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| Whoa, GAO! Full Report Worth the Read
| | My assessment of the GAO report has changed markedly since I read the full report. To say that the Executive Summary does not do the report justice is a gross understatement. Most of my objections concerning the Executive Summary were answered in the full-length report. Therefore, I highly recommend that you read it. However, as to the recommendations: It took the GAO 19 months to conduct a study that recommended no more than the status quo. That's right, both of the GAO's major recommendations have been in place for several years. | |  |
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| Air Force Polls Receiver Makers for Solutions to Satellite Problems
| | | The U.S. Air Force GPS Wing seeks comments from receiver manufacturers regarding the SVN-49 signal anomaly and the Air Force’s proposed solution. The Air Force has been investigating the cause and effects of signal distortions, observed as an elevation-dependent bias in ranging measurements, from the GPS IIR-20(M) spacecraft launched on March 24, 2009 and not yet set operational. As recently as June 19, the GPS Wing outlined solutions it planned to implement to compensate for the pseudorange errors, but now it states that "it is not possible for the Air Force to evaluate the myriad of civilian products and applications. Your help is urgently requested to […] evaluate […], conduct tests […], and provide recommendations and advice to the Air Force." |
| | The SVN-49 Story: What Went Wrong, How It Got Found, and Fixed
| | | During a very reassuring teleconference today with Colonel David Madden (GPSW/CC) and Colonel David Buckman (AFSPC - GPS Command Lead), we learned the true story of exactly what happened to SVN-49 , aka IIR-20(M), launched March 24, and why it has not been set to a healthy status. This teleconference should put an end to all the speculation concerning SVN-49 and its future status. In sum, there is nothing wrong with the L1, L2, or L5 signal transmitters, and they will not have to undergo expensive re-testing. |
| | Latest GPS Satellite Early Orbit Checkout Extended
| | | The U.S. Air Force is investigating the cause and effects of signal distortions observed from the GPS IIR-20(M) spacecraft launched on March 24, 2009. Routine early orbit checkout procedures determined that GPS IIR-20(M) signals were inconsistent with the performance of other GPS IIR-M satellites. The signal distortion was initially observed as an elevation-dependent bias in ranging measurements from GPS monitor stations. |
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 | Assessing the Spoofing Threat
| | | A portable spoofer implemented on a digital signal processor mounts a spoofing attack, characterizes spoofing effects, and suggests possible defense tactics. GNSS users and receiver manufacturers should explore and implement authentication methods against sophisticated spoofing attacks. |
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 | | Leadership Talks — Anomaly Response
| | Don Jewell, contributing editor for GPS World's military and government section, interviewed Col. Mark Crews (pictured above), chief engineer at the GPS Wing, U.S. Space Missile Command, regarding GPS anomalies that occurred in October 2007 that resulted in a great deal of concern in the international user and monitoring community. | | |
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 | Monocular SLAM
| | | GPS-denied navigation indoors, underground, on moving reference frames, and in urban canyons can be achieved in a practical approach suitable for use by the warfighter or emergency responder, using robotic vision algorithms and coupled MEMS-based dead-reckoning modules. Current robotic vision algorithms such as Simultaneous Location and Mapping (SLAM) are throughput-intensive and are not practical for the dismounted user. The MEMS provides excellent instantaneous sensor pointing information that reduces the SLAM processing requirements significantly. |
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 | Navigation in a Nugget
| | | The Navigation Nugget, first GPS receiver in the world to incorporate a chip-scale atomic clock, will transform designs for the future, enabling warfighters and warfighting platforms to navigate in waters and terrains that can be unattainable with current standalone GPS receivers. |
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 | Education: Students Launch Sensor into Space
| | | Who says space exploration is only for nations or corporations? This summer, students from Oklahoma State University's Radiation Physics Laboratory built and launched a cosmic radiation detector with GPS, which touched the edge of outer space. |
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 | Make Every Shot Count
| | | GPS technology helped the U.S. Air Force take out al-Qaeda leader Abu Musab Al-Zarqawi in a June 14 airstrike. "GPS provides the precision timing and navigation absolutely instrumental in both protecting our troops on the ground and taking out the bad guys," said an Air Force brigadier general. |
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