CSR, SiRF Complete Merger

CSR plc and SiRF Technology Holdings Inc., have completed the merger between SiRF and a wholly owned subsidiary of CSR.

GPS Wing Seeks Manufacturer, User Feedback on SVN49 Signal Anomaly, Solution

The GPS Wing is reaching out to receiver manufacturers and the user community to gather comments on the SVN49 signal anomaly and the Air Force’s provisional solution to the problem.

Despite earlier news reports suggesting that the problem, which has kept the latest GPS satellite from being declared operational, was on its way to being solved, a GPS Wing spokesperson characterized the remedy of altering the satellite’s broadcast orbital position (ephemeris) and time as only a “partial fix.” Indeed, high-precision dual-frequency users, such as those in the International GNSS Service, may continue to encounter difficulties in handling the SVN49 signal.

FAA Awards New WAAS Receiver Contract to NovAtel

GNSS manufacturer NovAtel Inc., of Calgary, Alberta, Canada, has received a new contract from the Federal Aviation Administration (FAA) to develop the next-generation GPS Wide Area Augmentation System (WAAS) reference receiver (the “GIII” receiver). The three-year contract is worth up to US$9.7million.

Saving GPS SVN49: Tweaking Satellite Ephemerides and Time

When GPS reference receivers at the European Space Operations Center (ESOC) detected a 150-meter error in the broadcast ephemerides (orbital position) for the latest GPS satellite — Space Vehicle Number 49 or SVN49 — scientists there assumed that a problem had arisen with the spacecraft’s navigation payload.

After all, coupled with an apparent 500-nanosecond clock error, the ephemerides could produce many kilometers of errors for navigation receivers.

Saving SVN49

Due to its news value, this article is available as a 375 k downloadable pdf in advance of the July-August 2009 issue publication.

Air Force May Be Able to Fix Problem with Latest GPS Satellite

U.S. Air Force officials have confirmed that signal anomalies on the latest GPS satellite — IIR-20(M), also identified as SVN49/PRN01 — are related to the interface to the new L5 payload also on board.

But the problem appears fixable.

The spacecraft has remained is still in early orbit checkout since its launch on March 24 and has not been introduced into the operational constellation.  

A dedicated response team of Air Force and contractor experts are wrapping up their investigation of the cause of the L1 signal anomalies, which were detected on April 9. The signal distortion was initially observed as an elevation-dependent bias in ranging measurements from GPS monitor stations.

eLoran: The Never-Ending Story?

To say that enhanced Loran (eLoran) has been an on-again off-again program would give short shrift to multiple generations of official ambivalence about the proposed backup for GPS.

The latest chapter began on June 4 when Senator Maria Cantwell (D-Washington) introduced S. 1194, the Coast Guard Authorization Act for Fiscal Years 2010 and 2011 (FY2010/11).

Among other details, the measure directs the Secretary of Transportation to continue the Loran system until a plan has been drawn up and implemented to transition the program to eLoran.

Applanix Introduces New Aerial Digital Photogrammetric System

Applanix
has introduced the POSTrack 410 flight management and direct
georeferencing system designed for use with the latest generation of
medium-format airborne digital photogrammetric camera.

The
POSTrack 410 incorporates Applanix's POS AV GNSS-inertial navigation
system (INS) and POSPac Mobile Mapping Suite (MMS) office software,
featuring the  IN-Fusion technology and SmartBase module. This system
can process both GPS and GLONASS signals as well as those from
satellite-based augmentation systems.

Changes in Store for U.S. Military GPS Equipment Development and Acquisition

Development and acquisition of military GPS user equipment (MGUE) are taking on new dimensions across the board — institutionally, procedurally, and technologically.

Along the way, the changes could redefine relationships within the Department of Defense (DoD) and between the agency and industry.

At the agency level, a proposal is forthcoming to “stand up” a positioning, navigation, and timing (PNT) user equipment joint program office (JPO) that would incorporate UE responsibilities (and budgets) now exercised by the GPS Wing (GPSW).

Figure 1: Synthetic Aperture GPS Signal Processing

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