Stratospheric position, navigation, and timing system
Disclosed in some examples are methods, systems, devices, and machine-readable mediums for providing a PNT system provided by stratospheric balloons. This stratospheric PNT system (SPNTS) replaces the space-segment of a standard PNTS with a stratospheric segment comprising one or more stratospheric balloons that provide PNTS signals usable to determine timing, positioning, and/or navigation for user devices.
1. A device comprising:
a balloon;
a computing device coupled to the balloon, the computing device comprising:
a hardware processor configured to:
determine a geolocation of the balloon;
create almanac data comprising locations of a plurality of other balloons based upon peer-to-peer messages exchanged with the plurality of other balloons; and
a transceiver configured to:
broadcast a signal based upon the geolocation that includes data useable by a user segment receiver for trilateration as part of resolving its global position, the signal a same format and frequency as signals sent by a Global Navigation Satellite System (GNSS), the signal including the almanac data.
2. The device of claim 1 , wherein the transceiver is further configured to broadcast a ranging code.
3. The device of claim 1 , wherein the hardware processor is configured to determine the geolocation of the balloon based upon geolocation signals received from a plurality of ground based reference signals.
4. The device of claim 1 , wherein the computing device coupled to the balloon includes a sensor, and wherein the hardware processor is configured to determine the geolocation of the balloon based upon an output of the sensor.
5. The device of claim 4 , wherein the sensor is an inertial measurement unit.
6. The device of claim 4 , wherein the sensor is a barometer.
7. The device of claim 4 , wherein the sensor is an optical sensor.
8. The device of claim 4 , wherein the sensor is one of: a directional RF sensor array, a magnetometer, RADAR, radio navigation aids.
9. The device of claim 4 , wherein the hardware processor is configured to determine the geolocation of the balloon by inputting the output of the sensor into a Bayesian filter to produce estimated geolocation coordinates.
10. The device of claim 4 , wherein the hardware processor is configured to determine the geolocation of the balloon from a message sent by a ground-based station and the output of the sensor.
11. The device of claim 1 , comprising an atomic clock.
12. The device of claim 11 , wherein the hardware processor is configured to synchronize the atomic clock to a plurality of atomic clocks in a plurality of other balloons.
13. A method of providing a signal for Positioning, Navigation, or Timing, the method comprising:
from a computing device coupled to a balloon, using a hardware processor to perform operations of:
determining a geolocation of the balloon;
creating almanac data comprising locations of a plurality of other balloons based upon peer-to-peer messages exchanged with the plurality of other balloons; and
broadcast a signal based upon the geolocation that includes data useable by a user segment receiver for trilateration as part of resolving its global position, the signal a same fomrn.t and frequency as signals sent by a Global Navigation Satellite System (GNSS), the signal including the almanac data.
14. The method of claim 13 , wherein the operations of determining the geolocation of the balloon comprises determining the geolocation of the balloon based upon geolocation signals received from a plurality of ground-based reference signals.
15. The method of claim 13 , wherein the operations of determining the geolocation of the balloon comprises determining the geolocation of the balloon based upon an output of a sensor that is both communicatively coupled to the hardware processor and attached to the balloon.
16. The method of claim 15 , wherein the sensor is one or more of: an inertial measurement unit, a barometer, an optical sensor, a celestial sensor, a directional RF sensor array, a magnetometer, radio detection and ranging (RADAR), and a radio navigational aid.
17. The method of claim 15 , wherein the operations of determining the geolocation of the balloon comprises determining the geolocation of the balloon by inputting the output of the sensor and a second sensor into a Bayesian filter to produce estimated geolocation coordinates.
18. The method of claim 15 , wherein the operations of determining the geolocation of the balloon comprise determining the geolocation of the balloon from a message sent by a ground-based station and the output of the sensor.