Dear Surveyor Site-Contacts,As you may have noticed from various news reports, an event known as "GPS Week 1024 rollover" is due to occur at midnight UTC August 21-22, 1999. At the Surveyor project, we've been aware of this event for about two years.
According to TrueTime, the provider of the GPS receiver cards that are used in our Surveyor measurement machines, immediately after midnight UTC August 21-22, there may be a 15-minute period during which the GPS card will report that it isn't receiving strong enough GPS signals to provide GPS quality time synchronization. As GPS cards routinely have short periods where they don't receive strong enough GPS signals to provide GPS quality time synchronization, the Surveyor measurement machines don't perform one-way-delay measurements during these periods. Thus, if TrueTime's prediction is accurate, the worse we will encounter is a 15-minute period during which we won't be collecting one-way-delay measurements.
For more information on the GPS Week 1024 Rollover, see http://www.navcen.uscg.mil/gps/geninfo/y2k/gpsweek.htm
Bill Cerveny Surveyor Project Advanced Network & Services, Inc.