GIAC GPS Interagency Advisory Council

The PRN 19 Anomaly tests scheduled for August 15-18 have been rescheduled to September 10-12.  I apologize for the short notice, and we are still working to improve the coordination process.  I'm accepting comments, complaints and criticisms.  I will send out the test plan and detailed schedule when they become available.
Frank Lorge, GPS Civil Test Director, 609-485-4588, frank.lorge@faa.gov

The new tentative schedule for PRN 19 Anomaly tests is from August 15-18. We will use the same coordination process for stopping the tests quickly if users experience severe problems. The point of contact will be the US Coast Guard 24-hour information watch. The phone number for the watch is (703) 313-5900 and email: nisws@navcen.uscg.mil. 

The planned anomaly test on PRN 19, tentatively scheduled for June 18, 2001, has been delayed indefinitely pending further review by the Air Force. 

There are tentative plans to perform a Digital Distortion Anomaly test on GPS satellite PRN19.  The tentative plan is that the test will begin on June 18, 2001, and will last for 5.5 days (132 hours).  The health bit for PRN19 will be set to “UNHEALTHY” for the duration of this test.  This test is not expected to be noticed with standard GPS receivers, since such equipment should not process data from unhealthy satellites.

One purpose of this test is to attempt to replicate a signal distortion observed in 1993 on PRN19.  When the distortion first occurred, it was corrected by switching to an alternative hardware path within the satellite.  If the distorted signal is successfully generated, it will be used to assess the performance of specialized GPS test equipment known as signal quality monitors.  These monitors are important components in aviation augmentation systems.

We will update this web site as test plans are finalized.  It is likely that information will also be made available through the U.S. Coast Guard Navigation Center.

for information write:
GPS INTERAGENCY ADVISORY COUNCIL
FEDERAL GEODETIC CONTROL SUBCOMMITTEE
NOAA, National Geodetic Survey, N/NGS
1315 East-West Highway, Room 8657
Silver Spring, Maryland 20910-3282