Satellite position fixing
First Claim
1. A system for estimating a position of a satellite of a mobile communication system at a particular instant of time wherein said satellite is operable to cooperate with an earth station to measure and record the position of a terminal on the surface of the earth by reference to an estimated, instant position of said satellite, said earth station being operable to estimate said instant position of said satellite with a first accuracy, wherein said system is operable to incorporate the measured position of said terminal to make a re-estimation of said instant position of said satellite with a second accuracy, said second accuracy being greater than said first accuracy.
1 Assignment
0 Petitions
Accused Products
Abstract
In a satellite position fixing system, where an earth station 38 communicates with a satellite 10 which, in turn, communicates with selectable ones out of a plurality of user terminals 44 whose position, on the surface of the earth 14, is measured, the accuracy of measurement of the position of the satellite 10 is improved by using all of the user terminals 44 as further triangulation points, the improved position being incorporated in further user terminal 44 position determinations, and so on to create a cumulative improvement. Weighting is applied so that user terminals 44 with large errors in triangulation are given small significance and those with small errors are given great significance.
12 Citations
14 Claims
- 1. A system for estimating a position of a satellite of a mobile communication system at a particular instant of time wherein said satellite is operable to cooperate with an earth station to measure and record the position of a terminal on the surface of the earth by reference to an estimated, instant position of said satellite, said earth station being operable to estimate said instant position of said satellite with a first accuracy, wherein said system is operable to incorporate the measured position of said terminal to make a re-estimation of said instant position of said satellite with a second accuracy, said second accuracy being greater than said first accuracy.
- 8. A method for estimating a position of a satellite of a mobile communication system at a particular instant of time for use in a system wherein said satellite is operable to cooperate with an earth station to measure and record the position of a terminal on the surface of the earth by reference to an estimated, instant position of said satellite, said earth station being operative to estimated said instant position of said satellite with a first accuracy, said method including the step of incorporating the measured position of said terminal in a re-estimation of said instant position of said satellite with a second accuracy, said second accuracy being greater than said first accuracy.
Specification