What is the Standard Positioning Service?
GPS provides two levels of service — a Standard Positioning Service (SPS) for general public use and an encoded Precise Positioning Service (PPS) primarily intended for use by the Department of Defense. SPS signal accuracy is intentionally degraded to protect U.S. national security interests. This process, called Selective Availability (SA), controls the availability of the system’s full capabilities. The SPS accuracy specifications, given below, include the effects of SA. SPS provides accuracy’s of (for position, the accuracy with respect to geographic, or geodetic coordinates of the Earth) within: 100 meters (2 drms) horizontal 156 meters (2 Sigma) vertical 300 meters (99.99% prob.) horizontal 340 nanoseconds time (95% prob.) SPS Coverage is continuous and worldwide, with a position dilution of precision (PDOP) of 6 or less.
GPS provides two levels of service: A Standard Positioning Service (SPS) for general civil use and an encoded Precise Positioning Service (PPS) primarily intended for use by the Department of Defense and U.S. allies. The SPS is the standard specified level of positioning and timing accuracy that is available, without restrictions, to any user on a continuous worldwide basis. SPS provides accuracies (for position, the accuracy with respect to geographic or geodetic coordinates of the Earth) within: 100 meters (2 drms) horizontal, 156 meters (2 Sigma) vertical, 300 meters (99.99% prob.) horizontal, 340 nanoseconds time (95% prob.). SPS Coverage is continuous and worldwide, with a position dilution of precision (PDOP) of 6 or less. These accuracy´s reflect the last signal specification in the Federal Radionavigation Plan, the signal specification is in the process of being revised to reflect the accuracy obtained with Selective Availability (SA) turned off.
GPS provides two levels of service — a Standard Positioning Service (SPS) for general public use and an encoded Precise Positioning Service (PPS) primarily intended for use by the Department of Defense. SPS signal accuracy is intentionally degraded to protect U.S. national security interests. This process, called Selective Availability (SA), controls the availability of the system’s full capabilities. The SPS accuracy specifications, given below, include the effects of SA. SPS provides accuracies of (for position, the accuracy with respect to geographic, or geodetic coordinates of the Earth) within: 100 meters (2 drms) horizontal 156 meters (2 Sigma) vertical 300 meters (99.99% prob.) horizontal 340 nanoseconds time (95% prob.) SPS Coverage is continuous and worldwide, with a position dilution of precision (PDOP) of 6 or less.
