Antenna selection in a positioning system
A positioning system includes a positioning device with a local antenna. One or more remote antennas are also connected to the device. The system selects one or more antennas to use in determining a position based at least in part on an orientation of the device. Other factors which may be used in selection include: a particular environment of the device, manual override, signal quality, and a stage in a workflow process.
1. A positioning system including:
i. a positioning device having a local GPS antenna;
ii. at least one remote GPS antenna; and
iii. a selection arrangement configured to select one or more of the GPS antennas to use in determining a position, the selection being based at least in part on an orientation of the device.
2. A positioning system as claimed in claim 1 , wherein the orientation is an inclination of the device.
3. A positioning system as claimed in claim 2 , wherein the positioning device includes an inclinometer arranged to determine the inclination of the device.
4. A positioning system as claimed in claim 1 , further including a sensor arranged to determine when the positioning device is in a particular environment, wherein the selection is based in part on whether the positioning device is in the particular environment.
5. A positioning system as claimed in claim 4 , wherein the particular environment is one of a cradle environment; a holster environment; and a handheld environment.
6. A positioning system as claimed in claim 1 , further including a user interface arranged to enable manual override of the selection, such that a user can manually select one or more of the GPS antennas to use in determining a position.
7. A positioning system as claimed in claim 1 , arranged to detect a signal quality from one or more of the GPS antennas, wherein the selection is based in part on the signal quality detected.
8. A positioning system as claimed in claim 7 , wherein the signal quality is detected as dilution of precision (DOP).
9. A positioning system as claimed in claim 1 , wherein the selection is based in part on a stage reached in a workflow process of the positioning device.
10. A positioning system as claimed in claim 1 , wherein the positioning device includes a camera and laser distance meter.
11. A positioning system as claimed in claim 1 , arranged to track the position of the positioning device.
12. A positioning system as claimed in claim 1 , wherein at least one remote antenna is connected to the positioning device by a wired connection.
13. A positioning system as claimed in claim 1 , wherein at least one remote antenna is connected to the positioning device by a wireless connection.
14. A positioning system as claimed in claim 1 , wherein at least one remote antenna is arranged to be mounted on one of: a user's backpack; a user's hat or helmet; and a vehicle.
15. A positioning system as claimed in claim 1 , wherein the selection arrangement includes:
a processor arranged to receive orientation signals indicative of the orientation of the device and to select one or more antennas based on the orientation signals; and
a switching arrangement for switching between the antennas.
16. A method of controlling a positioning system, including:
i. determining an orientation of a positioning device having a local GPS antenna;
ii. selecting one or more GPS antennas from the local GPS antenna and one or more remote GPS antennas, the selection being based at least in part on the orientation of the device; and
iii. determining a position using the selected antenna(s).
17. A method as claimed in claim 16 , wherein the orientation is an inclination of the device.
18. A method as claimed in claim 16 , further including determining whether the positioning device is in a particular environment, wherein the selection is based in part on whether the positioning device is in the particular environment.
19. A method as claimed in claim 18 , wherein the particular environment is one of a cradle environment; a holster environment; and a handheld environment.
20. A method as claimed in claim 16 , further including enabling a user to manually override the selection, such that a user can manually select one or more of the GPS antennas to use in determining a position.
21. A method as claimed in claim 16 , including detecting a signal quality from one or more of the GPS antennas, wherein the selection is based in part on the signal quality.
22. A method as claimed in claim 21 , wherein the signal quality is detected as dilution of precision (DOP).
23. A method as claimed in claim 16 , wherein the selection is based in part on a stage reached in a workflow process of the positioning device.
24. A method as claimed in claim 16 , including tracking the position of the positioning device.
25. A method as claimed in claim 16 , wherein at least one remote antenna is selected for determining the position of the device, including:
correcting for the offset between the position of the remote antenna and the position of the positioning device.
26. A method as claimed in claim 25 , wherein correcting for the offset includes receiving manual input from a user, the input representing the offset.
27. A method as claimed in claim 25 , wherein correcting for the offset includes determining the direction of the offset based on the reading from a compass in the positioning device and an assumption that the positioning device is pointing away from the external antenna.
28. A method as claimed in claim 25 , wherein correcting for the offset includes determining the magnitude of the offset using a time of flight measurement between the remote antenna and the positioning device.
29. A method as claimed in claim 25 , wherein the positioning device includes an orientation sensor and a distance meter and wherein correcting for the offset includes using the orientation sensor and distance meter to determine the orientation and magnitude of the offset.