Global Navigation Satellite Systems Engineering, Policy, and Design
The U.S. Department of Defense awarded a $1.7 million contract to Orolia Defense and Security for multiple BroadSim advanced GPS simulator systems for testing facilities and field test assets.
By Inside GNSS
A new magnetic anomaly navigation technique (MAGNAV), researched by the Air Force Institute of Technology (AFIT), will get its wings tested aboard F-16 fightercraft this September. In an effort seeking alternatives to GPS and GNSS, MAGNAV sensors and software will be flown on Air Force Test Pilots School (AFTPS) F-16s over a test range adjacent to Edwards Air Force Base in Nevada.
By Inside GNSS
The U.S. Air Force updated the GPS Standard Positioning System (SPS) Performance Standard (PS) in mid-April, 2020, the first new Performance Standard document since 2008. It includes mention of and pre-Initial Operating Capability (IOC) performance standards for the new civil GPS signals L2C and L5 for the first time. In another new feature, the document mentions “expanded capabilities which allow the total size of operational constellation to grow beyond the previous maximum of 32 Navstar satellites” for “more robust constellation availability to enhance the overall SPS SIS performance.”
By Inside GNSS
The Federal Communications Commission ignored a technical standard defining radio-frequency interference. The five commissioners licensed powerful terrestrial broadcast next to the satellite band, exposing national defense and critical infrastructure to harm.
The Federal Communications Commission should really consider updating its motto. “Firm, fast, flexible, and fair” has a bit of an old-fashioned ring. As mottos go, it fails to keep up with the times.
By Alan Cameron
The European Space Agency (ESA) awarded two contracts to Thales Alenia Space concerning system evolution of the European Geostationary Navigation Overlay Service (EGNOS).
By Inside GNSS
Britain’s own satellite navigation system, envisioned to fill the country’s Galileo void created by Brexit, may never see the light of day. Government officials don’t want to spend tax revenues to meet projected increasing costs.
By Inside GNSS
The MEMS-based inertial measurement unit (IMU) represents the single biggest positioning and navigation advance of the last 20 years. That assertion is made during the first of three panels in the webinar “Inertial Technology for Robotics, UAVs and other Applications,” freely available on May 6. The 1.5 hour presentation examines how this breakthrough plays in the fields of autonomy, high dynamics and challenging environments, including on the frontiers of space.
Three experts takes a close-up look at contemporary and emerging inertial sensor technologies and applications, from the laboratory to the factory to the field. Register here to attend. The webinar is sponsored by Sensonor.
MEMS (micro-electromechanical sensors) make possible a miniaturization of size, weight, power requirements and cost never thought achievable before. When MEMS inertial navigation pairs with GPS for navigation, the key factor is the error budget of each sensor and how that plays into the accuracy of the solution. Attendees will learn how the new inertial sensors’ reduced error budgets translate into higher system performance.
The presentation begins with the current state of the inertial art, delivered by a recognized expert. The second speaker describes a high-accuracy tactical-grade inertial measurement unit (IMU) with increased accelerometer performance to support demanding guidance and navigation applications.
This knowledge is taken to the field to examine the IMU’s role in successful satellite launch missions during the third panel. The attitude determination and control system (ADCS) rises to the challenge of an extremely demanding environments and set of requirements. A satellite moving at a speed of 7,500 meters/second over ground requires precise maneuvering, stabilization and point in order to obtain imagery at 1-meter resolution.
Questions from the audience are actively encouraged and will be addressed by the three speakers in the final portion of the webinar.
Webinar speakers:
Ralph Hopkins is a Distinguished Member of the Technical Staff and Group Leader in the Positioning Navigation and Timing (PNT) Division at Draper, a leading research & development organization. He is responsible for the design and development of inertial instruments and sensors. Ralph has served as Technical Director of advanced inertial instrument development programs including strategic, navigation and tactical grade gyroscopes and accelerometers. He holds an ME in Engineering Mechanics from Columbia University, and an MS in Engineering Management from The Gordon Institute of Tufts University.
Reidar Holm is a Product Development Manager at Sensonor, a producer and developer of high-precision, light-weight gyros and IMUs. He works MEMS R&D and design, ASIC design, low-stress package design, system design, assembly and calibration, and high-volume production for automotive, MEMS pressure sensors, accelerometers, gyros and IMUs. He has a Degree in Electrical Engineering and Electronics from University of Manchester Institute for Science and Technology (UK) in 1982.
Ryan Robinson is the Lead Guidance, Navigation and Control Engineer at LeoStella, a small satellite design and manufacturing company, He is responsible for the design, development, test, and delivery of ADCS subsystems on LeoStella satellites. He received a Ph.D. in Aerospace Engineering from the University of Maryland, College Park. Technical areas of interest include attitude determination and control systems design, sensing and actuation, nonlinear dynamics, and autonomy.
Register here for the free webinar, “Inertial Technology for Robotics, UAVs and other Applications.” The webinar will also be available for subsequent download, for those registrants unable to attend at the appointed time.
By Inside GNSS
In its order allowing Ligado Networks to use satellite frequencies for on-the-ground wireless, the Federal Communications Commission set conditions on the firm’s operations, but only at the very tail end. Those conditions are there to help protect GPS receivers from interference — interference the FCC acknowledges as being quite possible.
By Dee Ann Divis
Though the FCC approved Ligado Networks’ request to use satellite frequencies to support terrestrial 5G, opposition to the move remains firm as everyone waits to see what kind of measures are included in the final decision to protect GPS from interference.
By Dee Ann Divis
The five members of the Federal Communications Commission voted unanimously to approve a request by Ligado Networks to use satellite frequencies neighboring those used by GPS to broadcast from ground antennas for 5G, the agency announced Monday morning.
By Dee Ann Divis
“Ligado’s planned usage will likely harm military capabilities, particularly for the U.S. Space Force, and have major impact on the national economy,” two ranking Senators and a Representative wrote. The timing could not be worse, they said to allow what “is fundamentally a bad deal for America’s national and economic security.”
By Dee Ann Divis
The U.S. Air Force 2nd Space Operations Squadron has put the last operational GPS IIA satellite, SVN 34, into disposal cycle for April 13 to 20. This is effectively end of life, or space hospice if you will, for a satellite that has outlived its 7.5 year design span by 19 years.
The rite of passage brings to a close a 26.5-year era in which the IIA generation carried the gold standard of positioning 20,200 km (12,550 miles) above the Earth, circling the globe twice a day.
Nineteen Block IIA satellites, slightly improved versions of the Block II series (the first full scale operational GPS satellites), were launched from November 26, 1990 until November 6, 1997. The satellites were built by Boeing, formerly Rockwell Corporation. They broadcast the L1 C/A signal for civil users and the L1/L2 P(Y) signals for military users.
SVN-34, the last of its generation, was removed from service October 9, 2019 but kept on as part of the constellation as a decommissioned, on-orbit spare until April 13.
In the disposal process, “We push the satellite vehicle to a higher, less congested, ‘disposal orbit’ to eliminate the probability of collision with other active satellites,” said Capt. Angela Tomasek, 2SOPS GPS mission engineering and analysis flight commander. “[Then,] the vehicle is put into a safe configuration by depleting the leftover fuel and battery life and shutting off the satellite vehicle transmitters so no one else can access the satellite in the future.”
“As we continue to manage the influx of GPS III and maintaining other vehicles in a residual status, we have to be cognizant of effective risk management,” Tomasek continued. “As SVN-34 continued to age, we had to manage its aging components and likelihood of having a critical malfunction. We are at a stage where we are confident in the robustness of the overall GPS constellation to remove the last remaining IIA vehicle.”
Once SVN-34 arrives in its final orbit, 2 SOPS will hand over full tracking responsibility to the 18th Space Control Squadron at Vandenberg AFB, California, where it will be treated and catalogued like every other space object, on April 20.
“This disposal marks the end of an era in GPS history,” said Lt. Col. Stephen Toth, 2nd SOPS commander. “There are senior leaders and long-time contractors [who] launched and operated the IIA satellites at the beginning of their careers [who] are now here to see it end. It is an opportunity to reflect on the legacy and heritage of 2 SOPS and GPS to see how far we have come.”
By Inside GNSS
