Method and apparatus for obtaining satellite trajectory data at a satellite positioning system receiver

Abstract

Method and apparatus for locating position of a mobile receiver is described. In one embodiment, satellite measurements are obtained at the mobile receiver for a plurality of satellites in a satellite positioning system constellation. Satellite trajectory data is obtained at the mobile receiver from a server. Ephemeris data is obtained at the mobile receiver from at least one satellite of the plurality of satellites. Position is computed for the mobile receiver using the satellite measurements, the satellite trajectory data, and the ephemeris data.

1 . A method of locating position of a mobile receiver, comprising: 
 obtaining satellite measurements at said mobile receiver for a plurality of satellites in a satellite positioning system constellation;    obtaining satellite trajectory data at said mobile receiver from a server;    obtaining ephemeris data at said mobile receiver from at least one satellite of said plurality of satellites; and    computing position of said mobile receiver using said satellite measurements, said satellite trajectory data, and said ephemeris data.    
     
     
         2 . The method of  claim 1 , wherein said satellite trajectory data is obtained from said server at a first time, and wherein the method further comprises: 
 detecting connectivity between said mobile receiver and said server at a second time;    wherein said ephemeris data is obtained from said at least one satellite in response to absence of said connectivity at said second time.    
     
     
         3 . The method of  claim 1 , wherein said satellite trajectory data is obtained from said server at a first time and said ephemeris data is obtained from said at least one satellite at a second time, and wherein the method further comprises: 
 determining whether a combination of said satellite trajectory data and said ephemeris data includes data for each of said plurality of satellites; and    obtaining additional satellite trajectory data at said mobile receiver from said server in response to said combination ephemeris data not including data for each of said plurality of satellites.    
     
     
         4 . The method of  claim 1 , wherein said satellite trajectory data is obtained from said server at a first time and said ephemeris data is obtained from said at least one satellite at a second time, and wherein the method further comprises: 
 processing a combination of said satellite trajectory data and said ephemeris data to identify missing data for said plurality of satellites; and    obtaining said missing data at said mobile receiver from said server.    
     
     
         5 . The method of  claim 1 , wherein said satellite trajectory data comprises ephemeris.  
     
     
         6 . The method of  claim 1 , wherein said satellite trajectory data is associated with a set of satellites in said satellite positioning system constellation exclusive of said at least one satellite.  
     
     
         7 . The method of  claim 6 , wherein said satellite trajectory data is obtained at a first time and said ephemeris data is obtained at a second time, and wherein said at least one satellite is not in view of said mobile receiver at said first time.  
     
     
         8 . The method of  claim 1 , wherein said step of obtaining said ephemeris data comprises: 
 detecting at least one satellite signal broadcast by said at least one satellite; and    decoding said at least one satellite signal to obtain said ephemeris data.    
     
     
         9 . A mobile receiver, comprising: 
 a wireless transceiver for obtaining satellite trajectory data from a server;    a satellite signal receiver for obtaining satellite measurements for a plurality of satellites in a satellite positioning system constellation and obtaining ephemeris data from at least one satellite of said plurality of satellites; and    a processor for computing position of said mobile receiver using said satellite measurements, said satellite trajectory data, and said ephemeris data.    
     
     
         10 . The mobile receiver of  claim 9 , further comprising: 
 means for detecting connectivity between said mobile receiver and said server;    wherein said satellite signal receiver is configured to obtain said ephemeris data from said at least one satellite in response to absence of said connectivity at said second time.    
     
     
         11 . The mobile receiver of  claim 9 , further comprising: 
 means for determining whether a combination of said satellite trajectory data and said ephemeris data includes data for each of said plurality of satellites;    wherein said wireless transceiver is configured to obtain additional satellite trajectory data from said server in response to said combination ephemeris data not including data for each of said plurality of satellites.    
     
     
         12 . The mobile receiver of  claim 9 , wherein said processor is configured to process a combination of said satellite trajectory data and said ephemeris data to identify missing data for said plurality of satellites, and wherein said wireless transceiver is configured to obtain said missing data from said server.  
     
     
         13 . The mobile receiver of  claim 9 , wherein said satellite trajectory data comprises ephemeris.  
     
     
         14 . The mobile receiver of  claim 9 , wherein said satellite trajectory data is associated with a set of satellites in said satellite positioning system constellation exclusive of said at least one satellite.  
     
     
         15 . The mobile receiver of  claim 9 , wherein said satellite signal receiver is configured to: 
 detect at least one satellite signal broadcast by said at least one satellite; and    decode said at least one satellite signal to obtain said ephemeris data.    
     
     
         16 . Apparatus for locating position of a mobile receiver, comprising: means for obtaining satellite measurements at said mobile receiver for a plurality of satellites in a satellite positioning system constellation; 
 means for obtaining satellite trajectory data at said mobile receiver from a server;    means for obtaining ephemeris data at said mobile receiver from at least one satellite of said plurality of satellites; and    means for computing position of said mobile receiver using said satellite measurements, said satellite trajectory data, and said ephemeris data.    
     
     
         17 . The apparatus of  claim 16 , wherein said satellite trajectory data is obtained from said server at a first time, and wherein the apparatus further comprises: 
 means for detecting connectivity between said mobile receiver and said server at a second time;    wherein said ephemeris data is obtained from said at least one satellite in response to absence of said connectivity at said second time.    
     
     
         18 . The apparatus of  claim 16 , wherein said satellite trajectory data is obtained from said server at a first time and said ephemeris data is obtained from said at least one satellite at a second time, and wherein the apparatus further comprises: 
 means for determining whether a combination of said satellite trajectory data and said ephemeris data includes data for each of said plurality of satellites; and    means for obtaining additional satellite trajectory data at said mobile receiver from said server in response to said combination ephemeris data not including data for each of said plurality of satellites.    
     
     
         19 . The apparatus of  claim 16 , wherein said satellite trajectory data is obtained from said server at a first time and said ephemeris data is obtained from said at least one satellite at a second time, and wherein the apparatus further comprises: 
 means for processing a combination of said satellite trajectory data and said ephemeris data to identify missing data for said plurality of satellites; and    means for obtaining said missing data at said mobile receiver from said server.    
     
     
         20 . The apparatus of  claim 16 , wherein said satellite trajectory data comprises ephemeris.  
     
     
         21 . The apparatus of  claim 16 , wherein said satellite trajectory data is associated with a set of satellites in said satellite positioning system constellation exclusive of said at least one satellite.  
     
     
         22 . The apparatus of  claim 21 , wherein said satellite trajectory data is obtained at a first time and said ephemeris data is obtained at a second time, and wherein said at least one satellite is not in view of said mobile receiver at said first time.  
     
     
         23 . The apparatus of  claim 16 , wherein said means for obtaining said ephemeris data comprises: 
 means for detecting at least one satellite signal broadcast by said at least one satellite; and    means for decoding said at least one satellite signal to obtain said ephemeris data.