Updating atmospheric delay models with a geographic region

Abstract

A central location system provides an end-to-end high-accuracy positioning solution that provides navigation, geo-tagging, and general positioning data to receivers. The central location system does this by providing a cloud correction service and a robust positioning engine. For example, the central location system may provide single-frequency receivers with corrections for atmospheric delays and multipath throughout different geographic regions. The central location system computes corrections by leveraging location data from dual-frequency receivers. The central location system may also increase ionospheric delay coverage of portions of a geographic region. With increased ionospheric delay coverage, receivers can compute better location estimates. The central location system may also compute refined location estimates of single-frequency receivers and/or dual-frequency receivers for receivers with limited access to signals transmitted from satellites. The central location system may do this by estimating a receiver's location with respect to the location estimates of other receivers.

1 . (canceled) 
     
     
         2 . A method, comprising:
 accessing, at a processing system, an ionospheric delay model for a geographic region;   detecting a portion of the geographic region for which the ionospheric delay model is insufficient;   identifying a dual-frequency receiver located within a threshold distance of the detected portion of the geographic region;   instructing the identified dual-frequency receiver to provide a measurement of the ionospheric delay within the detected portion of the geographic region; and   updating the ionospheric delay model using the provided measurement of the ionospheric delay.   
     
     
         3 . The method of  claim 2 , wherein the dual-frequency receiver is integrated into a mobile user device. 
     
     
         4 . The method of  claim 2 , further comprising: updating the ionospheric delay model in response to detecting a threshold change in atmospheric conditions of the geographic region. 
     
     
         5 . The method of  claim 2 , wherein detecting that the ionospheric delay model is insufficient for the portion of the geographic region comprises at least one of:
 determining that a measure of ionospheric delay has not been received from a location within a threshold distance of the geographic region or a location within the geographic region for a threshold amount of time,   determining that the measure of ionospheric delay has not been received by at least a threshold number of receivers within the threshold distance of the geographic region, or   determining that the ionospheric delay model for the geographic region has not been updated within a threshold period of time.   
     
     
         6 . The method of  claim 2 , further comprising: providing a location estimate to a user based on the updated ionospheric delay model. 
     
     
         7 . The method of  claim 2 , wherein the dual-frequency receiver is located within the detected portion of the geographic region. 
     
     
         8 . The method of  claim 7 , wherein instructing the dual-frequency receiver to measure the ionospheric delay within the detected portion of the geographic region further includes activating the dual-frequency receiver. 
     
     
         9 . The method of  claim 2 , wherein instructing the dual-frequency receiver to measure the ionospheric delay within the detected portion of the geographic region further includes activating the dual-frequency receiver to relocate to the detected portion of the geographic region. 
     
     
         10 . The method of  claim 2 , wherein instructing the dual-frequency receiver to measure the ionospheric delay within the detected portion of the geographic region further includes identifying a user corresponding to a dual-frequency receiver located outside of the detected portion of the geographic region and incentivizing the user to relocate to the detected portion of the geographic region. 
     
     
         11 . The method of  claim 2 , further comprising:
 generating, on a user device of a user, a user interface, the user interface including a map of the geographic region and the measure of ionospheric delay coverage for one or more portions of the map; and   identifying, within the map, portions of the geographic region corresponding to a below-threshold level of ionospheric delay coverage.