ATMOSPHERIC DELAY ESTIMATION AND COMPENSATION FOR SINGLE-FREQUENCY RECEIVERS
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 . A method comprising:
receiving, from a central location system, measures of atmospheric delay from a plurality of dual-frequency receivers distributed over a geographic region;
generating, by the central location system, an atmospheric delay model for the geographic region based on the received measures of atmospheric delay;
receiving, from a single-frequency receiver within the geographic region, an approximate location of the single-frequency receiver;
determining, by the central location system, an atmospheric delay for the approximate location of the single-frequency receiver using the generated atmospheric delay model;
providing the determined atmospheric delay to the single-frequency receiver; and
computing, by the single-frequency receiver, a refined location of the single-frequency receiver based on the determined atmospheric delay and the approximate location of the single-frequency receiver.
2 . The method of claim 1 , wherein the atmospheric delay comprises an ionospheric delay.
3 . The method of claim 1 , wherein the atmospheric delay comprises an instrumental delay.
4 . The method of claim 1 , wherein the atmospheric delay comprises a tropospheric delay.
5 . The method of claim 1 , wherein receiving measures of atmospheric delay further comprises:
receiving, from each of the plurality of dual-frequency receivers, an instrumental delay and an ionospheric delay; and
filtering the instrumental delays and ionospheric delays, wherein the filtered instrumental delays and ionospheric delays are used to generate the atmospheric delay model.
6 . The method of claim 1 , further comprising:
generating a topographical map of the atmospheric delay over the geographic region based on the atmospheric delay model; and
generating, on a device of a user, a user interface, the user interface including the topographical map.
7 . The method of claim 1 , wherein generating the atmospheric delay model further comprises:
identifying, for each of the plurality of dual-frequency receivers, a time differential between timestamps of two signals of different transmission frequencies received by the dual-frequency receiver.
8 . A method comprising:
receiving, from a central location system, measures of atmospheric delay from a plurality of dual-frequency receivers distributed over a geographic region;
generating, by the central location system, an atmospheric delay model for the geographic region based on the received measures of atmospheric delay;
providing the determined atmospheric delay model to a single-frequency receiver; and
determining, by the single-frequency receiver, a refined location of the single-frequency receiver using the determined atmospheric delay model and an approximate location of the single-frequency receiver.
9 . A non-transitory computer-readable storage medium containing computer program code that, when executed by a hardware processor, causes the hardware processor to perform steps comprising:
receiving, from a central location system, measures of atmospheric delay from a plurality of dual-frequency receivers distributed over a geographic region;
generating, by the central location system, an atmospheric delay model for the geographic region based on the received measures of atmospheric delay;
receiving, from a single-frequency receiver, an approximate location of the single-frequency receiver;
determining, by the central location system, an atmospheric delay for the approximate location using the generated atmospheric delay model;
providing the determined atmospheric delay to the single-frequency receiver; and
computing, by the single-frequency receiver, a refined location using the determined atmospheric delay.
10 . The non-transitory computer-readable storage medium of claim of claim 9 , wherein the atmospheric delay comprises an ionospheric delay.
11 . The non-transitory computer-readable storage medium of claim of claim 9 , wherein the atmospheric delay comprises a tropospheric delay.
12 . The non-transitory computer-readable storage medium of claim of claim 9 , wherein receiving measures of atmospheric delay further comprises:
receiving, from each of the plurality of dual-frequency receivers, an instrumental delay and an ionospheric delay; and
filtering the instrumental delays and ionospheric delays, wherein the filtered instrumental delays and ionospheric delays are used to generate the atmospheric delay model.
13 . The non-transitory computer-readable storage medium of claim of claim 9 , wherein the program code, when executed by the processor, causes the processor to perform further steps comprising:
generating a topographical map of the atmospheric delay over the geographic region based on the atmospheric delay model; and
generating, on a device of a user, a user interface, the user interface including the topographical map.
14 . The non-transitory computer-readable storage medium of claim of claim 9 , wherein generating the atmospheric delay model further comprises:
identifying, for each of the plurality of dual-frequency receivers, a time differential between timestamps of two signals of different transmission frequencies received by the dual-frequency receiver.
15 . A system comprising:
a hardware processor; and
a non-transitory computer-readable medium containing instructions that, when executed by the hardware processor, cause the hardware processor to:
receive, from a central location system, measures of atmospheric delay from a plurality of dual-frequency receivers distributed over a geographic region;
generate, by the central location system, an atmospheric delay model for the geographic region based on the received measures of atmospheric delay;
receive, from a single-frequency receiver, an approximate location of the single-frequency receiver;
determine, by the central location system, an atmospheric delay for the approximate location using the generated atmospheric delay model;
provide the determined atmospheric delay to the single-frequency receiver; and
compute, by the single-frequency receiver, a refined location using the determined atmospheric delay.
16 . The system of claim 15 , wherein the atmospheric delay comprises an ionospheric delay.
17 . The system of claim 15 , wherein the atmospheric delay comprises a tropospheric delay.
18 . The system of claim 15 , wherein receiving measures of atmospheric delay further comprises:
receiving, from each of the plurality of dual-frequency receivers, an instrumental delay and an ionospheric delay; and
filtering the instrumental delays and ionospheric delays, wherein the filtered instrumental delays and ionospheric delays are used to generate the atmospheric delay model.
19 . The system of claim 15 , further containing instructions that cause the hardware processor to:
generate a topographical map of the atmospheric delay over the geographic region based on the atmospheric delay model; and
generating, on a device of a user, a user interface, the user interface including the topographical map.
20 . The system of claim 15 , wherein generating the atmospheric delay model further comprises:
identifying, for each of the plurality of dual-frequency receivers, a time differential between timestamps of two signals of different transmission frequencies received by the dual-frequency receiver.