Method and apparatus for satellite-based relative positioning of moving platforms

Abstract

The present invention is directed to the determination of a relative position between moving platforms, using satellite-based navigation techniques and equipment installed on said platforms. It combines the concepts of observation-space and navigation-space differential systems, and operates a DGNSS base station in a time-varying mode, in order to rely on the built-in differential positioning and navigation capabilities of particular GNSS receivers while minimizing datalink loading and computational load in auxiliary processors. The invention achieves accurate relative positioning and navigation with respect to a moving base station, using DGNSS equipment that assumes it is stationary when operated in a reference station mode.

1 . A method for providing information for calculating a baseline between a moving base station and a moving rover station, the method comprising: 
 collecting navigation-domain information indicating current position of the base station at navigation-domain times; and    collecting observation-domain information indicating current position of the base station at observation-domain times    wherein the observation-domain times are less frequent than the navigation domain times.    
     
     
         2 . The method of  claim 1  including after collecting information, transmitting information derived from the collected information to the rover station.  
     
     
         3 . The method of  claim 1  wherein the times are at fixed intervals.  
     
     
         4 . The method of  claim 1  wherein the collecting of navigation-domain information includes setting a positioning receiver to operating in rover mode.  
     
     
         5 . The method of  claim 1  wherein the collecting of navigation-domain information includes setting a positioning receiver to provide navigation-domain information.  
     
     
         6 . The method of  claim 1  wherein the collecting of observation-domain information includes setting a positioning receiver to operating in reference mode.  
     
     
         7 . The method of  claim 1  wherein the collecting of observation-domain information includes setting a positioning receiver to provide observation-domain information.  
     
     
         8 . The method of  claim 1  wherein the collecting of navigation-domain information includes setting a positioning receiver to provide navigation-domain information and the collecting of observation-domain information includes setting a positioning receiver to operating in reference mode.  
     
     
         9 . The method of  claim 8  wherein the positioning receiver is a GPS-based receiver.  
     
     
         10 . A method for calculating relative position between a moving base station and a moving rover station, the method comprising: 
 receiving navigation-domain information indicating current position of the base station at navigation-domain times;    receiving observation-domain information indicating current position of the base station at observation-domain times;    when observation-domain information is received, calculating a relative position of based on the received observation-domain information; and    when navigation-domain information is received, calculating a relative position of based on a previously calculated relative position and the received navigation-domain information    wherein the observation-domain times are less frequent than the navigation domain times.    
     
     
         11 . The method of  claim 10  wherein the navigation-domain information and observation-domain information are received at the rover station from the base station.  
     
     
         12 . The method of  claim 10  wherein the times are at fixed intervals.  
     
     
         13 . The method of  claim 10  wherein the navigation-domain information is collected by setting a positioning receiver to operating in rover mode.  
     
     
         14 . The method of  claim 10  wherein the navigation-domain information is collected by setting a positioning receiver to provide navigation-domain information.  
     
     
         15 . The method of  claim 10  wherein the observation-domain information is collected by setting a positioning receiver to operating in reference mode.  
     
     
         16 . The method of  claim 10  wherein the observation-domain information is collected by setting a positioning receiver to provide observation-domain information.  
     
     
         17 . The method of  claim 10  wherein the navigation-domain information is collected by setting a positioning receiver to provide navigation-domain information and the observation-domain information is collected by setting a positioning receiver to operating in reference mode.  
     
     
         18 . The method of  claim 17  wherein the positioning receiver is a GPS-based receiver.