Carrier phase differential GPS corrections network
First Claim
1. A method for determining corrections to carrier phase signals at an arbitrary location, the method comprising the steps of:
- determining corrections for carrier phase measurements from each of a plurality of GPS signals received at each of at least three GPS fiducial stations having known locations; and
determining a correction function that provides a carrier phase correction, for a GPS signal received at any selected location within a selected region, that is a selected linear combination of the carrier phase corrections determined for each of the at least three of the fiducial stations.
2 Assignments
0 Petitions
Accused Products
Abstract
Method and apparatus for providing GPS pseudorange correction information over a selected geographic region S with a diameter of up to 300 km with an associated inaccuracy no greater than 5 cm. N spaced apart GPS reference stations (N>4), whose location coordinates (un,vn,wn) are fixed and are known with high accuracy, are provided within or adjacent to the region R. Each reference station n(n=1, 2, . . . , N) receives GPS signals from at least four common-view GPS satellites, numbered m=1, 2, . . . , M (M≧4), computes its own GPS-determined location coordinates, compares these coordinates with its known location coordinates, determines the pseudorange corrections PRC(t;t0;m;n) for its GPS-determined location, and transmits these correction signals to a central station located within or adjacent to the region S. The central station retransmits the pseudorange correction signals throughout the region S. A mobile GPS station within or adjacent to the region S has stored within it the coordinates (u'"'"',v'"'"',w'"'"') of the GPS-determined last location of that mobile station and the spatial coordinates (un(k),vn(k),wn(k)) (k=1, 2 , . . . , K; K>3) of K GPS reference stations within S that are closest to the last-determined location of that mobile station. The mobile station then computes the differential GPS corrections for the GPS-determined present location of that mobile station. Alternatively, the reference stations can transmit to the central station unprocessed GPS signals for determination of the pseudorange correction signals at the central station. This approach can be modified if the region R is two-dimensional, where only two coordinates u and v are needed, or if the region R is one-dimensional, where only one coordinate u is needed. Suitable algorithms for selection of the coefficients ak'"'"' are discussed.
252 Citations
24 Claims
-
1. A method for determining corrections to carrier phase signals at an arbitrary location, the method comprising the steps of:
-
determining corrections for carrier phase measurements from each of a plurality of GPS signals received at each of at least three GPS fiducial stations having known locations; and determining a correction function that provides a carrier phase correction, for a GPS signal received at any selected location within a selected region, that is a selected linear combination of the carrier phase corrections determined for each of the at least three of the fiducial stations. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24)
-
Specification