“NAVGUARD is a compliment to GEODE,” said Frank Wilms, Principal at FDC and project coordinator for both the GEODE and NAVGUARD projects. “Where GEODE is developing mostly receivers for mobile platforms, the objective of NAVGUARD is to monitor threats to PRS signal integrity, to provide technologies to detect illegitimate activities in GNSS frequency bands and geolocate the sources of malicious activities. This will employ a range of system elements, which will ultimately provide a robust and trustable PRS-based PNT capability for our end user equipment.”

Full R&D program

Among the core elements being developed under NAVGUARD is a complete surveillance system, consisting of ground-based sensors and a space-based surveillance subsystem. “We will be prototyping a range of space payloads, one of which will be launched in the frame of the next four years,” Wilms said, “and there will be an information management subsystem which is at the center of the information platform. This will gather data on threats to PRS signal integrity and redistribute it to the users.”

User equipment, including new PRS mobile receivers, also to be prototyped under the NAVGUARD project, will form elements contributing to the collection of threat identification data. “The NAVGUARD endeavor will also deliver a number of other innovative technology elements whose purpose will be to increase PRS PNT robustness,” Wilms said.

NAVGUARD, just launched in February 2023, brings together 31 companies from 11 countries and will run for four years. Like GEODE, it encompasses operational system demonstrations, including the above-mentioned space payload in orbit. It is co-funded under the European Defence Fund (EDF) 2021 framework, comprising an industrial consortium that includes coordinator FDC, Thales, Leonardo, OHB, GMV, Aerospacelab and many others.

Speaking at the recent Munich Satellite Summit, Wilms said, “This is the first time the European Commission has granted us permission to talk about these projects in public. GEODE and NAVGUARD are the two biggest PRS defence projects, developing a common infrastructure for EU NAVWAR capability, relying on GNSS spectrum surveillance and extending PRS equipment integration platforms to bring us one more step towards a scaled and cost-effective procurement for our PRS end users.”

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1996 soccer game in the Midwest, (Rick Dikeman image)

Nouméa ground station after the flood

A pencil and a coffee cup show the size of NASA’s teeny tiny PhoneSat

Bonus Hotspot: Naro Tartaruga AUV

Pacific lamprey spawning (photo by Jeremy Monroe, Fresh Waters Illustrated)

“Return of the Bucentaurn to the Molo on Ascension Day”, by (Giovanni Antonio Canal) Canaletto

The U.S. Naval Observatory Alternate Master Clock at 2nd Space Operations Squadron, Schriever AFB in Colorado. This photo was taken in January, 2006 during the addition of a leap second. The USNO master clocks control GPS timing. They are accurate to within one second every 20 million years (Satellites are so picky! Humans, on the other hand, just want to know if we’re too late for lunch) USAF photo by A1C Jason Ridder.

Detail of Compass/ BeiDou2 system diagram

Hotspot 6: Beluga A300 600ST

1. Mangrove Tree-Planting Drones
Myanmar (Southeast Asia)

1. Mangrove Tree-Planting Drones
Myanmar (Southeast Asia)
√ For about five years now, a group of villagers in the delta of the Irrawaddy River in Myanmar (also known as Burma) has painstakingly planted 2.7 million mangrove trees with the hopes of beginning to restore an ecosystem that has been disappearing for decades. But this work is rather laborious, and the local nonprofit guiding the work wants to cover a much larger area — so they’re turning drones to help with their large-scale tree-planting project.

The drones, from the startup BioCarbon Engineering, can plant as many as 100,000 trees in a single day, leaving the local community to focus on taking care of the young trees that have already started to grow, according to the company, which has offices in Oxford, U.K., Sydney, Australia and Dublin, Ireland. In September, the company will begin a drone-planting program in the area along with Worldview International Foundation, the nonprofit guiding local tree-planting projects. To date, the organization has worked with villagers to plant an area of 750 hectares, about twice the size of Central Park. The drones will help cover another 250 hectares with 1 million additional trees. Ultimately, the nonprofit hopes to use drones to help plant 1 billion trees in an even larger area.

In the past villages have spent years replanting mangroves along the Irrawaddy River. With drones, their work will now go much faster.

2. Laser-Mapping Landscape Changes
Gargoyle Ridge in the McMurdo Dry Valleys, Antarctica
√ With the help of LiDAR, researchers led by Portland State University (PSU) have publicly released high-resolution maps of Antarctica’s McMurdo Dry Valleys, a unique desert region. The high-resolution maps cover 3,564 square kilometers of the McMurdo Dry Valleys and allow researchers to compare present-day conditions with the last surveys conducted more than a decade ago.

The research project led by PSU, and funded by the United States National Science Foundation (NSF), mapped the area using LiDAR, a remote-sensing method that uses laser beam pulses to measure the distance from the detector to the Earth’s surface. The data, collected by aerial survey missions flown in the Southern Hemisphere summer of 2014-2015, provides detailed imagery of the perpetually ice-free region, where changes, such as rapid erosion along some streams, have been observed in recent years.

The LIDAR maps are publicly available on two NSF-funded facilities: Open Topography, and the Polar Geospatial Center.

The McMurdo Dry Valleys are interesting to a wide range of scientists from biologists to geologists to glaciologists. The valleys are, for example, one of the few places on the massive continent—which is the size of the U.S. and Mexico combined—where bedrock is exposed, allowing geologists to reconstruct the continent’s geological history.

The region also is home to one of NSF’s Long Term Ecological Research sites, which support studies of its unusual habitat, dominated by microbial life, both in the soil and in unique ecosystems under at least one of its glaciers and in several of its highly salty lakes.

Evidence of past glacial advance and retreat is also more easily observed in the Dry Valleys, which provides window into the past behavior of the vast Antarctic ice sheets, the activity of which can influence global sea levels.

3. Fries with Your Drone Delivery?
Reykjavik, Iceland
√ Impatient Icelanders are getting help from Flytrex, an Israeli startup, that just started delivering small orders like takeout food by drone in a partnership with Aha, Iceland’s largest instant delivery platform. The drones, technically hexacopters, were approved by the Icelandic Transport Authority to pick up orders from restaurants and stores on one side of Reykjavik, where Aha has its offices, and fly them to a drop-off point in the suburb of Grafarvogur.

While Flytrex and Aha don’t offer direct store-to-home-delivery, the companies said that even on a trial basis the service would slash waiting times in a city whose bay delivery trucks must skirt to reach their destinations. A drone cuts delivery times by flying across the water to a truck that will complete the delivery.

Flytrex doesn’t make drones but develops autonomous, drone-based delivery systems. The drones can carry packages weighing up to three kilograms, about the size of a mailbox, so they can only handle smaller orders or takeout food.

The single drone now in use can make between 20 and 60 flights day, according to Flytrex, which has developed hardware that is installed on the drone and links it to a cellular network via a SIM card that enables a controller to locate, monitor its speed, altitude and other parameters in real time.

4. Tough Testing for Galileo
Noordwijk, the Netherlands
√ Each Galileo satellite must go through a rigorous test campaign to assure its readiness for the violence of launch, airlessness and temperature extremes of Earth orbit. Each one is dispatched to a unique location in Europe to ensure its readiness prior to launch: a 3,000-square meter cleanroom complex nestled in sandy dunes along the Dutch coast, filled with test equipment to simulate all aspects of spaceflight.

The test centre in Noordwijk – Europe’s largest satellite test site – is part of ESA’s main technical center, but it is maintained and operated on a commercial basis on behalf of the Agency by a private company created for the purpose: European Test Services (ETS) B.V.

ETS has been responsible for supporting many historic test campaigns – including space-certifying Europe’s 20-metric-ton ATV space truck and Envisat, the world’s largest civilian Earth-observing mission. But in terms of scale alone, its work with Galileo is the company’s greatest challenge.

ETS is about to complete its contracts with OHB System AG, covering the environmental test of 22 “Full Operational Capability” Galileo satellites, preceded by the testing of the very first of the first-generation “In-Orbit Validation” Galileo satellites on a previous, separate contract.

The post GNSS Hotspots | September 2017 appeared first on Inside GNSS - Global Navigation Satellite Systems Engineering, Policy, and Design.

A: This is somewhat of a classic GNSS question, but before getting to the answer, let’s seek some clarity about what is being asked. First, by definition, “more” signals or “more” systems must be referenced against some baseline configuration. This is commonly assumed to be a GPS L1 C/A solution, and this assumption is also used herein.

Q: Would you prefer to have more signals or more satellites?

A: This is somewhat of a classic GNSS question, but before getting to the answer, let’s seek some clarity about what is being asked. First, by definition, “more” signals or “more” systems must be referenced against some baseline configuration. This is commonly assumed to be a GPS L1 C/A solution, and this assumption is also used herein.

Second, “more signals” is most commonly interpreted as meaning more frequencies for a given GNSS (e.g., using GPS L1 C/A and L2C), and “more satellites” is typically interpreted as using additional GNSS relative to the baseline case (e.g., GPS and GLONASS, or GPS and Galileo).

Returning back to the original question, as is the case for so many GNSS questions, the answer is: it depends. It depends primarily on the operating environment and the desired positioning accuracy, although other issues may also be critical factors.

By extension, there is no one-size-fits-all answer to this question. Instead, below is a summary of the benefits and challenges of having more signals and having more satellites. I adopted this approach with the hope that readers will better appreciate the trade-offs between the two approaches such that they can make decisions for their specific applications.

More Satellites
Having more satellites is generally most useful when satellite visibility is reduced, such as in deep urban areas. In such cases being able to track signals from multiple GNSS makes it more likely to be able to compute a solution at all. That is, a multi-GNSS approach improves solution availability.

However, even if a single-GNSS solution were possible, having data from multiple GNSS will yield better measurement geometry, or lower dilution of precision (DOP) values. In turn, this results in more precise position estimates.

Having measurements to more satellites also allows the position filter to be more selective about the measurements to be used. For example, ongoing research is investigating how to use carrier to noise-density ratio (C/N₀) information, 3D building models, cameras, or some combination of these to determine when a received signal does not contain a line-of-sight (LOS) component. These satellites can then be rejected leaving, hopefully, only LOS signals—or perhaps multipath-corrupted LOS signals—to derive a more accurate position estimate. To realize the full benefit of such approaches there needs to be enough LOS-based signals available to compute a solution. It follows that the probability of this happening increases as more GNSS are used.

Multi-GNSS approaches also offer accuracy benefits in less benign environments, but to a lesser extent. The reason for this is because in the absence of large errors arising from non-LOS (NLOS) or multipath signals, the main benefit is in terms of improved geometry. But the absence of (many) NLOS signals suggests good sky visibility, in which case even the baseline configuration of a single-GNSS solution will typically have reasonable geometry already.

Since DOP is approximately proportional ¹⁄_√N to where N is the number of satellites used, doubling the number of satellites only provides about 30% reduction in DOP, but tripling the number of satellites reduces DOP by only 42%. Although always beneficial, it is obvious that adding more and more satellites offers diminishing returns.

Unrelated to position accuracy, using more satellites will improve the statistical reliability of the system. In other words, a multi-GNSS solution is more likely (in terms of a probability) to identify a measurement blunder of a certain magnitude than is a single-GNSS solution. Equivalently, a multi-GNSS solution will be able to identify smaller blunders than a single-GNSS solution with the same level of probability.

Although the details of this are beyond the scope of this article, the reason for this is that the magnitude of blunder that can be detected at a given probability level is dependent on geometry which, as described above, is better with multi-GNSS solutions.

On the downside, multi-GNSS solutions need to properly handle differences, if any, in reference ellipsoids (e.g., WGS48 for GPS and PZ-90 for GLONASS) and time scales between the different GNSS. This is not particularly difficult, but ignoring such effects can have significant impacts on positioning performance. Of particular note is that extra states may need to be added to the position filter to properly account for timing differences.

Before moving on, it should be noted that if many satellites are being tracked but the receiver’s processing resources and/or power are limited, it may be desirable and/or necessary to only process a subset of all possible satellites to minimize power consumption. Such situations are likely to be uncommon (and much more enviable than other GNSS-related challenges), but selecting which satellites to process will need to consider the trade-offs between processing complexity, solution precision and statistical reliability.

More Signals
The main benefit of using multiple signals is improved accuracy. This happens in two ways: mitigating ionospheric effects and, to a lesser extent, minimizing multipath effects.

It is well known that ionospheric errors, I, are a function of the carrier frequency of the signal passing through the medium

I(f) = ^{40.3 x TEC}/_{f ²}

where TEC is the total electron count in a square-meter cross-section along the signal path and f is the signal’s carrier frequency. This dispersive quality allows measurements from two signal frequencies to correct for the first-order ionospheric effects. This accounts for typically 99% of the errors, but using three (or more) frequencies allows for the removal higher-order effects.

The downside of this approach is an increase in noise arising from the combination of multiple noisy measurements, for example, noise increases nearly three-fold when using GPS L1 and L2 measurements.

Ionosphere error minimization is the primary benefit of using multiple signals. Practically, however, this benefit is only realized if ionospheric errors represent a significant part of the error budget. This would include situations where multipath effects are limited and/or for real-time kinematic positioning with carrier phase data to improve ambiguity resolution.

For pseudorange-based systems, the benefit of removing the ionosphere will depend largely on the level of measurement noise; if the noise is too high relative to the ionospheric error, then there may be little practical benefits to be realized. That said, increased measurement noise is zero-mean and can be reduced with sufficient averaging/filtering, if the application allows.

Having multiple signals can also be helpful at minimizing the effect of multipath when the LOS signal is present (this contrasts with scenarios where there is multipath but all paths are NLOS). In such cases, the reflected paths are the same for both signals, meaning they both have the same path delay. However, the phase difference between the LOS and NLOS signals at the receiver is generally not the same and so averaging across signals offers some benefits, especially if one of the signals has a large multipath effect.

Of course, if the LOS signal is not present, then there is no benefit since the LOS signal cannot be recovered.

In theory, a multi-signal approach will also improve the statistical reliability of the solution. Practically, these improvements are minimal because GNSS measurement blunders typically arise from multipath and such errors (albeit with different magnitudes, as discussed above) are present on all signals from a given satellite. With this in mind, it should be intuitively obvious that using a blundered measurement to detect a blunder in another measurement does not typically yield the desired result.

The final benefit of multiple signals is the improved resilience to interference. This arises from the simple fact that jamming two or more signals in different bands is inherently more difficult than jamming a single frequency. If the additional signals also have ranging codes with wider bandwidths and/or different auto-correlation properties, this can further improve interference mitigation—this latter benefit would therefore be realized for multi-GNSS systems as well.

The challenges of using multiple signals are two-fold. First, the receiver will need two front-ends, which in turn requires more power. This will be especially important for power-sensitive applications. Second, inter-frequency biases need to be properly accounted for. Most receivers already calibrate these but this is nevertheless a source of error.

Summary
Table 1 (at the top of this article) summarizes the benefits and challenges of each of the two scenarios discussed above. Broadly speaking, if you have to choose between the two approaches, multi-GNSS systems will be most beneficial in signal-obstructed the receiver is not ideally located on the object being positioned (e.g., inside a car or inside a bag). In contrast, multi-signal systems will typically be most useful for improving accuracy when signal visibility is less of a concern. areas such as urban canyons or when

That said, GNSS applications vary widely in terms of their requirements, operating environments, or both. It is the responsibility of the system designer to consider the benefits and challenges of the different approaches in order to maximize performance for their application.

Of course, the most desirable option would always be to use a multi-signal, multi-GNSS system, if possible.

The post Would you prefer to have more signals or more satellites? appeared first on Inside GNSS - Global Navigation Satellite Systems Engineering, Policy, and Design.

As described in the November-December issue of Inside GNSS, “Interference Localization from Space,” radio frequency interference causes the satellite industry to lose millions of dollars per year due to detrimental effects, ranging from a degradation in the quality of service to the complete loss of service.

As described in the November-December issue of Inside GNSS, “Interference Localization from Space,” radio frequency interference causes the satellite industry to lose millions of dollars per year due to detrimental effects, ranging from a degradation in the quality of service to the complete loss of service.

In an effort to combat this, Vienna, Austria-based Siemens Convergence Creators has announced its new Satellite Geolocation Service, designed to enable satellite and service operators to localize satellite signal interference worldwide.

For satellite operators and users, including the GNSS community, the ability to rapidly identify and mitigate interference — intentional or not — is crucial to protecting the core functionality of their assets and service operations.

According to a statement by the European Space Agency (ESA), which supported the development of the geolocation system, SIECAMS ILS ONE works by analyzing the signal distortions primarily caused by satellite movement, atmospheric, or weather influences and other environmental factors. By comparing such signal distortions of the interference signal with known signals, ILS ONE is able to identify the precise location of the interference source.  

Up to now, interference geolocation systems required having two geostationary satellites in close proximity to each other in order to obtain sufficient crosstalk for reliable geolocation signal processing. According Siemans Convergence Creators, SIECAMS results in a significant improvement in the resolution of interference issues compared with traditional satellite-interference localization systems.

“The SIECAMS single-satellite solution is a real game-changer for the satellite industry,” says Stephane Pirio, ESA Technical Officer for the activity. “It is much cheaper than traditional geolocation systems and this makes it particularly attractive for small- and medium-size satellite operators.”

SIECAMS ILS ONE has been very successfully used by Eutelsat since early 2016.

Siemens Convergence Creators has made substantial investments towards the development of tools for satellite interference mitigation in the last decade within the framework of its SIECAMS product line. SIECAMS currently comprises the carrier-monitoring and interference-detection tool SIECAMS CMS, the carrier-ID detection tool SIECAMS CID, the geolocation system SIECAMS ILS, and the single-satellite geolocation system, SIECAMS ILS ONE.

Until now, the company says, satellite operators had to invest in high-quality geolocation tools and personnel training to enable their own staff to identify, locate, and reduce or eliminate sources of interference in order to avoid potential damage claims and the risk of losing customers. Even so, locating the origin of interference may take days, weeks, or even months.

The localization of satellite interference works worldwide because Siemens Convergence Creators’ Satellite Geolocation Service offers coverage of practically the entire inhabited landmass on Earth.

The Satellite Geolocation Service went into operation on January 9 and can be ordered on demand for individual interference events, or via yearly subscription that includes a contingent of interference localization instances.

Part 2 of the Working Papers on satellite-based geolocation of interference can be found in the January-February issue of Inside GNSS.

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The U.S. Air Force Space and Missile Systems Center (SMC) says it continues to work on GPS III ceramic capacitor testing and plans to have an updated launch schedule published late next month.

As Inside GNSS reported, the first GPS III satellite’s delivery, originally scheduled for August, was delayed by four months because of a Lockheed Martin subcontractor’s failure to test a ceramic capacitor.

The U.S. Air Force Space and Missile Systems Center (SMC) says it continues to work on GPS III ceramic capacitor testing and plans to have an updated launch schedule published late next month.

As Inside GNSS reported, the first GPS III satellite’s delivery, originally scheduled for August, was delayed by four months because of a Lockheed Martin subcontractor’s failure to test a ceramic capacitor.

"GPS III-01 remains on track for a spring 2018 launch. The GPS III program office continues to resolve final issues and plans to close on an available-to-launch date around 31 January 2017," said Lt. Gen. Samuel Greaves, SMC commander and Air Force program executive officer for space.

During Lockheed Martin’s navigation payload testing, they discovered a ceramic capacitor that had not been properly qualified per the program’s approved parts control plan, the company said. "Upon discovering the issue, we took immediate corrective action with the payload provider to qualify the capacitor. The capacitor qualification test forecast completion is [in] December," said Chip Eschenfelder, a Lockheed Martin spokesman, in response to an Inside GNSS query in September.

Harris Corporation, which provides the ceramic capacitor part, said it is working with Lockheed Martin and the Air Force to remedy the situation. Ellen Mitchell, a spokeswoman for Harris, said that the capacitor was among more than 28,000 parts used in the payload. "It is part of a legacy Exelis program that Harris acquired last year," she told Inside GNSS.

Colonel Steve Whitney, U.S. Air Force GPS program manager, told Bloomberg that the ceramic capacitor testing should have been completed five years ago.

GPS III is the next generation of GPS satellites, which will introduce new capabilities to meet the higher demands of both military and civilian users, the Air Force said. The satellite is expected to provide improved anti-jamming capabilities as well as improved accuracy for precision navigation and timing.

GPS III will incorporate the common L1C signal, which is compatible with the European Space Agency’s Galileo global navigation satellite system and complements current services with the addition of new civil and military signals.

In April, the Air Force awarded an $82.7-million contract to Space Technologies Corporation (SpaceX) for GPS III Launch Services. The Air Force characterized the launch contract as "the first competitively sourced National Security Space (NSS) launch services contract in more than a decade."

As Inside GNSS reported, President Obama signed the National Defense Authorization Act (NDAA) for Fiscal Year 2017, a $619-billion bill with a number of provisions affecting satellite navigation. The NDAA authorizes all of the spending the White House requested for the various elements in the GPS program, including $141.89 million for GPS III satellite development and $34.06 million for GPS III procurement.

The actual funding for FY17 in the form of an appropriations bill has yet to be approved, however — although that is not a bad thing for the GPS program. Congress passed a continuing resolution, signed into law December 10, which allocates money at FY16 levels through April 28, 2017.

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The CYGNSS spacecraft rode into orbit onboard an Orbital ATK air-launched Pegasus XL rocket. Orbital ATK’s modified L-1011 aircraft deployed the Pegasus XL and its CYNGSS payload at 39,000 feet, the agency said.

NASA successfully launched eight Cyclone Global Navigation Satellite System (CYGNSS) microsatellites this morning (December 15, 2016) from Cape Canaveral Air Force Station in Florida.

The CYGNSS spacecraft rode into orbit onboard an Orbital ATK air-launched Pegasus XL rocket. Orbital ATK’s modified L-1011 aircraft deployed the Pegasus XL and its CYNGSS payload at 39,000 feet, the agency said.

"We think everything looks really, really good. About three hours after launch we’ll attempt first contact, and after that, we’ll go through a series of four contacts where we hit two [observatories] each time, checking the health and status of each spacecraft," said John Scherrer, CYGNSS project manager at the Southwest Research Institute, in a NASA blog.

NASA said it had to cancel two previous launch dates this week because of a hydraulic system malfunction that operates the mechanism to release the Pegasus rocket from the L-1011 aircraft and a software problem.

As Inside GNSS reported earlier, CYGNSS will measure the surface roughness of the world’s oceans. Mission scientists will use data collected to calculate surface wind speeds, providing a better picture of a storm’s strength and intensity, and storm surges, which include walls of water that do the most damage when hurricanes make landfall.

While in orbit, the satellites will receive both direct and reflected signals from GPS satellites.

During the two-year mission, the eight CYGNSS microsatellites will fly in formation about 316 miles above Earth’s surface, focusing on the tropics and studying wind speeds and intensification of tropical cyclones such as hurricanes, according to the NASA blog.

Other weather satellites cannot penetrate heavy rain in a hurricane’s eyewall to gather intense inner core storm data, but CYGNSS can, NASA said. In addition, CYGNSS small satellite observatories will monitor surface winds over the oceans across Earth’s tropical hurricane-belt latitudes, the agency said.

The University of Michigan’s Space Physics Research Laboratory leads the overall mission in partnership with the Southwest Research Institute, which heads up the science investigation. The Earth Science Division of NASA’s Science Mission Directorate oversees the mission.

NASA expects receive CYGNSS data as early as next week, said Chris Ruf, CYGNSS principal investigator from the University of Michigan, in the agency blog.

There will be a one- to two-month commissioning phase in which each microsatellite will be checked out and maneuvered into its final position, NASA said. The agency expects the CYGNSS constellation to be fully operational for the 2017 hurricane season.

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The U.S. Air Force has approved Lockheed Martin’s current GPS satellite ground control system upgrade to enable it to operate with more powerful and accurate GPS III satellites, the company said.

The Air Force’s Critical Design Review (CDR) for the Contingency Operations (COps) contract, completed on November 17, allows Lockheed Martin to proceed with the modification of the existing Architecture Evolution Plan (AEP) Operational Control Segment. The AEP, maintained by Lockheed Martin, controls the 31 GPS IIR, IIR-M and IIF satellites in orbit.

The U.S. Air Force has approved Lockheed Martin’s current GPS satellite ground control system upgrade to enable it to operate with more powerful and accurate GPS III satellites, the company said.

The Air Force’s Critical Design Review (CDR) for the Contingency Operations (COps) contract, completed on November 17, allows Lockheed Martin to proceed with the modification of the existing Architecture Evolution Plan (AEP) Operational Control Segment. The AEP, maintained by Lockheed Martin, controls the 31 GPS IIR, IIR-M and IIF satellites in orbit.

Lockheed Martin said that the COps modifications allow the AEP to support the new GPS Block III satellites by enabling them to perform their positioning, navigation and timing mission, once they are launched. COps is envisioned as a temporary gap filler prior to the GPS constellation’s transition to the next generation Operational Control System (OCX) Block 1, the company said.

"The GPS constellation is a valuable asset to our warfighters, our nation and the world. This risk-reduction effort ensures the Air Force has the ability to maintain the constellation at full strength," said Mark Stewart, vice president of Lockheed Martin’s Navigation Systems mission area. "We are here to support the Air Force and the GPS III program any way we can."

In February, the Air Force awarded Lockheed Martin the $96 million COps services and supplies contract. The government approved the company’s proposed ground system modification during a Preliminary Design Review on May 11, the company said.

As Inside GNSS reported, under a separate contract in October, Lockheed Martin completed the Commercial Off-the-Shelf (COTS) Upgrade no. 2 (CUP2) project, which is part of a multi-year plan to refresh the AEP’s technology and enhance the system’s ability to protect data and infrastructure, the company said. Lockheed Martin said CUP2 is now fully operational and managing the current GPS constellation.

In September, Lockheed Martin received a $395 million U.S. Air Force Space and Missile Systems Center contract option to build two additional GPS III satellites. The contract option calls for long-lead and production hardware to manufacture GPS III space vehicles (SVs) 9 and 10.

The government plans to compete future purchases of GPS III satellites beginning with the GPS III SV 11. This future competition will maintain the current technical GPS III baseline, and will add additional hosted payloads to increase system accuracy, search and rescue capability, and universal S-Band compatibility, the Air Force said.

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The satellites, launched from Europe’s Spaceport in French Guiana on May 24, went through lengthy testing that included receiving and uplinking signals through specialized antennas, ESA said. Some of the tests included navigation and search and rescue payloads methodically switched on, the agency said.

After months of testing, the European Space Agency (ESA) has announced that Galileo satellites 13 and 14 are transmitting healthy navigation signals and ready to relay distress calls to emergency services.

The satellites, launched from Europe’s Spaceport in French Guiana on May 24, went through lengthy testing that included receiving and uplinking signals through specialized antennas, ESA said. Some of the tests included navigation and search and rescue payloads methodically switched on, the agency said.

The test phase was conducted at both the Galileo Control Center in Oberpfaffenhofen, Germany, and from ESA’s Redu Center in Belgium. The Oberpfaffenhofen and Redu centers were linked for the entire test campaign, allowing ESA to compare Galileo signals with satellite telemetry in near-real time, the agency said.

The test campaign measured the accuracy and stability of the satellites’ atomic clocks, which is essential for the timing precision to within a billionth of a second as the basis of satellite navigation, ESA said.

Both satellites were visible above the Redu facility for three to nine hours each day, allowing personnel to schedule tests accordingly, ESA said.

The next four satellites, launched on November 17 from French Guiana, are beginning the same in-orbit testing activity, ESA said. The agency hopes to have the four satellites operational in the spring.

Early in 2017, ESA plans to development new concepts for on-board precise orbit determination (POD) for satellites in several orbits using GNSS and similar techniques. Some of the testing will include identification and development of key drivers and requirements for new on-board POD concepts, according to a presentation by Werner Enderle, European Space Operations Center’s (ESOC) head of navigation support office, at this week’s PNT Advisory Board meeting in California.

The agency also announced that a Galileo next-stage navigation research program received strong backing recently during European Union (EU) meetings in Switzerland. The agency said that while European Geostationary Navigation Overlay Service (EGNOS) and Galileo "are on a steady footing," their future construction and evolution will be supported by EU’s Global Navigation Satellite System and Horizon 2020 programs.

ESA said they also received strong EU support for its Navigation Innovation and Support Program (NAVISP), which combines EGNOS and Galileo expertise to future positioning, navigation, and timing (PNT) challenges, ESA said.

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NASA plans to launch the Cyclone GNSS (CYGNSS) hurricane mission aboard a Pegasus XL rocket on December 12 from Cape Canaveral Air Force Station in Florida. CYGNSS, which is NASA’s first Earth science small-satellite constellation, will help improve hurricane intensity, tracking, and storm surge forecasts, the agency said.

CYGNSS, a constellation of eight microsatellites shot into orbit on a single launch vehicle, will measure the surface roughness of the world’s oceans. Mission scientists will use data collected to calculate surface wind speeds, providing a better picture of a storm’s strength and intensity, and storm surges, which include walls of water that do the most damage when hurricanes make landfall.

While in orbit, the satellites will receive both direct and reflected signals from GPS satellites.

"As a constellation of eight spacecraft, CYGNSS will do what a single craft can’t in terms of measuring surface wind speeds inside hurricanes and tropical cyclones at high time-resolution, to improve our ability to understand and predict how these deadly storms develop," said Thomas Zurbuchen, NASA Science Mission Directorate associate administrator.

Other weather satellites cannot penetrate heavy rain in a hurricane’s eyewall to gather intense inner core storm data, but CYGNSS can, NASA said. In addition, CYGNSS small satellite observatories will monitor surface winds over the oceans across Earth’s tropical hurricane-belt latitudes, the agency said.

The University of Michigan’s Space Physics Research Laboratory leads the overall mission in partnership with the Southwest Research Institute, which heads up the science investigation. The Earth Science Division of NASA’s Science Mission Directorate oversees the mission. "Today, we can’t see what’s happening under the rain," said Chris Ruf, University of Michigan professor and principal CYGNSS mission investigator. "We can measure the wind outside of the storm cell with present systems. But there’s a gap in our knowledge of cyclone processes in the critical eyewall region of the storm, a gap that will be filled by the CYGNSS data. The models try to predict what is happening under the rain, but they are much less accurate without continuous experimental validation."

NASA said that the CYGNSS satellites, originally scheduled for launch in October and November, have successfully completed functional and environmental testing at the Southwest Research Institute in San Antonio, Texas. The tests simulate harsh space and launch environments.

According to the Southwest Research Institute, all of the spacecraft were placed in a vacuum chamber and cycled through extreme hot and cold temperatures they will face in orbit.

CYGNSS will carry Surrey Satellite Technology’s (SSTL) Space GNSS Receiver-Remote Sensing Instrument (SGR-ReSI) to measure ocean roughness. SGR-ReSI is already onboard the TechDemSat-1, a small technology demonstration satellite launched by SSTL in 2014. With support from the European Space Agency (ESA), SSTL and the United Kingdom’s National Oceanography Center (NOC) are working with TechDemoSat-1 data to improve measurement calibration, new techniques, and applications, the company said.

SGR-ReSI was developed by SSTL to calculate TechDemoSat-1’s position and speed by measuring ranges and trilaterating its position from GNSS satellites. The SGR-ReSI also carries a high-gain nadir antenna to use with GNSS reflectometry for signal collection and measurement, the company said.

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In September NOAA, through the government’s Commercial Weather Data Pilot program, awarded contracts to San Francisco, California-based Spire Global ($370,000) and GeoOptics ($695,000), of Pasadena, California, to provide RO data. This data will be used to assess whether commercially provided information can be incorporated into the agency’s weather models.

The National Oceanic and Atmospheric Administration (NOAA) will purchase data from small commercial satellites to expand its GNSS radio occultation (RO) efforts to better predict weather.

In September NOAA, through the government’s Commercial Weather Data Pilot program, awarded contracts to San Francisco, California-based Spire Global ($370,000) and GeoOptics ($695,000), of Pasadena, California, to provide RO data. This data will be used to assess whether commercially provided information can be incorporated into the agency’s weather models.

The RO technique has been around for a long time, taking advantage of the effects of electrical energy and moisture in the atmosphere on GNSS signal propagation. The GPS signals bend a bit as they skim through the atmosphere; a deflection that is a function of the density of the atmosphere. The time it takes for the signal to travel the now-longer path around the curve of the planet can be used to calculate atmospheric properties, such as temperature, pressure, humidity and electron density.

With its Stratos product, Spire gathers RO data from 10 low Earth orbit (LEO) small, or microsatellites with multiple sensors, tracking GPS signals providing 3.65 atmospheric profiles per year, according to the company. GeoOptics will begin launching its LEO cubesat constellation, CICERO, in early 2017. When RO data is combined with that from polar-orbiting weather satellites, NOAA believes it can make better weather forecasts.

Both Spire and GeoOptics will begin providing GNSS RO data to NOAA by April 30, 2017, the agency said. NOAA’s National Environmental Satellite, Data, and Information Service (NESDIS) will analyze the data and issue a report in early 2018.

"[NOAA’s] models take data from a number of sources including radiosondes, land-based stations, and satellites," said Sandy MacDonald, Spire’s director for numerical weather prediction. "GPS RO data delivers a very accurate and detailed sounding of temperature and moisture from the upper atmosphere into the lower atmosphere. About 40 percent of the soundings make it to the lowest layer of the atmosphere, the boundary layer. GPS RO data is exceptionally useful for making bias corrections in the full atmosphere."

NOAA already uses GNSS RO data through the six-satellite COSMIC constellation, which is a joint satellite program with Taiwan. The agency has requested more federal funding for COSMIC-2 follow-on satellites.

Currently, Spire’s satellites collect RO data in a pre-production capacity, said MacDonald, a 40-year NOAA veteran who leads Spire’s RO efforts in Boulder, Colorado. "Unlike some forms of data, GPS-RO requires processing for it to be useful in forecasting. This September, at the International Radio Occultation Working Group, we revealed the first commercially collected and processed GPS-RO profiles," he said. "The biggest hurdles to getting the data is access to on-time rocket launches. We have the single most aggressive launch schedule in the industry with over 70 satellites manifested over the next year but delays on the launch pad affect how quickly we get access to this data."

Congressional Push for Commercial Data
While Congress approved $3 million for Commercial Weather Data Pilot program, the effort was initiated through the Weather Research and Forecasting Innovation Act. The measure, sponsored by two Oklahoma representatives, Frank Lucas and Jim Bridenstine, both Republicans, calls for commercial data for weather monitoring purposes.

U.S. Representative Lamar Smith, R-Texas, who is chairman of the House Committee on Science, Space, and Technology, said it was a good thing that NOAA is acquiring private sector weather data. "In the face of looming data gaps and continual delays with our governmental satellite systems, the private sector can provide data to better predict weather and protect American lives and property," he said. "In the face of real threats, NOAA needs to address its shortfalls and think beyond government weather systems by making further awards under the [Commercial Weather Data Pilot program].

"We see a future with small satellites delivering data of the same quality that required large satellites and much greater cost in the past," MacDonald said. "We’ve already demonstrated that small satellites are most effective when collecting large amounts of data through Spire’s ship tracking product. Similar to ship tracking where frequent updates are important, spatial density is an important factor in the usefulness of GPS RO data. By launching many small satellites, they’re able to capture an exceptional number of occultations in comparison to smaller number of traditional satellites."

Small satellites have the attention of the White House Office of Science and Technology Policy (OSTP). A new OSTP initiative, "Harnessing the Small Satellite Revolution," calls for NASA, the Defense Department (DoD), Commerce Department, and other agencies to promote government and private small satellite use.

In addition to NOAA’s weather efforts, small satellites will be used for remote sensing, communications, science, and space exploration, the White House said. NASA will fund as much as $30 million in small satellite data purchases, including $25 million for nongovernment spacecraft constellations. NASA also intends to purchase such Earth science observation data as moderate-resolution land imaging and RO data.

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