved at the avionics level by making sure receivers can tolerate some RFI as well as redundant capabilities;
If interruption cannot be avoided, ensure that other communication, navigation and surveillance capabilities provide continued safety while being able to detect, locate and eliminate an RFI source efficiently.
This third barrier is where flight inspection or other aerial work platforms can play a significant role. However, this role is not limited to risk mitigation. Aerial measurement capabilities can also play a role in threat monitoring by getting data on RFI emissions that are too weak to pose operational risks, and facilitate risk assessment by providing a reliable reference of the impact of such signals on an aircraft in flight.
FLIGHT INSPECTION
Similar to the subject of flight validation, airborne GNSS signal-in-space testing must not necessarily rely on traditional flight inspection capabilities. Other aerial work capabilities can be used, and it is hoped that, over time, data from regular aircraft operations and event recording systems can be used at least for threat-monitoring purposes. However, as soon as a significant RFI occurs, purpose-built aerial detection and localization capabilities are hard to beat. Given that aviation is carrying the risks related to RFI, and telecom regulators are unlikely to have such capabilities, this naturally points to the experience and resources of flight inspection aircraft and their crews.
Even if a significant amount of ground-based RFI sensors are available, local building shadowing can make it difficult to impossible to detect and locate an RFI emitter. Aircraft-provided data can be superior to ground data, and a rough aircraft-based localization can greatly increase efficiency of ground-based localization and source elimination efforts. Aerial RFI localization capabilities offer unique strengths in an overall cooperative process.
EVOLVING SIGNALS
GNSS manifests the transition from analog signals of conventional navigation aids to digital ones. A common characteristic of digital signals is their better use of a frequency channel by spreading the carrier energy such that distinct carrier or subcarrier tones become difficult to observe. Unfortunately, RFI sources have kept up with this, and now most commonly employ swept CW signals, easy to produce but still looking essentially like broadband signals. Many unintentional RFI sources also look like broadband.
Because GNSS is a multi-modal system not uniquely used by aviation, a new type of RFI threat is becoming more common: intentional RFI, which is not directed at aviation, but may nonetheless have an impact. Because there is no direct intent to harm aviation, the nature of these signals and RFI scenarios can become diverse and unpredictable. Furthermore, given the prevalent and ubiquitous nature of GNSS, the number of potential RFI threats is more significant and will evolve more dynamically than aviation capabilities.
A recent effort collecting GPS outage data reported by pilots revealed that a small but surprising number of outages that could potentially be linked to RFI occur on a regular basis, even during en-route operations in some limited regions of the world. For flight inspection, this implies it would be useful to increase the sensitivity of RFI source detection commensurate with the digital nature of GNSS and consistent with the power levels that can impact receivers.
Another particular challenge comes from the specification of an interference mask for GNSS. Other navigation systems do not have such a mask, or any kind of minimum signal-to-noise ratio standard. The mask represents a realistically achievable interference environment. It has been adopted as a global benchmark where receivers experiencing signals above the mask may not produce misleading information, but may stop operating.
However, in practice, little is known about by how much typical receivers exceed the minimum masks. Some tests have reported a margin as significant as 23 dB to CW and 10 dB to broadband signals. This means that an RFI which may not bother one type of receiver at all could be a significant problem for another, limiting the possibility to rely on observed receiver performance. It also implies that signal-in-space effects should be detectable at the low levels of the ICAO receiver RFI mask.
CRPA LOCALIZATION
For civil aviation as opposed to military operations, a CRPA could make sense provided that it outperforms current RFI localization methods at a reasonable price. In military applications, the exact location of the RFI source may be of a secondary nature, as long as desired signal tracking can be maintained.
However, by steering a null (negative gain) towards the angle of arrival of an undesired signal source, a line or sector of possible source positions can be obtained. In this case, the main objective would not be to null a deliberate interferer or jammer, but to obtain a bearing on the type of the interferer. The main scenario we worry about that leads to low-power events are those where aviation is not the desired target, such as a PPD. Unintentional cases can be a mix of high- or low-power cases. The use of a GNSS-specific antenna is expected to provide the required sensitivity, while being able to profit from the military off-the-shelf development. When further integrated with standard flight-inspection sensors such as an attitude and heading reference system (AHRS) and additional geolocation software, this approach has the potential to increase the reliability, accuracy and speed of geolocation while reducing operator effort and flying time. An additional potential benefit is the preservation of ownship position when flying into an area of significant RFI.
The suggested use of military technology brings with it the question on how such use could be authorized. CRPA antennas and associated antenna electronics manufactured in the United States fall under the International Traffic in Arms Regulation (ITAR). While this is a solvable but, nonetheless, cumbersome issue, the approach taken by this project was first to evaluate possible benefits from using a CRPA before worrying about the ITAR issue.
This study was conducted by Eurocontrol in the frame of a SESAR Project on GNSS, including a contract with Rockwell Collins for a feasibility study of the CRPA RFI localization concept. The French (DSNA/DTI) and U.S. FAA Flight Inspection service supported the project with expertise and in-kind contributions. The FAA conducted an overflight with a direction-finding-equipped aircraft for direct comparison between the CRPA approach and other, non-GNSS specific, commercial solutions.
TECHNOLOGY OPTIONS
Current, common GNSS CRPAs come in either 4- or 7-element variants. CRPAs always require antenna electronics for further processing of the RF inputs, and perform either nulling (steering negative gain towards RFI sources) or beamforming (steering positive gain towards GNSS satellites), or both. The most performant system is a 7-element CRPA in combination with digital beam-former antenna electronics. The 7-element CRPA has a diameter of 36 cm (14 inches), which is of some concern for installation on a typical flight-inspection aircraft such as the Beech King Air. But for a feasibility study, it makes sense to first evaluate the most-performing option. If there is unnecessary margin, the solution can be simplified afterwards.
A top-mounted solution on the airplane fuselage was retained due to experience with military anti-jam performance suggesting that RFI localization performance would be sufficient while retaining the benefit of stable ownship position. A key element of the assessment focused on how to best use aircraft banking to facilitate geo-localization.
As shown in Figure 1, the CRPA is connected to the Digital Integrated GPS Anti-Jam Receiver (DIGAR). As there is one RF cable per CRPA element, it is useful to install the DIGAR as close as possible to the CRPA. The standard military-production DIGAR contains not only the antenna electronics but also the receiver including baseband processing. For civil purposes, either a civil receiver would need to be integrated into the DIGAR or, alternatively, a single RF output is available to connect a standard civil GPS receiver. The DIGAR will also feed angle-of-arrival information into a direction-finder software.
Figure 1. System configuration. Source By Gerhard E. Berz, Pascal Barret, Brent Disselkoen, Michael Richard, Vincent Rocchia, Florence Jacolot, Todd Bigham and Okko F. Bleeker
The software provides angle-of-arrival information with respect to the antenna/aircraft reference frame. To provide a geolocation capability, this must be combined with ownship position and aircraft attitude. As most flight inspection aircraft are equipped with an AHRS, this is not expected to be a problem. Project resources did not permit full integration, so testing was done using the direction-finder display only. The AHRS would need to provide 10–50 Hz updates with an error of not more than ±2 degrees.
Figure 2 shows an example of the direction-finder output. Lighter areas show where the antenna electronics produce negative gain, while darker areas represent stronger positive gain. The red dot indicates a potential interferer has been identified. Source location is at about 280 degrees of azimuth with respect to aircraft nose.
Figure 2. Excerpt from direction finder polar display of RFI signal angle of arrival. Source By Gerhard E. Berz, Pascal Barret, Brent Disselkoen, Michael Richard, Vincent Rocchia, Florence Jacolot, Todd Bigham and Okko F. Bleeker
Correct detection probability will depend on the sensitivity threshold and associated false detection probability being considered acceptable. A visual localization may still be possible at carrier-to-noise density ratios (C/N0) below those needed to produce the red dot here, especially if the visible ambiguity can be removed through some aircraft maneuvering. It can be inferred from the system description that once the full integration is accomplished, the provision of a direct output using only a few lines of position to find a probable RFI source location in terms of approximate lat/long coordinates should be straightforward.
SIMULATOR TESTING
A well-calibrated simulator capable of feeding the seven RF inputs was used to assess detection performance for different flight patterns near an RFI source. The tested patterns include a rectangular, a circular and an oscillating, S-shaped trigger-and-hunt trajectory. A variety of different encounter scenarios in terms of power levels and free space path loss were tested. Power levels were adjusted to produce a 1-dB reduction in the C/N0. Both a continuous wave (CW) interferer at the L1 center frequency and a broadband (BB) interferer were simulated (using a 20-MHz-wide PSK signal). Figure 3 shows an example of achieved detection accuracies in both azimuth and elevation angle.
Figure 3. Example result of angular detection performance. Source By Gerhard E. Berz, Pascal Barret, Brent Disselkoen, Michael Richard, Vincent Rocchia, Florence Jacolot, Todd Bigham and Okko F. Bleeker
While there is a strong peak within ±10 degrees of azimuth, there are also significant outliers. For the elevation (note the normalized scale), however, the main peak is thinner with even stronger sidelobes. Due to the installation of the antenna on top of the aircraft fuselage, the simulation results indicate that the elevation angle output is not very useful for detection. The time series result for the azimuth is given in Figure 4, where it can be seen that there are many good detection matches but also some “sympathetic nulls” that move in the opposite direction of the ground track truth reference (circled in grey). It is expected that with additional software processing, these sympathetic nulls can be filtered out.
Figure 4. Azimuth Time Series Result Corresponding to Figure 3. Source By Gerhard E. Berz, Pascal Barret, Brent Disselkoen, Michael Richard, Vincent Rocchia, Florence Jacolot, Todd Bigham and Okko F. Bleeker
For all tested scenarios (assuming additional filtering), azimuth detection capability was better than ±10 degrees (one standard deviation), and in some cases as accurate as ±2 degrees. There was no significant difference between CW and BB results. As could be expected, simulated aircraft banking significantly improved detection capability. Consequently, the use of orbits seems to be the best search strategy. The simulator testing used a figure-eight pattern with one of the orbits passing over the interference source.
LIVE-SKY VAN TESTING
Rockwell Collins has an authorization to broadcast RFI test signals at the GNSS L2 frequency. Previous work showed that the results at L2 can be applied equally to L1. Figure 5 shows the test area, including a –100-dBm signal level boundary. The interferer was installed on a tripod and fed by a signal generator using a normal GPS fixed radiation pattern antenna (FRPA).
Figure 5. Live-sky test area. Source By Gerhard E. Berz, Pascal Barret, Brent Disselkoen, Michael Richard, Vincent Rocchia, Florence Jacolot, Todd Bigham and Okko F. Bleeker
Locations B and C were used to both calibrate the RFI level and as check points for the van trajectory. The test van included a fixture that allowed a tilting of the CRPA by 30 degrees from zenith to either side. Figure 6 shows a schematic of the tilt fixture. It can be seen that this set up creates a realistic RFI path that arrives with an elevation slightly below the horizon at the unit under test. Two sets of tests were performed: one where the van drove straight into or out of the area of interference to determine overall equipment sensitivity, and varied paths to quantify angular detection performance. Again, both CW and BB RFI signals were evaluated.
Figure 6. CRPA with tilt fixture. Source By Gerhard E. Berz, Pascal Barret, Brent Disselkoen, Michael Richard, Vincent Rocchia, Florence Jacolot, Todd Bigham and Okko F. Bleeker
Not surprisingly, elevation angle results turned out not to be very reliable given the below horizon signal path. But azimuth errors were slightly greater than obtained during the wavefront simulator testing (±12 degrees, one sigma). This can be attributed to both multipath and a less accurate heading truth reference. Taking these additional factors into account, the results are very consistent. Tilting the antenna by 30 degrees towards the RFI source significantly improves azimuth resolution (to about ±8 degrees) while also reducing sympathetic nulls. When the tilted antenna points away from the RFI source path, azimuth accuracy will decrease, which is considered helpful in avoiding false detections.
Summary. Even if a good bit of integration work remains necessary to produce a production-ready system for flight inspection or other similar aircraft, the approach shows promise. Further testing, especially using an actual aircraft installation, is recommended. Installation of a 7-element CRPA will be challenging on a typical Beech King Air, but possible. Antenna calibration requirements are expected to be manageable with a standard network analyzer. To avoid further complications with export regulations, the use of a separate civil GNSS receiver is recommended. The overall system is, at this stage, still on the costly side.
While a 4-element CRPA could be used, this was estimated to double or triple angular azimuth detection errors and reduce the detection distance, and consequently not likely to be worth the additional cost. While smaller 7-element CRPAs than the one used are available, their performance would need to be assessed.
For a top-mounted CRPA, aircraft banking is essential to ensure good performance. This could increase the amount of airspace required for detection and lead to operational complications. Furthermore, since the aim is to increase detection sensitivity to geo-locate weak power sources such as personal privacy devices, maintaining ownship position is not that critical, as it can be managed by maintaining an appropriate distance from the RFI source if needed. Consequently, both DSNA and FAA recommend using a bottom-mounted CRPA. In addition to adding 10 dB of detection sensitivity on average and reducing the need for maneuvering, it may restore the utility of the elevation output, thereby potentially further reducing search time. Either way, it will be useful for equipped aircraft to have alternate positioning capabilities to GNSS both for aircraft guidance and truth reference systems.
The system required a 15-dB stronger signal to transition from detection to localization. However, this is dependent on the accepted false-alarm rate. A tunable procedure can be envisaged where the software accepts a higher false-alarm rate at first to maximize search capability and moving to a lower alarm rate to confirm suspected RFI source locations later. Both the potential of the additional filtering software and any human-machine interface aspects would need to be further evaluated.
GENERIC CAPABILITIES
The two common options for in-flight detection of RFI sources in any relevant frequency band are the use of either a spectrum analyzer or, if available, a direction finder. The spectrum analyzer approach depends on connection to a suitable antenna, preferably with some directionality. In this way, the aircraft can be maneuvered to point the antenna either towards or away from the RFI source. Normally there is very little directivity, making this a challenging search. A direction finder is a significant improvement. Figure 7 shows the L-band antenna array used by a DF-4400 as installed on the bottom of the aircraft.
Figure 7. CRPA with tilt fixture. Source By Gerhard E. Berz, Pascal Barret, Brent Disselkoen, Michael Richard, Vincent Rocchia, Florence Jacolot, Todd Bigham and Okko F. Bleeker
Newer generation spectrum analyzers with a good GNSS-specific pre-amplifier, using digital sampling with a fast A/D converter, could provide useful capability. However, the subject is beyond the scope of this discussion, and we focus here on comparing the CRPA approach with a standard direction finder.
The FAA Flight Inspection service conducted complementary flights during the Rockwell Collins live-sky van testing. The flights included orbits and a direct overflight of the RFI source. This was complemented by additional laboratory calibration to ensure that results could be compared. The sensitivity results of the CRPA approach are more meaningful in comparison with a generic direction-finder capability. Since test data is only available for a top-mounted CRPA, the comparisons here are made for the preferred bottom-mounted CRPA using engineering estimation.
The key finding was that while direction-finding capability was quite comparable between the CRPA- system and the DF-4400 for CW, the CRPA-system outperforms the DF-4400 by a significant margin when encountering broadband signals. This is considered to be a significant improvement given the expected nature of RFI sources. During the FAA overflight, the aircraft did not manage to detect the broadband signal. Consequently, the values given here are reconstructed from laboratory analysis. Table 1 compares the estimated achievable sensitivities.
Table 1. Comparison of direction-finding sensitivity. Source By Gerhard E. Berz, Pascal Barret, Brent Disselkoen, Michael Richard, Vincent Rocchia, Florence Jacolot, Todd Bigham and Okko F. Bleeker
In view of the limitations of the data analysis performed, these values must be interpreted with caution. In general, we can conclude that the direction-finding sensitivity of the CRPA system is relatively insensitive to the encountered modulation of the RFI signal, and that the bottom-mounted CRPA system outperforms the DF-4400 system by a small margin in the CW case and by a large margin in the broadband case. How many additional dBs can be gained by both approaches through further optimizations is for future analysis. The performance improvement of the CRPA system does come at a cost, as could be expected.
DETECTION
Before the search for an RFI source can begin, it must be detected. Normally it should be easier to detect an RFI source than to locate it, since direction-finding requires a certain signal strength to obtain bearing information. However, given the directionality of DF arrays, this may not necessarily be true. Another potential factor is the reliance on a spectrum analyzer to detect RFI, which may not achieve the corresponding noise floor, especially when using a broad scan across a wide frequency range. The direction-finder system needs about a 15-dB difference between detection and localization ability.
Figure 8 shows the detection ranges for the top-mounted CRPA system for a given ground-based emitter while the aircraft altitude is assumed at 2000-ft AGL. The bottom mounted system would improve the minimum detection threshold further. Given that 15 dB can translate into a significant difference in free space path loss distance, concepts for efficient direction finding once an RFI source is detected deserve further attention.
Figure 8. Detection ranges for top-mounted CRPA system. Source By Gerhard E. Berz, Pascal Barret, Brent Disselkoen, Michael Richard, Vincent Rocchia, Florence Jacolot, Todd Bigham and Okko F. Bleeker
HUMAN FACTORS
During the FAA overflight, the broadband RFI couldn’t be detected by either the spectrum analyzer in use or the DF-4400. Part of the challenge was using the right equipment settings. For the DF-4400, it was found that best performance could be obtained for detecting broadband RFI when using the FM wide mode of demodulation. Similar findings were obtained for the use of the spectrum analyzer, where specific skills are necessary to use the equipment to its fullest capability. Similar issues are expected when having to interpret the display of a CRPA-based system. This means that regardless of the RFI source geo-location approach used, specific training should ensure that aircraft operators have the greatest chance of success in finding RFI sources.
CONCLUSIONS
An approach using a CRPA antenna, electronics and processing software proved superior to current, generic direction-finding capabilities, especially with respect to broadband signals. Maintaining ownship position in the presence of RFI is a secondary objective when looking for the expected weak signal sources, and the use of a bottom-mounted CRPA system is preferred. Additional filtering to eliminate sympathetic nulls and other issues require further investigation.
Significant benefit derives from employing aerial work aircraft in cooperation with ground-based capabilities. We recommend that equipment manufacturers further study all aspects of GNSS RFI geo-location and improve their capabilities. Such capabilities are expected to limit the exposure time to RFI cases and allow a more efficient deployment of ground-based spectrum enforcement resources. These studies should include the improvement of detection and localization equipment, and the development of corresponding operational procedures for flight crews.
ACKNOWLEDGMENTS
The Eurocontrol-funded contract with Rockwell Collins is part of the Eurocontrol contribution to SESAR Project 15.3.4, GNSS Baseline and the GNSS RFI Vulnerability Mitigation Task.
Rockwell Collins provided the DIGAR and Direction Finder Software.
This article is based on a paper presented at ION-GNSS+ 2016.
Disclaimer. This article does not contain any official Eurocontrol, SESAR, FAA or DSNA position or policy. It does not constitute any endorsement of a particular product, or a statement of any kind relating to any future procurement activity.
GERHARD BERZ and PASCAL BARRET work at Eurocontrol, Belgium; VINCENT ROCCHIA and FLORENCE JACOLOT with Direction des Services de la Navigation Aerienne, France; BRENT DISSELKOEN and MICHAEL RICHARD at Rockwell Colins, U.S; Okko F. Bleeker with OFBConsult System Engineering, the Netherlands; and TODD BINGHAM with the U.S. Federal Aviation Administration.
Spireon Inc., an aftermarket telematics company for risk management and business optimization, will introduce its latest connected car solution, Kahu.
Photo: Kahu
Kahu is designed for dealers, providing streamlined lot management while delivering a new finance and insurance (F&I) profit center by offering consumers a modern location tracking and stolen vehicle recovery service, Spireon said.
Additionally, Kahu empowers dealers to grow service retention with car buyers by providing accurate vehicle data for proactive maintenance reminders that can improve vehicle health and keep vehicles within warranty.
“New car dealer margins have been flat for several years, driving a need to create new revenue and profit opportunities,” said Kevin Weiss, CEO at Spireon. “Connected cars are changing the industry, but dealers are receiving little value from this shift. Kahu changes that dynamic, giving dealers the tools they need before, during and after the sale to grow profits and benefit from the connected car revolution.”
Kahu includes an aftermarket GPS device and mobile apps for both dealers and their customers. The solution provides these features and benefits to dealers:
Lot Management — Dealers can manage inventory, track specific vehicle location, and see low-battery indicators using a mobile phone or tablet, streamlining operations and creating a better buying experience for consumers. Virtual geofences and after-hours alerts allow dealers to identify and recover stolen vehicles within minutes.
F&I Profit Center — Kahu offers dealers a high-value add-on for consumers who seek peace of mind with a next-generation vehicle recovery service and an arsenal of easy-to-use mobile features. From 24/7 vehicle location visibility, so consumers can track their vehicle and family at all times, to smart alerts for speeding and low battery, Kahu is an attractive add-on that safeguards consumers while driving dealer profit.
Customer Loyalty — Kahu uses GPS-based mileage tracking to improve the accuracy of service reminders and increase service retention. Consumers benefit by being able to maximize warranty protection and ensure recommended service intervals are maintained.
“Our partnership with Spireon has paid for itself tenfold,” said Jon Hansen, general sales manager, Burien Nissan. “Being able to offer a product that I find value in to our customers and making it a revenue generator for the dealership is really big for us. I would absolutely recommend Spireon to other dealerships.”
Spireon’s aftermarket GPS devices are installed on more than 3.5 million vehicles and offered by 14,000 dealerships across North America. With Kahu, car dealers and consumers now have access to state-of-the-art mobile location services, which protect their vehicle assets and can lead to reduced insurance premiums.
Kahu is already installed with a select group of early adopter customers, and will be generally available in the second quarter of 2017.
The change provides a secure, encrypted connection between browsers or other tools connecting to the Navigation Center website. It also provides authentication that you are unquestionably connecting to the Navigation Center website.
This change is a result of Office of Management and Budget (OMB) Memorandum M-15-13, Policy to Require Secure Connections across Federal Websites and Web Services, which requires that all publicly accessible federal websites and web services only provide service through a secure connection (HTTPS instead of HTTP).
Address any questions to the Navigation Center’s Web Services team via the Contact Us page.
Caltrans — the California state agency responsible for highway, bridge and rail transportation planning, construction and maintenance — has taken delivery of the new Riegl VMX-1HA mobile mapping system.
The Riegl VMX-1HA dual-scanner mobile mapping system. Photo: Caltrans
The Riegl VMX-1HA is a high-speed, high-performance dual-scanner mobile mapping system. It provides high performance and dense, accurate and feature-rich data at highway speeds.
With two million measurements and five hundred scan lines per second, the turnkey solution is suited for survey-grade mobile mapping applications to meet the standards of departments of transportation nationwide, Riegl said.
The technology of the system comprises two Riegl VUX-1HA high-accuracy waveform lidar sensors and a high-performance INS/GNSS unit, housed in an aerodynamically shaped protective cover. Four 9-megapixel cameras, along with a LadyBug 5 camera, complement the waveform lidar data with precisely georeferenced images.
The Riegl software suite provides seamless workflows for mobile data acquisition, processing, adjustments and deliverables.
Riegl USA was awarded the contract of the Request For Quote (RFQ) on the open market.
The government of India has warned domestic airlines of “consequences” if they do not use GAGAN, the state’s GPS-Aided Geo Augmented Navigation system, reports the Mumbai Mirror.
The warning came during a meeting called by the Directorate General of Civil Aviation (DGCA) in December with all stakeholders, including the airlines. Most aircraft registered in India are still not equipped with the technology two years after its launch.
While smaller aircraft such as ATRs and Bombardiers in the Indian carriers’ fleet are already equipped with the GAGAN system, bigger planes need to be retrofitted at the airlines’ expense, including Airbus A320, A330, Boeing 737, B777 and B 787. Eight major domestic carriers — Air India, Air India Express, Jet Airways, JetLite, IndiGo, SpiceJet, GoAir, Vistara and AirAsia — have 427 such planes in service, Mumbai Mirror reports.
The National Civil Aviation Policy, announced by the government in June, makes it mandatory for all aircraft registered in India to be GAGAN-enabled by Jan. 1, 2019.
Jointly developed by Indian Space Research Organisation (ISRO) and Airports Authority of India (AAI), the GAGAN system was officially launched by Civil Aviation Minister Ashok Gajapathi Raju in July 2016. It is said to make airline operations more efficient and cut down costs as it reduces separation between aircraft, increases air safety and fuel efficiency.
GAGAN’s footprint extends from Africa to Australia and has expansion capability for seamless navigation services across the region. The system is inter-operable with other international satellite based tracking systems such as the WAAS (US), EGNOS (Europe) and MSAD (Japan).
Iridium Communications Inc. has successfully launched its first 10 Iridium NEXT satellites, which will support real-time automatic dependent surveillance broadcast (ADS-B) operations in oceanic regions.
Iridium NEXT is the company’s next-generation satellite constellation, replacing and enhancing its existing network of low-Earth orbit satellites spanning the entire globe — the largest commercial satellite constellation in space.
A SpaceX Falcon 9 rocket lifts off from Space Launch Complex 4E at Vandenberg Air Force Base, California, Jan. 14. (Photo: SpaceX)
The satellites were delivered into low-Earth orbit an hour after a SpaceX Falcon 9 rocket lifted off from Vandenberg Air Force Base in California at 9:54:39 a.m. PST on Jan. 14.
The launch is the start of a series of Iridium NEXT launches scheduled over the next 18 months, and marks the beginning of one of the biggest “tech refreshes” in history, completely replacing the only satellite constellation providing 100-percent global communications coverage.
Once fully deployed, Iridium NEXT will enable a new broadband multi-service capability called Iridium CertusSM, while providing the technical flexibility to support innovative new services and technologies from Iridium’s extensive partner network.
Aircraft surveillance
Among those technologies is a unique hosted payload from Iridium’s partner Aireon, which will provide a real-time global aircraft surveillance service, extending aircraft visibility across the planet.
Aireon’s space-based ADS-B receiver network will relay signals from all ADS-B equipped aircraft to controllers worldwide, allowing 100 pecent global air traffic surveillance. (Image: Aireon)
According to Aireon, its space-based ADS-B network will transform air traffic management capabilities, providing air traffic surveillance and flight tracking across 100 percent of the planet. Currently, more than 70 percent of the earth, including oceanic and remote airspace, has no existing air traffic surveillance.
The first 10 Iridium NEXT satellites were delivered to a 625 kilometer (km) temporary parking orbit where they will be tested and exercised by Iridium over the coming weeks. Upon meeting testing and validation requirements, the satellites will then be moved into their 780-km operational orbit and begin providing service to Iridium’s customers.
As part of this testing and validation process, Aireon’s ADS-B receivers, which were manufactured by Harris Corporation, will provide air traffic surveillance data through the Aireon network to the Service Delivery Points (SDPs) at partners NAV CANADA, NATS, ENAV, the Irish Aviation Authority (IAA), as well as the Federal Aviation Administration (FAA) William J. Hughes Technical Center in Atlantic City, New Jersey.
One by one, the new satellites will be positioned near a current generation satellite, each moving at approximately 17,000 miles per hour as testing begins. Iridium’s inter-satellite communication links from nearby satellites will be repositioned to point to the new Iridium NEXT satellite as it prepares to take over service. Existing satellites will eventually be de-boosted and de-orbited.
“Today Iridium launches a new era in the history of our company and a new era in space as we start to deliver the next-generation of satellite communications,” said Matt Desch, chief executive officer of Iridium. “We have been working endless hours for the last eight years to get to this day, and to finally be here with ten Iridium NEXT satellites successfully launched into low-Earth orbit is a fulfilling moment. We are incredibly thankful for all of the hard work from our team, as well as our partners, to help us achieve this milestone.”
Both Thales Alenia Space, System Prime Contractor for the program, and their subcontractor for production, Orbital ATK, have been integral in the development of the Iridium NEXT program, from the design and manufacturing of the Iridium NEXT satellite vehicles to managing an 18-station, state-of-the-art assembly line production system.
“Leading a worldwide team to manufacture, assemble, test and prepare each satellite for this moment has been incredibly exciting,” said Bertrand Maureau, executive vice president of telecommunications at Thales Alenia Space. “We are very proud to have conducted such a unique program, in terms of scale and complexity as well as to have successfully completed the end-to-end whole constellation on-ground validation. The system is fully tested, and the compatibility of Iridium NEXT with the Block-1 operating satellites has been perfectly demonstrated. It has truly been an honor, and we are looking forward to completing the rest of the Iridium NEXT constellation through 2017 and early 2018.”
“We are proud to be a part of this revolutionary satellite program,” said Frank Culbertson, president of Orbital ATK’s Space Systems Group. “Seeing these first ten satellites launch successfully into space is the result of a unique assembly-line process at our satellite manufacturing facility that represents a remarkable achievement. We look forward to seeing the innovative solutions these satellites, which are great examples of leading-edge technology and manufacturability, will enable.”
In addition to partnering with Thales Alenia Space as System Prime Contractor, Iridium has partnered with SpaceX for the launch of 70 Iridium NEXT satellites on its Falcon 9 rocket.
“We are very proud to be chosen as the launch provider for the entire Iridium NEXT program and are excited about today’s successful first launch,” said Gwynne Shotwell, President of SpaceX. “Iridium was one of SpaceX’s first customers, and working alongside them to deliver one of the largest aerospace projects underway is an exciting moment for us at SpaceX.”
Iridium and SpaceX are partnered for a series of seven launches, deploying ten Iridium NEXT satellites at a time. The next major milestone will be the completion of on-orbit testing of these satellites, to validate performance requirements are met.
The second Iridium NEXT launch will be scheduled after testing is completed in April. The entire Iridium NEXT network is scheduled to be completed by mid-2018.
The Australian Government will invest $12 million in a two-year program looking into the future of positioning technology in Australia.
The funding includes testing of satellite-based augmentation systems (SBAS) that can offer instant, accurate and reliable positioning technology. The improvements in positioning could provide future safety, productivity, efficiency and environmental benefits across many industries in Australia, including transport, agriculture, construction and resources.
The two-year project will test SBAS technology that has the potential to improve positioning accuracy in Australia to less than five centimeters. Currently, positioning in Australia is usually accurate to five to 10 meters. While highly accurate positioning technologies are already available in Australia, they are expensive and only available in specific areas and to niche markets.
Research has shown that the widespread adoption of improved positioning technology has the potential to generate upwards of $73 billion of value to Australia by 2030.
Federal Minister for Infrastructure and Transport Darren Chester said the program could test the potential of SBAS technology in the four transport sectors — aviation, maritime, rail and road.
“SBAS utilizes space-based and ground-based infrastructure to improve and augment the accuracy, integrity and availability of basic GNSS signals, such as those currently provided by the USA Global Positioning System (GPS),” Chester said.
“The future use of SBAS technology was strongly supported by the aviation industry to assist in high accuracy GPS-dependent aircraft navigation. Positioning data can also be used in a range of other transport applications including maritime navigation, automated train management systems and in the future, driverless and connected cars,” he said.
Minister for Resources and Northern Australia Matt Canavan said access to more accurate data about the Australian landscape would also help unlock the potential of Northern Australia.
“This technology has potential uses in a range of sectors, including agriculture and mining, which have always played an important role in our economy, and will also be at the heart of future growth in Northern Australia,” Senator Canavan said. “Access to this type of technology can help industry and Government make informed decisions about future investments.”
The SBAS testbed will use existing national GNSS infrastructure developed by AuScope as part of the National Collaborative Research Infrastructure Strategy. It will test two new satellite positioning technologies — next-generation SBAS and Precise Point Positioning, which provide positioning accuracies of several decimeters and five centimeters respectively.
The SBAS testbed is Australia’s first step towards joining countries such as the U.S., Russia, India, Japan and many across Europe in investing in SBAS technology and capitalizing on the link between precise positioning, productivity and innovation.
Early this year, Geoscience Australia with the Collaborative Research Centre for Spatial Information (CRCSI) will call for organizations from a number of industries including agriculture, aviation, construction, mining, maritime, rail, road, spatial and utilities to participate in the testbed.
For more information about the SBAS testbed and National Positioning Infrastructure Capability visit the Geoscience Australia website.
Sonardyne Inc. has supplied acoustically aided inertial navigation technology to McDermott International for its Lay Vessel 108 (LV 108). McDermott is an offshore engineering, procurement, construction and installation company.
The Ranger 2 Pro DP-INS system, the highest specification available from Sonardyne, is being used to support touchdown monitoring surveys of submarine cables, umbilicals and pipelines and as an independent position reference for the LV 108’s Kongsberg dynamic positioning (DP) system.
McDermott’s Lay Vessel 108. Photo: McDermott
McDermott’s LV 108 entered service in 2015 and is on contract in the Ichthys field, Western Australia. Designed as a fast-transit, dynamically positioned (DP 2) vessel for subsea constructions support across a wide variety of water depths, the LV 108 has 21,528 square feet of deck space and can accommodate a crew of 129.
Dynamically positioned construction and installation vessels such as the LV 108, conventionally rely on ultra-short baseline (USBL) acoustics and the GNSS as their primary sources of position reference data.
However, a vessel’s station-keeping capability can be compromised in the event the USBL is affected by thruster aeration and noise and the GNSS signal is simultaneously interrupted. The latter is particularly common around equatorial regions and during periods of high solar radiation.
Sonardyne’s Ranger 2 Pro DP-INS system addresses this operational vulnerability. It aids vessel positioning by exploiting the long-term accuracy of Sonardyne’s Wideband 2 acoustic signal technology with high-integrity, high-update-rate inertial measurements. The resulting navigation output has the ability to ride-through short-term acoustic disruptions and is completely independent from GNSS.
In addition to the system’s deep-water positioning performance and safety benefits, DP-INS has been proven to deliver valuable time and cost savings for vessel owners. It does not need a full seabed array of transponders to be installed and calibrated before subsea operations can commence. For most subsea tasks, positioning specifications can be met with only one or two transponders deployed on the seabed.
Additionally, as the system needs only occasional aiding from the acoustics, transponder battery life is substantially increased and the need to task a remotely operated underwater vehicle (ROV) to deploy and recover transponders for servicing is reduced.
The equipment supplied to McDermott for the LV 108 included Sonardyne’s INS sensor co-located with the company’s sixth-generation (6G) HPT acoustic transceiver. This hardware was installed on one of the vessel’s two Kongsberg through-hull deployment machines and interfaced directly with the vessel’s DP system, also supplied by Kongsberg.
The Dutch state-owned rail company NS Groep N.V. is deploying a real-time remote diagnostics monitoring system. As a core component of NS’ overall real-time monitoring architecture, the system allows railway operators to streamline maintenance costs and provide efficiencies across their fleet by automating manual tasks.
NS in the Netherlands will join a growing number of large rail operators that have implemented GNSS solutions, in this case the Trimble R2M system. Others using R2M include South West Trains in the United Kingdom, Irish Rail, SNCF France, SBB Switzerland and VR Finland.
R2M processes diagnostic data from rail vehicles in real time. It provides a comprehensive view of the overall fleet’s status including specific vehicle faults. The system also identifies potential faults that may arise while analyzing and detecting anomalies in on-vehicle component behavior to identify component issues and the possible impact this behavior may have on the vehicle and overall fleet.
With the R2M software, NS will be able to aggregate data from a range of on-train and wayside sources and provide real-time information to the NS Train Helpdesk to monitor the fleet status. Information will also be available to fleet analysts, work-planning engineers and mechanics to support the operational repair process of NS in real time.
