Patent ID: 8089401

Claim:
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.