Charlie Trimble provides the 4000A GPS Locator to the Smithsonian Museum. Introduced in 1984, it was the first commercial GPS positioning product. (Image: Smithsonian)
Trimble Navigation, which had started out making Loran receivers, was looking for its next marine project when HP decided to cancel its GPS project. Budget problems in Washington put completion of GPS in doubt. However, encouraging words from Brad Parkinson were enough for Trimble Navigation to buy the canceled project.
The purchase included a stack 14-ft high of unclassified reading material and a breadboard that fit on the table of a mobile home. It was a working GPS receiver that had recorded the mobile home’s position as it was driven around freeways in the San Francisco area. It took 12 months for a team of two engineers and 15 consultants to come up with the seven breakthroughs needed for the block diagram. Trimble was to iterate this block diagram on an 18-month cycle to follow Moore’s Law cost curve to the $100 required for car navigation. It took another year to build six rack-mounted multichannel receivers.
In October 1984, Trimble sold the first receiver for $100,000. Then came the sale of 20 OEM single channel timing receivers. The oil service industry was an important early market. At the time there were only seven GPS satellites in the sky and applications were limited to 3-4 hrs/day of accurate position measurement. Accuracy was a market driver, which led to the development of differential systems. These provided meter accuracies over wide areas. The next and far more difficult step was enabling a 1st order survey — which required accuracies of 1 cm/km.
Meanwhile, next gen GPS was added to Trimble’s marine Loran-C receiver and the company produced aviation receivers for the commercial markets. In January 1986, Trimble licensed its GPS technology for the Japanese car navigation market to Pioneer.
Then came the Shuttle disaster, and a new rocket had to be designed to launch more satellites. With only seven satellites in the sky and an unknowable time for rocket development, GPS use for navigation was off the table. Getting carrier phase 1st order products to work became critical for Trimble’s survival. In May of 1986, Trimble shipped an order of seven survey systems to the California Department of Transportation (Caltrans). Earthquake monitoring was a niche market add-on. Another “bet your company” deal was a Japanese order of 25 dual frequency systems.
During this time Trimble started to realize GPS was more than a device — that time-stamping events and geo-tagging things made it a valuable information technology component. The real value was in the information. By 2000, the Hong Kong price of the GPS function in quantities of a million devices a month was $1. GPS became ubiquitous and a fundamental component of a thriving information technology market.
GPS started out as a real-time worldwide system for navigation. It is now an indispensable part of modern life. GPS has truly changed our world.
The Global Positioning System (GPS) project started 50 years ago, in 1973. I was fortunate to be part of incorporating GPS into the National Spatial Reference System (NSRS) when I worked for the National Geodetic Survey (NGS). GPS was not considered operational until 1993, but NGS started performing GPS surveys in 1983. Geodetic control surveys that formerly took six to 12 months to perform using classical methods could be performed with GPS in a few weeks using fewer personnel and resources. It changed the way NGS and others performed their surveying operations.
While one group in NGS was developing programs to evaluate and compute coordinates using GPS, another NGS group was completing the readjustment of the North American Datum of 1983 [NAD83 (1986)]. The analysis of GPS indicated that some of the latitude and longitude values estimated using GPS did not agree with the published NAD83 coordinates. The classical techniques used a triangulateration process (involving angles and distances) that required several triangles to connect two stations that were not intervisible. GPS, on the other hand, could directly measure the distance between the two stations, resulting in more accurate coordinate differences.
To support surveyors, NGS, working with other federal agencies under the auspices of the Federal Geodetic Control Subcommittee (FGCS), developed a GPS test network in the Washington, D.C., area to demonstrate whether a specific manufacturer’s GPS receiver and associated geodetic post-processing software was an accurate relative positioning satellite survey system. This facilitated the use of GPS for incorporating geodetic control in the NSRS. As mentioned above, GPS surveys exposed many inconsistencies between existing NAD83 (1986) control. Organizations such as NGS and state transportation departments that performed control surveys used GPS as soon as equipment met the federal testing requirements because it was more efficient and cost-effective than classical techniques. This led individual states to perform statewide geodetic network projects to upgrade their NAD 83 (1986) coordinates. These surveys were ultimately designated as High Accuracy Reference Networks (HARN).
In the beginning, the attitude of the individual surveyor accepting GPS was one of “trust after verifying.” Many surveyors considered it to be a “black box” that could not be trusted. Surveyors were accustomed to having angles and distances they could write down and check the results. Also, there were some key challenges and limitations of using GPS for surveying in the early days. This included the cost and size of the equipment, the peripheral devices required, the power requirements (including 12v car batteries and generators), “black box” computer processing software, obstructions near monuments, and limited visibility of GPS satellites.
Prior to GPS becoming fully operational, some surveys had to be performed in the middle of the night to have four or more satellites visible during the observing session. This required a significant amount of technical planning, which sometimes required complicated logistics for coordinating observing sessions. Also, at that time, most private surveyors did not perform control projects, so even though GPS may be more accurate, it was not more cost-effective than classical techniques for their typical projects.
Over time, after GPS became operational, more surveyors (and other professionals) embraced using GPS after the cost of receivers decreased, user-friendly processing software became available (e.g., NGS OPUS), Continuously Operating Reference Stations were densified (e.g., NOAA CORS), and statewide Real-Time Networks (RTN) were established (e.g., North Carolina RTN). GPS technology now underpins many sciences, large areas of engineering (such as driverless vehicles and UAVs), navigation, and precision agriculture. GPS (today GNSS) and its applications have changed the way surveyors and geospatial users perform their work, and the world has seen the development of applications that were not ever imagined 50 years ago.
The Air Force was initially opposed to GPS. How did that change?
Between 1978 and at least the mid-1980s, maybe even the late 1980s, the Air Force tried several times to cancel the program. At the time, I was a Capitol Hill staffer for the House Intelligence Committee. In one of those efforts to cancel GPS, Tom Cooper, who was a lead staffer for the House Armed Services Committee, came to me and said, “Can you guys give any reason for keeping GPS?” And I said, “Yes, it greatly improves the accuracy of SIGINT [signals intelligence] locations. It makes a very big difference.”
So, Tom used that, along with other arguments, for why we should keep GPS. The Committee and Congress ultimately decided they would, despite the Air Force’s resistance.
The Air Force’s resistance came from the Strategic Air Command, which in the 1980s believed it would never use satellites. They were concerned about the satellites being shot down. I found this amusing because they were flying around in aircraft at a few thousand feet and were concerned about satellites flying at 11,000 miles. But they were, so they were laggards.
Image: USAF/Staff Sgt. Kyle Johnson
Which service adopted GPS first and why?
The service that by far led the way was the Army. It spent $100 million a year absorbing NRO capabilities. They also spent money on GPS, though not as much. By the time we got to the first Gulf War, in 1991, we had a partial GPS constellation — I think of 18 satellites of the 24 required — and that meant that you didn’t have 100% coverage all day long. So, coverage maps of their areas of interest were generated every day to let people in the field know when they would have service. Most of them didn’t have receivers either. Most of the receivers they did have were Precision Lightweight GPS Receivers (PLGR), knows as “pluggers”, which were the first “handheld” receivers, but they were pretty big.
Once the fight got going, many of the troops wrote home and asked their moms and dads to send them civilian receivers.
Yes! Thousands and thousands of them showed up in theater. Some troops taped them to the windscreens of their helicopters or jet aircraft. They were just jury-rigged into everything because, despite their limitations at the time, they were very, very useful, unlike anything else. So, now everybody realized, “Oh my goodness, this is really a big deal. This is a game changer!”
Then we got more modern receivers, integrated receivers, the whole thing. However, at the end of the Gulf War, the Air Force still had no plan to equip any of its aircraft with GPS. As Assistant Secretary of the Air Force, I was called over to the Armed Services Committee and asked, “What is your plan for integrating GPS receivers into your aircraft fleet?” I said, “There is no plan.” and they were incredulous. They looked at me like “Well, you’re an idiot.”
It wasn’t me, however, and the staff knew my story before I gave it. As a result, Congress mandated it. They put it in that year’s National Defense Authorization Act (NDAA). Within less than 10 years you had Joint Direct Attack Munitions (JDAM) and other GPS-guided weapons. So, that got it moving quickly.
By the end of the 1990s, the Air Force was fully on board and were equipping their aircraft with many weapons that depended on GPS. Meanwhile, GPS had moved to a full constellation of 24 satellites. Full operating capability was declared in 1995. The Navy proceeded similarly, but they were somewhat less affected. So, the Army remained a leader in using space.
The Chief of Staff of the Air Force asked me about Air Force use of GPS. I said, “Chief, the Air Force builds a lot of space stuff, but it doesn’t use it.” Of course, a short time later it was using it extensively. So, this ramp-up was very rapid — just a few years from “I don’t give a darn about these things” to “I can’t live without them.”
Brad Parkinson and his successors as JPO directors designed and built the system but had no role in its adoption, right?
No. They were going turn it over to the production house, if you will, and they did. Once the Air Force got on board with GPS guided weapons, adoption proceeded rapidly.
What about the Navy?
I don’t recall the Navy particularly. I do not at all accuse them of being laggards. I think they did what they needed, whatever that was.
Did later NDAAs expand that mandate to the other services?
I don’t know. I was out of the government by that time, so I lost track. I don’t think it was necessary. What people didn’t understand immediately was that you could do anything with this system. At the end of the day, it is a super accurate timing signal. There are many things you could do with that and people have done them. It quickly became evident that it was so pervasively useful, that anything you could think of involves GPS, from the era of the first Gulf War onward. By 10 years later, many weapons systems in all the services were GPS-guided. I later served on the board of ATK and we were building GPS-guided artillery rounds. I am pretty sure that the ATACMS [Army Tactical Missile System] you hear about today is GPS guided.
So, in a couple of years, all the services wanted to integrate GPS in all their platforms and weapons.
Well, except that the amazing thing was, despite all the things that people had done with GPS in the Gulf War — starting with those helicopters that went in the first night and took out the command and control system, which were guided by Army-provided pluggers taped onto the windscreens by their pilots, and downed pilots using GPS to give their coordinates to the rescue teams — at the end of the war the Air Force still didn’t have a plan to put them on its aircraft! That’s when Congress mandated it. It was amazing.
Despite that, once they got going, particularly once they got going with GPS-guided weapons, everything changed. I don’t know whether the Air Force became leaders, but they were certainly aggressive integrators of the program into the service. There was no more, “We won’t use satellites” and all that.
That was after my time. I left government in early 1993. There were other big fish to fry at the same time. As important as I realized it was, I still didn’t realize how important it was, and I was way ahead of most everybody else, in the Air Force anyway.
The Federal Aviation Administration’s (FAA’s) chief scientist at the time said, “The great thing about GPS is that it is a tool around which you can build myriad capabilities.” He outlined a few for the FAA, many of which they have since done. The same thing began to happen in the services, particularly in the Air Force, in which GPS-guided weapons were pervasive within 10 years.
Part of Brad’s motto for JPO was “The mission of this program office is, number one, to drop five bombs in the same hole.”
Yeah. By the way, one mistake that people make a lot is they think there were GPS-guided weapons during the first Gulf War. That was not the case. There were none by then. There were precision guided munitions that were guided by maps and lasers and a variety of means. But, despite the belief of many authors, there were no GPS-guided weapons at that time.
So, which was the first conflict in which GPS was used?
It was the Iraq War, in 2003. It was a major user of GPS-guided weapons.
Any other thoughts on the 50th anniversary from the military side of things?
It is impossible to overemphasize the importance to military operations and, frankly, to civilian life as well, of being able to easily and accurately navigate or have highly accurate time.
You can do it with a $100 receiver, whereas it used to require a $10,000 receiver and you had to have it re-initialized from a standard. So that’s what everybody does. Now, this has created probably more dependency than is healthy and many nations have backup that we don’t have.
Such as Loran-C. That’s a big subject of debate these days, as you know.
Well, it’s been a subject of debate for 20 years. Everybody agrees, but nobody moves.
The Department of Transportation recently released an action plan on the adoption of complementary PNT systems. So, there’s some movement.
As a one-time government bureaucrat, what you do when people are on your back is launch a study and say, “Well, it will be done in a year or two.” They have done this time, after time, after time.
“I know where we are. I do not need a satellite system to tell me!” In the 1970s and 1980s, this was the number one military and civilian response to what GPS does. The existing military hardware included navigation systems and the defense industry had a vested interest in keeping its business. Civilian interest in GPS was low because of the program’s uncertain funding. The armed services saw no reason to add a new program to their budgets and were opposed to GPS.
The military program approval process was also inconsistent with the rapid changes in digital technology. The first GPS satellite was launched in February 1978, the first PC was released in August 1981, and the first Mac in January 1984. GPS went through a development process to build user equipment, test it to make sure it met military requirements and then build the limited-rate production equipment with a design about six years old.
Early GPS Manipack worn by JPO Army deputy Lt. Col. Paul Weber. This photo graced the cover of the first ever GPS brochure. (Image: GPS World archives)
My favorite joint service story is that our low cost, 19-lb, $55,000, hand-carry man pack flunked its first testing sequence. The Army placed it into an alkaline bath in September 1985, that ate the o-ring and caused it to fail the bio/chem decontamination requirement. The o-ring was an Air Force requirement because at 60,000 ft without venting the device would become a potential bomb. Yet, pressure relief failed to meet the Navy Seals’ requirement for underwater operation. The fixed man pack was now our limited rate production set. Developments in digital technology during the process made it overweight, over cost and unsuitable. To get hand-carry receivers, it became necessary to purchase modern civilian sets at the unexpected outbreak of the First Gulf War in 1990.
JPO ran a competition for 200 civilian receivers that had no military requirements to send them to the operational forces for training. Trimble won the competition and when the war came the following year with only 12 GPS satellites operational, JPO asked Trimble to deliver as many sets as it could produce at the price bid for the competition to augment the deliveries of the limited rate production military set. Talk about an operational education! The Army tank drivers who did not want GPS because “The war comes to us, so we do not need GPS” instantly demanded GPS receivers when they began to get lost by more than 10 miles on the featureless desert. The deployed troops began asking their parents for GPS receivers for personal use. The war integrated GPS into all military operations.
Realizing the value of GPS inter-service integration of forces, the military believed the civilian signal should only have degraded accuracy. But in May 2000, President Clinton decided the civilians also should have good accuracy and ordered that the degradation of the civilian signal (called Selective Availability) should cease. Today everybody is aware of what GPS provides. You never hear anyone say, “I know where I am, I do not need satellites to tell me.”
VectorNav Technologies has released two products, the VN-210-S and VN-310-S, which expand its tactical series of GNSS-aided inertial navigation systems (INS).
The VN-210-S GNSS/INS combines a tactical-grade inertial measurement unit (IMU) comprised of a 3-axis gyroscope, accelerometer, and magnetometer with a triple-frequency GNSS receiver. The integrated 448-channel GNSS receiver from Septentrio adds several capabilities, including L5 frequencies, moving baseline real-time kinematic with centimeter-level accuracy, support for Galileo OSNMA and robust interference mitigation.
These capabilities and high-quality hardware offer improved positioning performance in radio frequency-congested and GNSS-denied environments.
Image: VectorNav
The VN-310-S dual GNSS/INS leverages VectorNav’s tactical-grade IMU and integrates two 448-channel GNSS receivers to enable GNSS-compassing for accurate heading estimations in stationary and low-dynamic operations. The VN-310-S also gains support for OSNMA and robust interference mitigation, offering reliable position data across a variety of applications and environments.
The VN-210-S and VN-310-S are packaged in a precision milled, anodized aluminum enclosure designed to MIL standards and are IP68-rated. For ultra-low SWaP applications, VectorNav has introduced L5 capabilities to the VN-210E (embedded) when using an externally integrated L5-band GNSS receiver.
The European Union is in the final stages of completing a deal with SpaceX to launch four Galileo navigation satellites in 2024, reported SpaceNews.
In press briefings during the European Space Summit in Seville, Spain, Thierry Breton, the European Commission’s commissioner for the internal market, said that he was “finalizing the discussions” for a pair of Falcon 9 launches, each carrying two Galileo satellites, tentatively scheduled for April and July of 2024.
Brenton also said that the final obstacle to completing the launch contract was negotiating a security agreement to protect sensitive technologies on the Galileo satellites, which previously had been launched from the European spaceport in French Guiana, when those satellites are being prepared for launch from the United States.
The launch contract itself was completed in July, Breton noted, and that the European Commission had approved a European Space Agency proposal to use the Falcon 9 for launching those satellites. He said the European Commission would spend $192 million on the Falcon 9 launches.
During a recent meeting of the European Space Agency (ESA) Council, ESA Director General Josef Aschbacher said that the final decision for using SpaceX to launch the Galileo satellites was in the hands of the Commission.
“We have prepared on the ESA side the contractual arrangements with an external launch company, but whether or not the launch will be decided to take place with SpaceX is not in our hands,” he said. “the European Commission will decide.”
There had been discussions for more than a year about using a non-European rocket, such as the Falcon 9, for launching those satellites because of delays in the Ariane 6, the retirement of the Ariane 5 and the withdrawal of the Soyuz after Russia’s invasion of Ukraine. Those satellites would augment the existing operational Galileo constellation and serve as on-orbit replacements if other satellites fail.
ESA had already contracted with SpaceX for three Falcon 9 launches. The ESA said it chose the Falcon 9 after the loss of the Soyuz, delays in the Ariane 6 and concerns about the Vega C, which remains out of service since a launch failure in December 2022.
I/NAV improvements for all Galileo Open Service users is a part of the new Galileo services portfolio. (Image: EUSPA)
In 2023, Galileo continues to provide the world’s most precise satellite navigation information, to more than four billion users worldwide. Galileo services have expanded with many new capabilities that are unique with respect to other GNSS.
EUSPA and ESA continue to enjoy an effective collaboration on the many development, deployment and evolution activities of the Galileo Program, each according to its responsibilities for service provision and system development with the European Commission acting as the program manager.
Stable service performance
The service delivery operations, and the maintenance of the operational systems, are managed by EUSPA, who supervises several contracts that carry-out the day-to-day activities from dedicated control and monitoring centers throughout Europe. The Galileo timing, navigation and SAR/Galileo services provided in 2023 have been delivered with excellent performances that continue to exceed the formal declarations for minimum performance levels (MPL), both in terms of absolute accuracy and overall service availability.
Expansion of service portfolio
Galileo FOC batch three satellites in storage at OHB Systems. (Image: ESA)
The service provision teams have been able to focus on improvements to, and expansion of, the Galileo service portfolio.
OS and I/NAV improvement
Galileo Open Service (OS) users can already benefit from an improved navigation message, being broadcast by the Galileo constellation since mid-2023, which considerably boosts their performance in terms of robustness and time to first fix.
An update of the Galileo OS service definition document (SDD) is planned for the end of this year. This fourth issue of the OS SDD will bring to the users new MPLs (e.g., ranging rate accuracy and ranging accuracy at high percentiles) and improvements of existing MPLs, such as the timeliness of certain notice advisories to Galileo users. This updated OS SDD will also introduce the OS extended operation mode, which is characterized by a gradually degrading ranging accuracy with respect to the nominal operational mode, including outages of the Galileo ground segment, thus increasing the robustness of the OS.
High Accuracy Service
As of the HAS initial service declaration on January 24, Galileo became the first GNSS constellation ever to enable a decimetre-level accuracy, free of charge on a 24/7 basis over most parts of the globe in nominal conditions. The HAS corrections are transmitted directly via the Galileo signal in space (E6-B) and through the internet with the corresponding performance levels systematically met since the declaration. All documentation available here.
OS-NMA
The OS Navigation Message Authentication (OSNMA) will be a free and open access service allowing the users to confirm that received Galileo navigation data has not been modified and originates from the Galileo system, thus increasing the likelihood of detecting spoofing attacks at the data level and significantly contributing to the security of the solution. The OSNMA public observation phase is currently ongoing (gsc-europa.eu/support-to-developers/osnma-public-observation-test-phase). As part of that, the final OSNMA signal in space (SiS) interface control document (ICD) was published in December 2022, while the broadcast of a compliant SiS together with test certificates for the public key infrastructure started in August, marking the start of the OSNMA initial operational capability. The OSNMA initial service declaration will be achieved after the completion of the service validation activities and is targeted for early 2024.
Safety of life
The Galileo contribution to safety of life services (GoSoL) will cover the provision of Galileo signals and of service guarantees to enable the implementation of horizontal ARAIM service supporting aviation users. The service roadmap is currently under definition with a stepwise approach that will include the broadcast of a test ISM before the operational service is provided.
SAR
SAR/Galileo provides accurate, timely, and reliable distress alert data to help rescue authorities assist in distress situations (forward link service). It also acknowledges the receipt of the distress forward link alert to the beacon in distress via the Galileo navigation SiS (return link service). SAR/Galileo is a geographically distributed system, which was extended with a fourth European MEOLUT installed in La Reunion, in operation since November 2022.
The combination of SAR/Galileo space and ground assets provides excellent performance levels with a mean location accuracy of less than 800 m and a return link delivery latency of less than 1 min, which assisted in the rescue of approximately 1,400 people within EU territories in 2022.
Utilizing the return link service capabilities brings new innovations that further contribute to the global emergency space operations as Galileo moves forward to the implementation phase of the emergency warning satellite service (EWSS). The EWSS will provide national civil protection authorities with a satellite broadcasting capability to broadcast on-demand authenticated alerts to a precise target area and its population directly to any device capable of processing Galileo signals.
Reference documents for each of the above services can be found at the EUSPA European GNSS Service Center website, including technical notes, interface control documents and service declaration documents.
Image: European Space Agency (ESA)
Full operational capability infrastructure development toward completion
Space segment
The production of the third batch of Galileo FOC satellites, by the satellite manufacturer OHB Systems, has been completed for an overall amount of 12 satellites. The acceptance review for the last couple of spacecraft took place in June.
This amounts to an overall production by OHB Systems of 34 Galileo FOC Satellites (14 satellites in batch one, eight satellites in batch two and 12 satellites in batch three) of which 24 are in orbit. The remaining 10 satellites are in storage waiting for the next launch opportunity in 2024.
Ground segment
G2SB1 engineering model payload testing at ESA ESTEC. (Image: ESA)
The ground segment is going through a major upgrade with the roll-out of the new System Build 2.0 infrastructure in support of public regulated service IOC and open service FOC.
The new version of the ground mission segment developed by Thales Alenia Space France will be oriented to increase service robustness and resilience, besides high performance. It will provide virtualized hardware and software infrastructure at the Galileo Control Centers, triple receiver chain redundancy in the sensor stations’ remote sites and two additional sites located in Wallis (Pacific Ocean) and Bonaire (Caribbean Sea) to increase global coverage with 15 sites overall. A new mission monitoring capability has been implemented for the operators using the SAFE/Agile methodology. Furthermore, a system extended contingency mode will be implemented to cope with outages lasting up to seven days with smooth navigation performance degradation.
A new version of the Galileo Security Facility will be deployed at the Galileo Security Monitoring Centers offering an evolution of the public regulated service (PRS) capabilities through new enhanced SiS access control. Furthermore, a new state of the art cyber security monitoring system will be implemented.
The System Build 2.0 infrastructure qualification was completed by ESA in July. Migration in operation is based on an innovative concept consisting of a replica of the operational chains to ensure seamless transition from the current system in operation to the newly deployed one. The completion of the migration into operations is planned for the beginning of 2024, with the schedule being continuously monitored at the program level.
Galileo Second Generation: a constellation of state-of-the-art procurements. (Image: ESA)
An upgrade of the ground control segment in charge of command and control of the constellation is under qualification by the industrial consortium led by GMV. It will provide additional flexibility to allow for deployment in between launches and to address resolution of hardware and software obsolescence, including cyber security, operability improvements and a security monitoring overlay. Furthermore, it will upgrade the Telemetry Tracking and Control (TTC) station in Redu, Belgium, and deploy an additional station in Fucino, Italy, co-located with the Galileo Control Center, bringing to nine the overall number of TTC stations.
Second generation fast forward
Galileo’s second generation (G2G) will introduce many innovative technologies to offer unprecedented precision, robustness, and flexibility.
For the development of G2G activities 2023 was a key year, with the development of the first batch of G2 satellites, the start of all contracts for in-orbit validation of the ground segment and system test beds and the preparation of the initial operational capability (IOC) design, through the consolidation of the mission/service roadmaps with the EC, EUSPA, and the delegates from EU member states.
This year, Europe has taken the necessary steps to unchain the development of key GNSS features, which will exponentially enhance GNSS accuracy for the worldwide communities in the future:
New and improved services.
Unique flexibility of ground and space systems to enable 12-18 months service time to market, without the need for constellation replenishment.
Upgraded robustness of key infrastructure items.
State of the art GNSS technology leading to centimeter-level precision.
New GNSS signals, including extended data capacity for added value services.
And of course, as a key factor, a full backward compatibility with Galileo First Generation and other GNSS systems.
G2G: Incremental steps for enhanced capabilities over the next decade
The ESA completed the G2G system preliminary design review in July, focused on three key incremental phases of the G2G:
G2G In-Orbit Validation (G2GIOV): specification, design and validation activities for the sake of ensuring the full development of the first batch of G2G satellites and all the associated infrastructure for launch and early orbit phase, in-orbit testing, in-orbit validation, initial enhancement of Galileo services and addition of new Galileo service components.
G2G Initial Operational Capability (G2GIOC): design and specifications required for the complementary procurements that will ensure new Galileo services, as enabled by G2G infrastructure, including both the second batch of G2G satellites and the G2G ground segment.
G2G Full Operational Capability (G2GFOC): Identification of key technological enablers and additional capabilities required for final G2G implementation, including the bridge to future synergies with other EU and ESA programs.
G2G in-orbit validation infrastructure – satellite hardware under validation
G2SB1 acoustic testing in Rome and structural model arrival at ESA ESTEC. (Image: ESA)
The two parallel contracts with Thales Alenia Space and Airbus to develop and manufacture each of six G2G batch one satellites (G2SB1A and B) achieved key milestones this year.
On the G2SB1 satellite A side, the prime contractor tested engineering model payloads and structural models at its premises and delivered them to ESA’s Technology Center (ESTEC). The validation of the new G2G payload capabilities and the key mechanical, vibration and acoustical testing milestones have been achieved.
These satellites will provide the following key innovations: reconfigurable fully digital navigation payload; point-to-point connection between satellites by inter-satellite-link for command and control, and ranging functionalities; electric propulsion for orbit-raising capabilities; advanced jamming and spoofing protection mechanisms; on-board authentication capabilities; increased ground-to-space data rate; and improved time reference (number of clocks and advanced clock monitoring functions).
Key mechanical and launch-related tests on the structural models stacked configurations were performed in the last quarter of this year, in order to simulate the launcher environment and satellite separation dynamics.
On the G2SB1 satellite B and the PHM and RAFS clock manufacturing sides, activities are ongoing as planned, with key HW infrastructure developed and tested in the respective Industrial Primes premises.
This included as key events in 2023 the full testing of the satellite advanced engineering model antenna and the creation of a satellite atomic clock farm in industry premises to produce the more than 70 atomic clocks required for the 12 G2 batch one satellites.
The next steps for these contracts are the completion of the equipment and satellite CDRs, expected in the coming months, in order to engage (starting at the end of 2024) with the critical system compatibility test campaigns of the G2G IOV ground segment infrastructure and system engineering test beds under development.
Galileo Second Generation batch one satellites. (Image: ESA)
G2G in-orbit validation infrastructure – ground segment and test beds in full development
The key system engineering, ground segment and test beds infrastructure procurements were all awarded during the first semester of 2023, giving EC/EUSPA/ESA and the industrial teams a brief moment of respite and celebration.
Following a competition process that encompassed about 12 months of detailed technical, management and legal interactions, 11 industrial prime contractors were selected for a set of contracts engaging about $1 billion euros of public sector investment:
Four contracts for system engineering, signal and performance, system validation and security and PRS activities.
Four contracts for ground segment in-orbit validation infrastructure.
Three contracts for system test bed activities plus a series of technological developments in the receivers and constellation simulation side.
Once completed in the years to come, these infrastructure developments will ensure not only the launch and early orbit phasing and in-orbit validation of the novel G2G satellite’s capabilities, but also enable the provision to all world users of enhanced Galileo services.
G2G satellites stacked configuration for launcher simulated test at ESA ESTEC. (Image: ESA)
G2G initial and final operational capability moving ahead
In line with the outcomes of the system preliminary design review, two new lines of GNSS improvements are well underway at program level.
In the area of G2G initial operational capability (IOC), which will provide new G2G initial services, an extensive preparatory work has been performed by EUSPA in order to derive the mission needs (as defined by the EC and its Member States), into a set of service evolution roadmaps for the more than one dozen Galileo services.
This work has been supported by ESA dossiers providing incremental implementation of these services, in a continuous improvement ramp-up process, which guarantees backward compatibility and seamless enhancement.
The relevant procurements that will enable, in combination with the in-orbit validation infrastructure, the provision of these services are currently under consolidation:
G2G IOC ground segment, with an initial version to be procured in 2024.
G2G satellites batch two, which is expected to start its competitive procurement procedure in the second part of the EU’s 2021-2028 multi-financial framework.
In addition, work is well advanced in the definition of the key technological developments and system trade-offs that will be analyzed for inclusion in the G2G final operational capability (FOC), expected early in the 2030s.
Critical technologies being analyzed include optical inter-satellite links, advanced governmental payloads, new ground segment and signal technologies and in-space constellation monitoring, among others. ESA expects to complete the preparation of the system-critical design review by the end of 2024 or early 2025 and to submit it for in-depth review by the EC, EUSPA and European member states stakeholders.
Conclusions
Galileo keeps providing continuous and stable services to users with new enhanced capabilities offering high accuracy, authentication and faster time to first fix. The space and ground infrastructure development for the first generation is progressing toward public regulated service IOC and open service FOC.
In parallel, for G2G, hardware production of the new satellites is well under way and the ground segment development has started to maintain Galileo competitive with the other GNSS.
We continue to strive toward achieving the vision defined at the end of the previous decade: “If you can imagine a novel satellite navigation service, we will implement it in 12-18 months.”
Warning sirens about the vulnerabilities of GPS to jamming, spoofing, solar activity and other disruptions have been blaring for many years. Now the U.S. Department of Transportation (DOT), which represents other federal civil departments and agencies on all GPS-related matters within the federal government, might finally be moving from study to action. On September 12, at the annual meeting of the Civil GPS Service Interface Committee held in conjunction with ION GNSS+ in Denver, Robert Hampshire, DOT’s Deputy Assistant Secretary for Research and Technology and Chief Science Officer, announced the release of DOT’s Complementary Positioning Navigation and Timing Action Plan. It aims to drive CPNT adoption across the United States transportation system and within other critical infrastructure areas. You can read more here and download the planhere.
Which GPS vulnerabilities does DOT aim to address and how quickly can it “drive adoption” of CPNT? Attempting to answer these questions requires pushing through a dense thicket of bureaucratic jargon. I asked Karen Van Dyke, Director for Positioning, Navigation, and Timing (PNT) and Spectrum Management in Hampshire’s office four questions. What follows are excerpts from her answers. You can read her full response here.
What is your office’s charter within the federal government to advance the development and deployment of complementary PNT?
Her office’s efforts, Van Dyke told me, “support federal policy governing PNT programs and activities for national and homeland security, civil, commercial, and scientific purposes. These include Executive Order 13905, Strengthening National Resilience Through Responsible Use of Positioning, Navigation, and Timing Services (EO 13905) and Space Policy Directive 7, The United States Space-Based Positioning, Navigation, and Timing Policy (SPD-7).”
Which GPS vulnerabilities and at what scale is this plan addressing?
The action plan, Van Dyke told me, “addresses disruption, denial, and manipulation of GPS for critical infrastructure sectors” on “both a widespread and local scale.”
How and when will this action plan move the federal government’s posture on CPNT from study to action?
Van Dyke cited field demonstrations conducted in 2020 by the Volpe Center of candidate PNT technologies that could offer complementary service in the event of GPS disruptions and a 2021 report to Congress that distilled the PNT resiliency recommendations. DOT, she said, should develop “system requirements for PNT functions that support safety-critical services” and “standards, test procedures, and monitoring capabilities to ensure that PNT services, and the equipage that utilize them, meet the necessary levels of safety and resilience”.
How does DOT intend to engage PNT stakeholders?
Van Dyke pointed to a PNT Industry roundtable that DOT held in August 2022 that included representatives from CPNT technology vendors and critical infrastructure sectors and “informed the development” of the action plan. She also pointed out that on September 11, DOT issued a request for information “as one of the steps to drive adoption” of CPNT services “to augment GPS for the nation’s transportation system, and through the executive branch interagency process, for other critical infrastructure sectors.”
The ULA Vulcan Centaur launch vehicle. (Image: ULA)
The United States Space Force’s Space Systems Command (SSC) has assigned 21 launch service mission assignments for the National Security Space Launch (NSSL) Phase 2 Launch Service Procurement contract. This is the fifth and final order year in the Phase 2 contract.
United Launch Alliance (ULA) received 11 mission assignments and SpaceX received 10. These missions are scheduled to launch over the next two to three years and focus on a variety of mission areas.
The 11 missions assigned to ULA are: GPS III-9, NROL-73, NROL-56, STP-5, SILENTBARKER 2/NROL-118, GPS IIIF-1, NROL-100, USSF-95, NROL-109, SDA T2TL-B and USSF-25.
The 10 missions assigned to SpaceX are: SDA T1TL-F, SDA T1TR-A, USSF-57, NROL-77, SDA T1TR-E, GPS III-10, USSF-75, SDA T2TL-A, SDA T2TL-C and USSF-70.
NROL-77, NROL-73, NROL-56, NROL-109, and NROL-100 are missions being conducted in partnership with the National Reconnaissance Office (NRO).
T1TL-F is the last mission of six Space Development Agency (SDA) Tranche 1 Transport Layer launches. T2TL-A, T2TL-B and T2TL-C are the first three Tranche 2 Transport Layer launches. SDA’s Transport Layer aims to provide assured, resilient, low-latency military data and connectivity worldwide to the full range of warfighter platforms.
T1TR-A and T1TR-E are the last two SDA Tranche 1 Tracking Layer launches. The Tracking Layer aims to provide global indications, warning, tracking and targeting of advanced missile threats, including hypersonic missile systems.
The GPS III-9 and GPS III-10 missions are the final projected GPS III missions. The GPS IIIF-1 is the first launch of the follow-on GPS III satellites. GPS Block IIIF introduces several improvements and novel capabilities compared to previous GPS satellite blocks.
SpaceX’s Falcon Heavy launch vehicle. (Image: SpaceX)
USSF-57 will launch the first of three next generation overhead persistent infrared GEO satellites. These satellites will deliver survivable, resilient missile warning, tracking, and defense in a highly contested and congested space domain.
SILENTBARKER 2/NROL-118 is a joint NRO and SSC Space Domain Awareness mission to meet U.S. Department of Defense (DOD) and intelligence community space protection needs.
USSF-25 will launch the Defense Advanced Research Projects Agency’s Demonstration Rocket for Agile Cislunar Operations (DRACO). The goal of the DRACO program is to demonstrate nuclear thermal rocket in orbit.
USSF-95 will be the first launch of a missile track custody (MTC) prototype satellite. The MTC prototype effort will evaluate the ability of various next generation overhead persistent infrared sensor designs to meet missile tracking requirements.
STP-5 is the latest mission in support of SSC’s Space Test Program (STP). The STP performs mission design, payload-to-bus integration, space vehicle-to-launch vehicle integration, and on-orbit operations for science and technology payloads that exhibit potential military utility. STP-5 will launch two satellites in support of the DOD’s Strategic Capabilities Office.
Fifty years since it was designed and approved by the U.S. Department of Defense (DOD), the GPS is at risk of losing its status as the world’s gold-standard location service, reported The Wall Street Journal.
In a recent paper published by Harvard’s Belfer Center for Science and International Affairs, “China’s BeiDou: New Dimensions of Great Power Competition,” Sarah Sewall, executive vice president for strategic issues at IQT and co-authors Tyler Vandenburg and Kaj Malden outline their finding that China’s version of GPS is part of the country’s longstanding effort to join the technological ranks of leading nations and use its capabilities to achieve geopolitical advantage across the globe.
Sewall’s assessment of BeiDou’s technical superiority received some unexpected support from a government advisory board on GPS, which stated that “GPS’s capabilities are now substantially inferior to those of China’s BeiDou,” and urged the administration to regain U.S. leadership in the field.
The BeiDou constellation is newer and has more satellites than any other system and has more than ten times as many monitoring stations around the world than GPS does. As a result, BeiDou’s accuracy is much better in many places, including the developing world.
Sewall points out that in cases where BeiDou provides the most accurate positioning, navigation, and timing (PNT) data, particularly in the global south, China may be able to influence other nations’ economies, stating that it is one example of “a new form of great power competition that most in the U.S. government don’t recognize.” China is providing superior PNT information to enhance its diplomatic, economic and military power and the United States cannot afford to cede this area of longstanding advantage.
BeiDou being newer and more advanced than other GNSS, makes it easier for China to encourage other nations to use its signals and purchase specialized equipment, especially when equipment purchases are heavily subsidized by the Chinese government, harming the U.S. economy and its status as the leader of GNSS technology.
Recent launch and surveillance fears
On May 16, 2023, China launched its most recent BeiDou satellite to replenish the constellation, bringing its total to 56 satellites, nearly twice as many as the 31 GPS satellites.
The latest BeiDou satellites also feature two-way messaging, a feature that GPS does not have. It is mainly available in China and requires special chips that are not widely available in the consumer market. It enables users to send short messages in areas without ground network cell coverage and can be used for search and rescue operations.
The CNBC report noted the fear that, with its most recent enhancements, the BeiDou system could be used as a surveillance device — as the two-way messaging feature reveals a user’s locations as well as other types of data.
Additionally, with the growing number of applications for cellphones and an increase in autonomous vehicles that use the BeiDou system, more and more user data is being transmitted.
The U.S. military is upgrading GPS with more-modern satellites that are designed to give nonmilitary devices more-precise coordinates in more indoor and hard-to-reach spaces. However, the next-generation GPS service for civilians is not expected to be released for several years.
GPS pioneered the PNT industry by offering civilians a new, free-to-use system. While originally developed for DOD, it turned into a critical global infrastructure that underlies a vast swath of the U.S. economy.
Besides GPS and BeiDou, there are two other global navigation satellite systems (GNSS), Russia’s Glonass and the European Union’s Galileo, as well as regional systems from Japan (QZSS) and India (NavIc).
BeiDou, once a small regional network with clunky receivers and few civilian users, has grown significantly since launching its first two satellites in 2000. It now has more than 30 precision-enhancing monitoring stations and claims to pinpoint users’ locations to within several centimeters, along with offering basic two-way communication capabilities.
Both BeiDou and GPS offer a variety of nonmilitary benefits that expand beyond the systems’ original expectations, from Uber drivers who often rely on a smartphones GNSS data to locate customers to farmers who can use GPS-based applications for farm planning, field mapping, solid sampling and more. GPS has been called “the silent utility” because signals are used in almost every technology, said Dana Goward, president of the Resilient Navigation and Timing Foundation.
Looking forward
GPS guides U.S. missiles, ships and troops through more-secure military frequencies kept separate from its civilian signals. Its past dominance even made rival militaries reliant on the Pentagon-controlled system.
The U.S. military has long planned to upgrade GPS with a fleet of modernized and upgradable satellites that provide more-precise coordinates subject to less interference. The newer satellites broadcast data to civilian users over a new frequency called L5.
The Space Force has 17 L5-equipped satellites in orbit after a series of delays but has yet to reach the 24 live satellites needed to run a reliable system. Some already-built satellites sit in a Colorado warehouse awaiting their turn for a funded launch.
The Space Force said in a statement that GPS continues to set the gold standard in its field.
“While other nations may report improvements in accuracy and equivalent performance in availability, GPS is still the clear leader in integrity and is the only system accepted for international flight use,” a spokeswoman for the branch’s Space Systems Command told The Wall Street Journal.
GNSS is like opium. Highly addictive, pleasing to the user, but laced with peril when you’re hooked. GPS World readers are well aware of the vulnerabilities, and probably aware of the serious concerns governmental bodies have about our reliance upon it. Here, we consider not so much how it can fail as what the impact of failure is on society, and what mitigations exist to minimize those impacts.
Impact on society
The most commonly cited causes of GNSS failure are jamming (unintentional and intentional) and spoofing. Less well appreciated are solar weather, satellite system errors, receiver system errors and, most importantly, cybersecurity-related errors. Any of these can cause a significant disruption to how society functions today.
The U.S. Department of Homeland Security identified that 15 out of the 18 Critical National Infrastructure sectors were vulnerable to GNSS failure: communications, emergency services, information technology, banking and finance, healthcare and public health, energy (electric, oil and gas), nuclear, dams, chemical, critical manufacturing, defense industrial base, postal and shipping, transportation, government facilities, and commercial facilities.
The threat is real and present. Conflicted areas are routinely jammed and spoofed. Even in peace, GNSS is fragile. In the past year, GNSS interference led to a runway at DFW airport being closed, a 33-hour GNSS outage in the Denver metro area, and even a recent Melbourne Formula One race had to be stopped for 40 minutes due to GNSS data problems.
Mitigations
In most cases, no alternate references are in place, and without them, it is difficult to know that the GNSS data being received is wrong. The ship Stena Impero, for example, was seized by Iran for being in its territorial waters. It is thought to have been victim to spoofing that led it there, but proving it is difficult.
Alternate references exist at low cost, but they generally divide “PNT” into “PN” and “T”, and whether on land, at sea or in the air. On land, most requirements are related to “T” because most applications, such as broadcast facilities and data centers, don’t move, and even when they do, there are enough landmarks available to at least make a sanity check. At sea and in the air, by contrast, motion is the reason we are there, there are few landmarks to confirm location, hence “PN” dominates.
For “T”, armageddon clocks can provide holdover for brief interruptions. However, they must be sufficiently tested to ensure that they succeed. In the Denver incident, radio systems had rubidium clocks for backup, but they drifted too far during the outage to be useable, whereas cellular networks, with alternate terrestrial timing sources, continued to work. Terrestrial time distribution systems over existing IP infrastructure, which Hoptroff supplies, work well globally, but are restricted to land-based time synchronization applications.
For “PN” and “T”, in air, sea and land, low-Earth orbit satellite services such as Satelles, Starlink and OneWeb provide global solutions. Their signals are much stronger than GNSS and therefore are much harder to jam or spoof, but they remain susceptible to interferences such as space weather, which destroyed 40 Starlink satellites on launch last year. However, as the Denver incident shows, until you test the solution, you never really know what might go wrong. eLoran terrestrial wireless solutions are very effective but limited in reach to within a few thousand miles of terrestrial transmitters. Such systems are being installed in South Korea and Saudi Arabia due to their proximity to hostile neighbors. They are likely to be installed in North America and Europe within the next decade.
What all these solutions have in common is that, while they are not expensive, they are not free, and are only available under license. Sovereign GNSS providers have, to date, provided PNT signals at no cost to the consumer. It must be accepted in the new landscape, not just that PNT is no longer free, but also that the supplier can choose its customers. Sovereign GNSS access could be restricted at the whim of a president. Private services are already selective — Starlink chose to provide the Ukraine with service during the current conflict, but it has no obligation to continue to do so.
Get on with the risk register
One of the biggest problems with preparing alternatives to GNSS is that the risk is ignored until it has started to have an impact on business and society. This can be addressed by ensuring that resilient PNT is on corporate and institutional risk registers. It is starting to happen now that governments have started to raise concerns. However, we have a way to go before inclusion on risk registers is a foregone conclusion.
Ligado Networks has sued the U.S. federal government for $39 billion, alleging officials at the U.S. Department of Defense (DoD) misappropriated Ligado’s exclusively licensed L-band spectrum to support secret DoD systems without permission or compensation.
“The lawsuit, filed in the U.S. Court of Federal Claims against the United States, the Defense Department, the Commerce Department and NTIA, seeks just compensation for the government’s physical, categorical, regulatory and legislative takings of Ligado’s property,” the company said in a press release.
According to the company’s lawsuit, the DoD embarked on a “misinformation and disparagement campaign” against Ligado starting shortly after the company received its FCC approvals in 2020. That campaign, according to the lawsuit, sought to revive concerns that Ligado’s 5G plans would interfere with GPS services.
Ligado alleges the DoD’s claims about spectrum interference “are a pretext” to conceal secret Pentagon systems that depend on Ligado’s spectrum.
The company claims multiple former and current senior government officials have acknowledged the DoD wants Ligado’s spectrum for its own, undisclosed purposes, and that the DoD’s activities cannot co-exist with Ligado’s authorized use of its spectrum.
“High ranking U.S. government officials have acted deliberately to deprive an American company of its rightfully licensed property,” said Ivan Seidenberg, chairman of Ligado’s board of managers.
Its complaint states the DoD, U.S. Department of Commerce (DoC) and the National Telecommunications and Information Administration (NTIA) have deprived Ligado of all the economic benefits it could have expected from using and developing its exclusively allocated and licensed spectrum for terrestrial services.
Ligado is asking the court for “just compensation in an amount to be determined at trial for its past, present, and future taking of Ligado’s rights.”
