ION Technical Content
GPS Signal Policy
| Abstract: | GPS provides two types of positioning/navigation services - the standard Positioning Service (SPS) and the Precise Positioning Service (PPS). The SPS signal is normally thought to be the CPS signals and data sent in the clear from the satellite. This is basically true. but there are some qualifications to this. From a policy standpoint. the SPS signal consists of the Ll frequency, the coarse/acquisition (C/A) code. and the unencrypted portions of the navigation message. While the LZ frequency and the precise (P) code can be tracked and processed by appropriately designed SPS receivers, these signals are not considered part of the SPS. (The U.S. Government does not assure the availability of the P code for civil navigation.) The PPS signal basically comprises the clear SPS plus the encrypted signals and data transmitted by the CPS satellite. Specifically, the PPS signal consists of the Ll and L2 frequencies, the Y code. which is the encrypted P code, and the selective availability corrections. Selective availability (SA) is the method used to control access to the PPS. |
| Published in: |
Proceedings of the 4th International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GPS 1991) September 11 - 13, 1991 Albuquerque, NM |
| Pages: | 33 - 38 |
| Cite this article: | McNeff, Jules G., "GPS Signal Policy," Proceedings of the 4th International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GPS 1991), Albuquerque, NM, September 1991, pp. 33-38. |
| Full Paper: |
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