Geolocation using guided surface waves
Disclosed are various approaches for navigation identifying one's current position. A navigation device receives a guided surface wave using a guided surface wave receive structure. The navigation device then receives a reflection of the guided surface wave using the guided surface wave receive structure. The navigation device calculates an amount of time elapsed between receiving the guided surface wave and receiving the reflection of guided surface wave. The navigation device then measures an angle between a wave front of the guided surface wave and a polar axis of the Earth. Finally the navigation device determines a location of the guided surface wave receive structure based at least in part on the angle between the wave front of the guided surface wave and the polar axis of the Earth the amount of time elapsed between receiving the guided surface wave and receiving the reflection of guided surface wave.
1. A system, comprising:
a charge terminal elevated over a lossy conducting medium;
a receiver network coupled between the charge terminal and the lossy conducting medium, the receiver network having a phase delay (Φ) that matches a wave tilt angle (Ψ) associated with a guided surface wave having a wave front incident at a complex Brewster angle of the lossy conducting medium, the wave tilt angle (Ψ) based at least in part upon characteristics of the lossy conducting medium in a vicinity of a guided surface wave receive structure;
a compass;
a processor;
a memory; and
an application stored in the memory and executable by the processor, wherein the application causes the system to perform at least the following actions when executed by the processor:
receive a guided surface wave using the guided surface wave receive structure;
receive a reflection of the guided surface wave using the guided surface wave receive structure;
calculate an amount of time elapsed between receiving the guided surface wave and receiving the reflection of guided surface wave;
measure an angle between a wave front of the guided surface wave and a polar axis of the Earth; and
determine a location of the guided surface wave receive structure based at least in part on:
the angle between the wave front of the guided surface wave and the polar axis of the Earth; and
the amount of time elapsed between receiving the guided surface wave and receiving the reflection of guided surface wave.
2. The system of claim 1 , wherein the application, when executed by the processor, further causes the system to at least:
measure a value for a magnetic dip at the location of the guided surface wave receive structure; and
determine the location of the guided surface wave receive structure is further based at least in part on the value of the magnetic dip.
3. The system of claim 1 , wherein the application, when executed by the processor, further causes the system to at least identify an approximate position of the guided surface wave receive structure based at least in part on an identity of a radio transmission tower within range of the guided surface wave receive structure; and
wherein causing the system to determine the location of the guided surface wave receive structure is further based at least in part on the approximate position of the guided surface wave receive structure.
4. The system of claim 1 , wherein the application, when executed by the processor, further causes the system to at least identify an approximate position of the guided surface wave receive structure based at least in part on an identity of a cellular network tower within range of the guided surface wave receive structure; and
wherein causing the system to determine the location of the guided surface wave receive structure is further based at least in part on the approximate position of the guided surface wave receive structure.
5. The system of claim 1 , wherein the application, when executed by the processor, further causes the system to at least identify an approximate position of the system based at least in part on inertial data associated with the system, wherein the inertial data is stored in the memory of the system; and
wherein causing the system to determine the location of the guided surface wave receive structure is further based at least in part on the approximate position of the system.
6. The system of claim 1 , wherein causing the system to determine a location of the system based at least in part on the amount of time elapsed between receipt of the guided surface wave and receipt of the reflection of the guided surface wave further comprises causing the processor to at least:
divide the amount of time in two to generate a halved amount of time;
multiply the halved amount of time by a speed of the guided surface wave to generate a distance between an antipode of a probe associated with the guided surface wave and the receiver network;
subtract the distance between the antipode and the guided surface wave receive structure from a value equal to half of the circumference of the Earth to generate a distance between the probe associated with the guided surface wave and the receiver network; and
set the location of the system along a circumference of a circle centered on the probe, wherein the circle has a radius equal to the distance between the probe and the system.
7. The system of claim 1 , wherein causing the system to determine a location of the system based at least in part on the amount of time elapsed between receipt of the guided surface wave and receipt of the reflection of the guided surface wave further comprises causing the processor to at least:
divide the amount of time in two to generate a halved amount of time;
multiply the halved amount of time by a speed of the guided surface wave to generate a distance between an antipode of a probe associated with the guided surface wave and the receiver network; and
set the location of the system along a circumference of a circle centered on the antipode, wherein the circle has a radius equal to the distance between the antipode and the system.
8. A method, comprising:
receiving a guided surface wave travelling along a terrestrial medium using a guided surface wave receive structure, the guided surface wave having a wave front incident at a complex Brewster angle of the terrestrial medium;
receiving a reflection of the guided surface wave using the guided surface wave receive structure;
calculating an amount of time elapsed between receiving the guided surface wave and receiving the reflection of the guided surface wave;
measuring an angle between the wave front of the guided surface wave and a polar axis of the Earth; and
determining a location of the guided surface wave receive structure based at least in part on:
the angle between the wave front of the guided surface wave and the polar axis of the Earth; and
the amount of time elapsed between receiving the guided surface wave and receiving the reflection of the guided surface wave.
9. The method of claim 8 , further comprising:
measuring a value for a magnetic dip at the location of the guided surface wave receive structure; and
determining the location of the guided surface wave receive structure is further based at least in part on the value of the magnetic dip.
10. The method of claim 8 , further comprising:
identifying an approximate position of the guided surface wave receive structure based at least in part on an identity of a cellular network tower within range of the guided surface wave receive structure; and
wherein determining the location of the guided surface wave receive structure is further based at least in part on the approximate position of the guided surface wave receive structure.
11. The method of claim 8 , further comprising:
identifying an approximate position of the guided surface wave receive structure based at least in part on an identity of a radio transmission tower within range of the guided surface wave receive structure; and
wherein determining the location of the guided surface wave receive structure is further based at least in part on the approximate position of the guided surface wave receive structure.
12. The method of claim 8 , further comprising:
identifying an approximate position of the guided surface wave receive structure based at least in part on inertial data associated with the guided surface wave receive structure; and
wherein determining the location of the guided surface wave receive structure is further based at least in part on the approximate position of the guided surface wave receive structure.
13. The method of claim 8 , wherein determining the location of the guided surface wave receive structure based at least in part on the amount of time elapsed between receiving the guided surface wave and receiving the reflection of the guided surface wave further comprises:
dividing the amount of time in two to generate a halved amount of time;
multiplying the halved amount of time by a speed of the guided surface wave to generate a distance between an antipode of a probe associated with the guided surface wave and the guided surface wave receive structure;
subtracting the distance between the antipode and the guided surface wave receive structure from a value equal to half of the circumference of the Earth to generate a distance between the probe associated with the guided surface wave and the guided surface wave receive structure; and
setting the location of the guided surface wave receive structure along a circumference of a circle centered on the probe, wherein the circle has a radius equal to the distance between the probe and the guided surface wave receive structure.
14. The method of claim 8 , wherein determining the location of the guided surface wave receive structure based at least in part on the amount of time elapsed between receiving the guided surface wave and receiving the reflection of the guided surface wave further comprises:
dividing the amount of time in two to generate a halved amount of time;
multiplying the halved amount of time by a speed of the guided surface wave to generate a distance between an antipode of a probe associated with the guided surface wave and the guided surface wave receive structure; and
setting the location of the guided surface wave receive structure along a circumference of a circle centered on the antipode, wherein the circle has a radius equal to the distance between the antipode and the guided surface wave receive structure.
15. An apparatus, comprising:
a guided surface wave receive structure configured to obtain electrical energy from a guided surface wave traveling along a terrestrial medium, the guided surface wave having a wave front incident at a complex Brewster angle of the terrestrial medium;
a processor;
a memory;
a compass; and
an application stored in the memory that, when executed by the processor, causes the apparatus to at least:
receive a guided surface wave using the guided surface wave receive structure;
receive a reflection of the guided surface wave using the guided surface wave receive structure;
calculate an amount of time elapsed between receiving the guided surface wave and receiving the reflection of the guided surface wave;
measure an angle between a wave front of the guided surface wave and a polar axis of the Earth; and
determine a location of the guided surface wave receive structure based at least in part on:
the angle between the wave front of the guided surface wave and the polar axis of the Earth; and
the amount of time elapsed between receiving the guided surface wave and receiving the reflection of guided surface wave.
16. The apparatus of claim 15 , wherein the application, when executed by the processor, causes the apparatus to at least:
measuring a value for a magnetic dip at the location of the guided surface wave receive structure; and
determining the location of the guided surface wave receive structure is further based at least in part on the value of the magnetic dip.
17. The apparatus of claim 15 , wherein causing the apparatus to determine a location of the apparatus based at least in part on the amount of time elapsed between receipt of the guided surface wave and receipt of the reflection of the guided surface wave further comprises causing the processor to at least:
divide the amount of time in two to generate a halved amount of time;
multiply the halved amount of time by a speed of the guided surface wave to generate a distance between an antipode of a probe associated with the guided surface wave and the guided surface wave receive structure; and
set the location of the apparatus along a circumference of a circle centered on the antipode, wherein the circle has a radius equal to the distance between the antipode and the apparatus.
18. The apparatus of claim 15 , wherein causing the apparatus to determine a location of the apparatus based at least in part on the amount of time elapsed between receipt of the guided surface wave and receipt of the reflection of the guided surface wave further comprises causing the processor to at least:
divide the amount of time in two to generate a halved amount of time;
multiply the halved amount of time by a speed of the guided surface wave to generate a distance between an antipode of a probe associated with the guided surface wave and the guided surface wave receive structure;
subtract the distance between the antipode and the guided surface wave receive structure from a value equal to half of the circumference of the Earth to generate a distance between the probe associated with the guided surface wave and the apparatus; and
set the location of the guided surface wave receive structure along a circumference of a circle centered on the probe, wherein the circle has a radius equal to the distance between the probe and the apparatus.
19. The apparatus of claim 15 , wherein the application, when executed by the processor, further causes the apparatus to at least identify an approximate position of the guided surface wave receive structure based at least in part on an identity of a cellular network tower within range of the guided surface wave receive structure; and
wherein causing the apparatus to determine the location of the guided surface wave receive structure is further based at least in part on the approximate position of the guided surface wave receive structure.
20. The apparatus of claim 15 , wherein the application, when executed by the processor, further causes the apparatus to at least identify an approximate position of the guided surface wave receive structure based at least in part on inertial data associated with the guided surface wave receive structure, wherein the inertial data is stored in the memory of the system; and
wherein causing the apparatus to determine the location of the guided surface wave receive structure is further based at least in part on the approximate position of the guided surface wave receive structure.