LANG@UNB.CA (10/15/90)
On Wed, 3 Oct 90 11:04:07 EDT Mills@udel.edu writes: > Guys, > > I just noticed that sometime during the week of 22 August > the GPS dither was turned off; at least, this is apparent from > the USNO published corrections. During that week the pinball > noise on the block-II satellites ceased and the entire block-I/II > constellation wrenched a couple of hundred nanoseconds to some > new regime. The latest USNO notice mentioned a "Standard Postioning > Service," presumed different that tne "Global Positioning Service" > the taspayers paid for, but with the warning that the bubble > machine could be turned on at any time. This translation from > BeltwaySpeak brought to you as a professional courtesy. > > Dave According to the measurements made by the Bureau International des Poids et Mesures at the Paris Observatory, Selective Availability on the GPS Block II satellites was apparently switched off on or about 10 August. Although DoD denies it, this move appears to be associated with Operation Desert Shield. There really never has been a "Global Positioning Service." GPS = Global Positioning System. DoD announced the SPS and the PPS (Precise Positioning Service) at least as far back as 1984. See the magazine GPS World for all the latest dope on GPS and the evil sisters of Selective Availability and Anti-spoofing. ================================================================================ Richard B. Langley BITnet: LANG@UNB.CA or SE@UNB.CA Geodetic Research Laboratory Phone: (506) 453-5142 Dept. of Surveying Engineering Telex: 014-46202 University of New Brunswick FAX: (506) 453-4943 Fredericton, N.B., Canada E3B 5A3 ================================================================================