Systems, methods and devices for satellite navigation reconciliation

Abstract

A three-dimensional map of an environment with buildings is used to computationally predict locations and times of global navigation satellite system (GNSS) transmission quality. A global navigation satellite system (GNSS) receiver can reconcile received satellite transmissions with these predicted satellite transmissions. By comparing actual transmission quality with predicted transmission quality, a system can determine unmodeled obstructions, temporary obstructions, jamming, spoofing or other origins of interference with predicted transmission quality of a satellite in a GNSS.

1 . A method for using global navigation satellite system (GNSS) comprising:
 receiving a measured transmission quality of a signal transmission of a satellite in the GNSS at a spacetime position;   predicting a predicted transmission quality from the satellite to the spacetime position based on a three-dimensional spatial map of an environment including one or more buildings and satellite ephemeris data; and   determining an anomaly exists based at least in part on the measured transmission quality and the predicted transmission quality.   
     
     
         2 . A method for using global navigation satellite system (GNSS) comprising:
 receiving a set of measured transmission qualities of signal transmissions of a set of satellites in the GNSS at a spacetime position;   predicting a set of predicted transmission qualities from the set of satellites to the spacetime position based on a three-dimensional spatial map of an environment and satellite ephemeris data; and   determining an anomaly exists based at least in part on the set of measured transmission qualities and the set of predicted transmission qualities.   
     
     
         3 . The method of  claim 2 , wherein determining an anomaly exists based at least in part on the set of measured transmission qualities and the set of predicted transmission qualities comprises comparing one or more measured transmission qualities from a specified satellite in the set of satellites to one or more predicted transmission qualities from the specified satellite. 
     
     
         4 . The method of  claim 2 , wherein the three-dimensional spatial map comprises one or more man-made structures. 
     
     
         5 . The method of  claim 2 , wherein determining the anomaly exists further comprises determining that a locus of the set of measured transmission qualities converges to identify an unmodeled obstruction on the three-dimensional spatial map. 
     
     
         6 . The method of  claim 5 , further comprising adding the unmodeled obstruction to the three-dimensional spatial map. 
     
     
         7 . The method of  claim 6 , further comprising transmitting at least the unmodeled obstruction to a network service that provides the three-dimensional spatial map. 
     
     
         8 . The method of  claim 5 , further comprising:
 updating the three-dimensional spatial map to include the unmodeled obstruction;   providing the updated three-dimensional spatial map via a network service.   
     
     
         9 . The method of  claim 2 , further comprising identifying the spacetime position as a candidate for secondary navigation. 
     
     
         10 . The method of  claim 9 , wherein the secondary navigation is assisted global positioning system. 
     
     
         11 . The method of  claim 2 , further comprising receiving the three-dimensional spatial map of the environment from a network service. 
     
     
         12 . The method of  claim 2 , wherein receiving a set of measured transmission qualities of signal transmissions of a set of satellites in the GNSS at a spacetime position further comprises receiving, from a plurality of devices, the set of measured transmission qualities. 
     
     
         13 . The method of  claim 2 , further comprising providing an application program interface (API) configured to provide the three-dimensional spatial map of the environment. 
     
     
         14 . The method of  claim 2 , wherein receiving a set of measured transmission qualities further comprises determining that a signal transmission from a satellite in the set of satellites is obstructed. 
     
     
         15 . The method of  claim 14 , further comprising predicting a spacetime location when the signal transmission will be greater than or equal to a transmission quality threshold. 
     
     
         16 . The method of  claim 15 , wherein predicting the spacetime location when the signal transmission will be greater than or equal to the transmission quality threshold further comprises predicting a duration of time that the signal transmission will be greater than or equal to the transmission quality threshold after the spacetime location. 
     
     
         17 . The method of  claim 2 , wherein receiving a set of measured transmission qualities further comprises determining that a signal transmission from a satellite in the set of satellites is greater than or equal to a transmission quality threshold. 
     
     
         18 . The method of  claim 17 , further comprising predicting a spacetime location when the signal transmission will be less than or equal to the transmission quality threshold. 
     
     
         19 . The method of  claim 18 , wherein predicting the spacetime location when the signal transmission will be less than or equal to the transmission quality threshold further comprises predicting a duration of time that the signal transmission will be less than or equal to the transmission quality threshold after the spacetime location. 
     
     
         20 . The method of  claim 2 , further comprising using the set of satellites in the GNSS to determine a geographic position. 
     
     
         21 . A method for using global navigation satellite system (GNSS) comprising:
 receiving a spacetime location; and   applying the spacetime location to a time dependent coverage map derived at least in part from an environment map that includes one or more buildings to estimate transmission quality of a satellite from the GNSS at the spacetime location.   
     
     
         22 . The method of  claim 21 , further comprising one or more instructions that, when executed by the one or more processors of the computer system, cause the computer system to at least:
 applying the spacetime location to a set of time dependent coverage maps derived at least in part from the environment map that includes the one or more buildings to estimate a set of transmission qualities of a set of satellites from the GNSS at the spacetime location; and   predicting coverage of the GNSS based at least in part on the set of transmission qualities.   
     
     
         23 . The method of  claim 21 , further comprising constructing the time dependent coverage map based at least in part on GNSS satellite ephemeris data and a three-dimensional spatial map of an environment that includes the buildings. 
     
     
         24 . The method of  claim 23 , wherein constructing further comprises simulating transmissions from a set of satellites in the GNSS within the three-dimensional spatial map of the environment over a time period. 
     
     
         25 . The method of  claim 21 , further comprising retrieving the time dependent coverage map from a network service. 
     
     
         26 . The method of  claim 21 , wherein applying the spacetime location to the time dependent coverage map further comprises:
 transmitting the spacetime location to a service over a network; and   receiving data representing predicted transmission qualities of GNSS satellites at the spacetime location.   
     
     
         27 . The method of  claim 21 , wherein applying the spacetime location to the time dependent coverage map further comprises:
 receiving data representing predicted transmission qualities of GNSS satellites at a future predicted spacetime location.   
     
     
         28 . The method of  claim 21 , wherein applying the spacetime location to the time dependent coverage map further comprises:
 determining a position within a three-dimensional spatial map of an environment and a time;   determining a satellite position at the time based at least in part on satellite ephemeris data;   simulating a signal transmission from the satellite to the position at the time within the three-dimensional spatial map of the environment; and   determining a signal transmission quality of the signal transmission at the position and the time.   
     
     
         29 . A system for navigation, comprising:
 storage configured to store a three-dimensional spatial map of an environment including one or more buildings and satellite ephemeris data;   a processor configured to:
 determine a first route associated with a first set of times within the three-dimensional spatial map; 
 determine a first set of positions of a first set of satellites associated with the first set of times based at least in part on satellite ephemeris data; 
 simulate transmission of first satellite navigation signals from the first set of satellites to the first route at the associated first set of times; 
 determine a first set of transmission qualities associated with the first set of satellites to the first route associated with the first set of times. 
   
     
     
         30 . The system of  claim 29 , wherein the processor is further configured to:
 determine a second route associated with a second set of times within the three-dimensional spatial map;   determine a second set of positions of a second set of satellites associated with the second set of times based at least in part on the satellite ephemeris data;   simulate transmission of second satellite navigation signals from the second set of satellites to the second route at the associated second set of times;   determine a second set of transmission qualities associated with the second set of satellites to the second route associated with the second set of times.   
     
     
         31 . The system of  claim 30 , wherein the processor is further configured to:
 perform a comparison of the first set of transmission qualities with the second set of transmission qualities; and   determine a recommended route based at least in part on the comparison.   
     
     
         32 . The system of  claim 31 , wherein comparison is based at least in part on location based services quality. 
     
     
         33 . The system of  claim 31 , wherein to simulate further comprises simulating aGPS transmissions, DGPS transmissions, or WLAN transmissions. 
     
     
         34 . The system of  claim 29 , wherein the processor is further configured to:
 predict location-based cellular service quality; and   provide a rating of the route based at least in part on the predicted location-based cellular service quality.   
     
     
         35 . The system of  claim 29 , wherein the processor is further configured to transmit the first route to a robotic vehicle.