Method and apparatus for generating and distributing satellite tracking information in a compact format

Abstract

A method and apparatus for creating and distributing satellite tracking data in a compact format to a remote receiver. At least a portion of the satellite tracking data is extracted from memory and is formatted into a compact format. The compact formatted data is transmitted to the remote receiver via a distribution network. Once this data is received at the remote receiver it is reformatted into a format prescribed by the remote receiver

What is claimed is: 
     
      
       1. A method of creating and distributing compact satellite orbit models comprising: 
       
         receiving satellite signals from at least one satellite and at least one receiving station; 
         extracting at least a portion of the satellite tracking data from said satellite signal, representing said data in a first format; 
         transmitting the formatted data to a remote receiver; and 
         at the remote receiver, representing said formatted data in a second format supported by the remote receiver. 
       
      
     
     
      
       2. The method of  claim 1  wherein said satellite tracking data comprises at least one of a satellite orbit model or a satellite clock model. 
      
     
     
       3. The method of  claim 1  wherein said satellite tracking data comprises at least one of: data representative of a satellite orbit model, orbit model, data representative of a satellite clock model. 
     
     
       4. The method of  claim 1  wherein said second format is a format that is prescribed by said remote receiver. 
     
     
      
       5. The method of  claim 1  wherein said second format comprises parameters defined in ICD-GPS-200. 
      
     
     
       6. The method of  claim 1  wherein said first format comprises a first set of terms that define a first form of orbit model, and said second format comprises a second set of terms that define a second form of orbit model, and said second set of terms is larger than said first set of terms. 
     
     
       7. The method of  claim 1  wherein said first format comprises a first set of terms that define a first form of orbit model, and said second format comprises a second set of terms that define a second form of orbit model, where said second set of terms contains said first set of terms. 
     
     
       8. The method of  claim 1  wherein said first format comprises a first set of terms that define a first form of orbit model and said second format comprises a second set of terms that define a second form of orbit model, and at least one term of said first set is defined as a number with lower resolution than the corresponding term in second set. 
     
     
       9. The method of  claim 1  where said data in a first format requires fewer bits to encode it than said data in a second format. 
     
     
       10. The method of  claim 1  wherein said remote receiver is a GPS receiver. 
     
     
       11. The method of  claim 1  wherein said remote receiver is a satellite positioning system receiver. 
     
     
       12. The method of  claim 1  wherein said second format is a standard format for providing satellite models to a global positioning system receiver. 
     
     
       13. The method of  claim 1  wherein said transmitting is performed using a wireless communications link. 
     
     
       14. The method of  claim 13  wherein said transmitting is done without requiring from said remote receiver data representative of said remote receiver's position. 
     
     
       15. The method of  claim 1  where an accuracy of the data in said first format is increased by decreasing a time interval represented by said formatted data. 
     
     
       16. A method of creating and distributing a compact orbit model, the method comprising:
 receiving satellite signals measurement data from at least one a receiving station, the measurement data being based on satellite signals received by the receiving station; 
 extracting at least a portion of the satellite tracking data from the satellite signal, where saidmeasurement data, wherein the portion of the satellite tracking data comprises a first number of orbit terms that define a first orbit model, the orbit terms comprising harmonic and non-harmonic parameters; 
 formatting said the portion of the satellite tracking data to form formatted data having a second number of orbit terms that define a second orbit model, where said wherein the first number of orbit terms is greater than said the second number of orbit terms, the second number of orbit terms excluding the harmonic parameters; 
 transmitting the formatted data to a remote receiver; and 
 at the remote receiver, expanding, by the remote receiver, the formatted data to have the first number of orbit terms, and using the expanded data to determine a location of the remote receiver. 
 
     
     
       17. The method of  claim 16 , wherein said the satellite tracking data comprises at least one of a satellite orbit model or a data and satellite clock model data. 
     
     
       18. The method of  claim 16  wherein said satellite tracking data comprises at least one of: data representative of a satellite orbit model, orbit model, data representative of a satellite clock model. 
     
     
       19. The method of  claim 16 , wherein said the second orbit model is a compact orbit model. 
     
     
       20. The method of  claim 16  wherein said expanding step results in a data format that is prescribed by said remote receiver. 
     
     
       21. The method of  claim 20  wherein the data format having the first number of terms comprises parameters defined in ICD-GPS-200. 
     
     
       22. The method of  claim 16 where said, wherein the terms in said second orbit model require is encoded with fewer bits to encode it than said a number of bits required to encode the terms in a the first orbit model. 
     
     
       23. The method of  claim 16 , wherein said the remote receiver is a GPS global positioning system (GPS) receiver. 
     
     
       24. The method of  claim 16 , wherein said the remote receiver is a satellite positioning system receiver. 
     
     
       25. The method of  claim 16  where an accuracy of the data in said second orbit model is increased by decreasing a time interval represented by said formatted data defining said second orbit model. 
     
     
       26. A method of creating a compact orbit model, the method comprising:
 receiving, by a global positioning system (GPS) receiver, satellite tracking information from one or more satellites; 
 providingtransmitting, to a server, a satellite orbit model having a first set of termssatellite ephemeris parameters determined from the satellite tracking information, the first set of ephemeris parameters comprising harmonic parameters and non-harmonic parameters; 
 adjusting, by the server, the first set of terms satellite ephemeris parameters to produce a the compact orbit model having a second set of terms where satellite ephemeris parameters, wherein a number of terms parameters in the first set of terms of satellite ephemeris parameters is greater than a number of terms parameters in said the second set of satellite ephemeries parametersof terms, the second set of satellite ephemeris parameters excluding the harmonic parameters; and 
 transmitting the compact orbit model to a remote receiver configured to determine a location of the remote receiver, wherein the remote receiver is configured to expand the compact orbit model, and wherein the location is based on the expanded compact orbit model. 
 
     
     
       27. The method of  claim 26 , wherein said the adjusting step further comprises:
 zeroing a plurality of terms the harmonic parameters in said the first set of terms satellite ephemeris parameters. 
 
     
     
       28. The method of  claim 27 , wherein said the adjusting step further comprises:
 adjusting a plurality of non-zero terms the non-harmonic parameters in the second set of terms satellite ephemeris parameters in response to the effects of zeroing terms of the harmonic parameters in the first set of terms satellite ephemeris parameters. 
 
     
     
       29. Apparatus An apparatus for creating and distributing compact satellite orbit models, the apparatus comprising:
 at least onea satellite signal receiver for receiving satellite signals from at least onea satellite; 
 means for collecting measurement data from the satellite signals received by the satellite signal receiver and extracting at least a portion of the satellite tracking data from said the measurement data to represent satellite signal, representing said the portion of the satellite tracking data in a first format that includes a first set of terms that define a first form of an orbit model, the first set of terms comprising harmonic and non-harmonic parameters; 
 means for reformatting the first form of the orbit model to generate a second format including a second set of terms that define a second form of the orbit model, the second form excluding the harmonic parameters; 
 a transmitter for transmitting the formatted portion of the satellite tracking data in the second format to a remote receiver; and 
 atwherein the remote receiver, representing said formattedrepresents the portion of the satellite tracking data in a secondthe second format back into the first format supported by the remote receiver, and wherein the remote receiver is configured to use the first format to determine a location of the remote receiver. 
 
     
     
       30. The apparatus of  claim 29  wherein said second format is a format that is prescribed by said remote receiver. 
     
     
       31. The apparatus of  claim 29  wherein said second format comprises parameters defined in ICD-GPS-200. 
     
     
       32. The apparatus of  claim 29  wherein said first format comprises a first set of terms that define a first form of orbit model, and said second format comprises a second set of terms that define a second form of orbit model, and said second set of terms is larger than said first set of terms. 
     
     
       33. The apparatus of  claim 29 , wherein said the transmitter is a wireless communications transmitter. 
     
     
       34. A method of creating and distributing compact satellite orbit models, the method comprising:
 receiving, from at least one receiving station, measuring data from satellite signals received by the at least one receiving station;   extracting a portion of satellite tracking data from the measurement data;   representing the extracted portion of satellite tracking data as a compact satellite orbit model having a first format, wherein the compact satellite orbit model is a subset of satellite ephemeris parameters, wherein the satellite ephemeris parameters includes harmonic and non-harmonic parameters, and wherein the representing the extracted portion of satellite tracking data as the compact satellite orbit model comprises excluding the harmonic parameters;   transmitting the compact satellite orbit model having the first format to a remote receiver;   representing, by the remote receiver, the compact satellite orbit model having the first format in a second satellite orbit model having a second format supported by the remote receiver, wherein the second satellite orbit model includes the satellite ephemeris parameters; and   using the second satellite orbit model to determine a location of the remote receiver.   
     
     
       35. The method of claim 34, wherein the satellite tracking data comprises satellite clock data. 
     
     
       36. The method of claim 34, wherein the extracting includes extracting the portion of the satellite tracking data in accordance with a desired time interval. 
     
     
       37. The method of claim 36, further comprising:
 initializing a value of a parameter from the subset of satellite ephemeris parameters based on a previous value of a parameter of a previous time interval from the subset of satellite ephemeris parameters associated with the previous time interval; and   adjusting the initialized value of the parameter from the subset of satellite ephemeris parameters for an entire duration of the desired time interval.   
     
     
       38. The method of claim 37, wherein the adjusting includes adjusting the initialized value of one of the non-harmonic parameters to have an equivalent value to a representation of the one of the non-harmonic parameters and one of the harmonic parameters. 
     
     
       39. The method of claim 38, wherein the one of the harmonic parameters is excluded from the subset of satellite ephemeris parameters. 
     
     
       40. The method of claim 34, wherein the remote receiver is a global positioning system (GPS) receiver. 
     
     
       41. The method of claim 34, wherein the remote receiver is a satellite positioning system receiver. 
     
     
       42. The method of claim 34, wherein the second format is a format for providing satellite models to a global positioning system (GPS) receiver. 
     
     
       43. The method of claim 34, wherein the transmitting is performed using a wireless communications link. 
     
     
       44. The method of claim 43, wherein the transmitting is carried out in a manner not requiring, from the remote receiver, data representative of the location of the remote receiver. 
     
     
       45. The method of claim 34, wherein the representing the compact satellite orbit model as the second satellite orbit model comprises:
 replacing the excluded harmonic parameters with a value of zero.   
     
     
       46. The method of claim 34, wherein the representing the compact satellite orbit model as the second satellite orbit model comprises:
 replacing the excluded harmonic parameters with a predetermined value determined from global positioning system (GPS) almanac data.   
     
     
       47. An apparatus for creating and distributing compact satellite orbit models, the apparatus comprising:
 a satellite signal receiver for receiving satellite signals from a satellite;   means for collecting measurement data from the satellite signals received by the satellite signal receiver and extracting a portion of satellite tracking data from the measurement data to represent the portion of the satellite tracking data as a compact satellite orbit model having a first format, wherein the compact satellite orbit model is a subset of satellite ephemeris paramaters including harmonic and non-harmonic parameters, and wherein the compact satellite orbit model excludes the harmonic paramerers;   a transmitter for transmitting the compact satellite orbit model to a remote receiver; and   wherein the remote receiver represents the compact satellite orbit model in a second satellite orbit model having a second format supported by the remote receiver and determines a location of the remote receiver using the second satellite orbit model, wherein the second satellite orbit model includes the satellite ephemeris parameters.   
     
     
       48. The apparatus of claim 47, wherein the remote receiver replaces the excluded harmonic parameters with a value of zero to represent the compact satellite orbit model as the second satellite orbit model. 
     
     
       49. The apparatus of claim 47, wherein the remote receiver replaces the excluded harmonic parameters with a predetermined value determined from global positioning system (GPS) almanac data to represent the compact satellite orbit model as the second satellite orbit model.