Culled satellite ephemeris information for quick, accurate assisted locating satellite location determination for cell site antennas
Locating satellites (e.g., GPS) are culled into a preferred group having a longest dwell time based on a time passing through an ellipsoid arc path through a cone of space, and communicated to mobile devices within a particular region (e.g., serviced by a particular base station). The base station may select those locating satellites that are visible, or more preferably those locating satellites currently within a cone of space above the relevant base station are selected for communication to a mobile device within the service area of the base station. The inverted cone of space may be defined for each antenna structure for any given base station, and each has 360 degrees of coverage, or less than 360 degrees of coverage, with relevant locating satellites. Thus, cell sites may be specifically used as reference points for culling the ephemeris information used to expedite Assisted GPS location determinations.
1. A method of culling a plurality of locating satellites into a sub-plurality of locating satellites, comprising:
receiving, at a physical base station receiver, satellite signals from a plurality of locating satellites;
culling said plurality of locating satellites into a first sub-plurality of locating satellites, said first sub-plurality of locating satellites being only those satellites from said plurality of locating satellites within view of said physical base station receiver;
computing an arc defining a variable inverted cone above said physical base station receiver as a function of a latitude of said physical base station receiver, a base angle of said variable inverted cone increasing as a function of a distance from the equator of the Earth;
culling said first sub-plurality of locating satellites into a second sub-plurality of locating satellites, said second sub-plurality of locating satellites being only those satellites from said first sub-plurality of locating satellites within said variable inverted cone; and
culling said second sub-plurality of locating satellites into a third sub-plurality of locating satellites, said third sub-plurality of locating satellites being only those satellites from said second first sub-plurality of locating satellites having longest dwell times within said variable inverted cone.
2. The method of culling a plurality of locating satellites into a sub-plurality of locating satellites according to claim 1 , wherein:
said physical base station receiver corresponds to a wireless base station.
3. The method of culling a plurality of locating satellites into a sub-plurality of locating satellites according to claim 2 , wherein:
a location of said physical base station receiver corresponds to a surveyed location of a cellular cell site.
4. The method of culling a plurality of locating satellites into a sub-plurality of locating satellites according to claim 1 , wherein:
said variable inverted cone is normal to Earth.
5. The method of culling a plurality of locating satellites into a sub-plurality of locating satellites according to claim 1 , wherein:
said physical base station receiver is a cellular phone base station.
6. The method of culling a plurality of locating satellites into a sub-plurality of locating satellites according to claim 1 , wherein:
said culling is performed by a mobile device.
7. The method of culling a plurality of locating satellites into a sub-plurality of locating satellites according to claim 1 , wherein:
said culling is performed by a wireless base station in communication with a wireless device.
8. The method of culling a plurality of locating satellites into a sub-plurality of locating satellites according to claim 1 , wherein:
each of said plurality of locating satellites is a Global Positioning Satellite (GPS) satellite.
9. The method of culling a plurality of locating satellites into a sub-plurality of locating satellites according to claim 1 , further comprising:
determining a position of said third sub-plurality of locating satellites with respect to a third sub-plurality of locating satellite's apogee;
wherein said third sub-plurality of locating satellites is further culled based on said determined position of said third sub-plurality of locating satellites with respect to each of said third sub-plurality of locating satellites' apogee.
10. The method of culling a plurality of locating satellites into a sub-plurality of locating satellites according to claim 1 , wherein:
said third sub-plurality of locating satellites is four of said second sub-plurality of locating satellites having said longest dwell times within said variable inverted cone.