Culled satellite ephemeris information based on limiting a span of an inverted cone for locating satellite in-range determinations

• US 20080036655A1
• Filed: 08/09/2006
• Published: 02/14/2008
• Est. Priority Date: 10/15/2004
• Status: Active Grant

• Current Assignee: TeleCommunication Systems Inc (Comtech Telecommunications Corporation)
• Original Assignee: TeleCommunication Systems Inc (Comtech Telecommunications Corporation)
• Inventors: Pitt, Lance Douglas, Lamprecht, Leslie Johann, Martin, Jeffrey Thomas
• Granted Patent: US 7,782,254 B2
• Time in Patent Office: Days
• US Class Current: 342/357.15
• CPC Class Codes: G01S 19/05 providing aiding data
• CPC Class Codes: G01S 19/258 relating to the satellite constellation, e.g. almanac, ephemeris data, lists of satellites in view
• CPC Class Codes: G01S 19/28 Satellite selection

Abstract

Locating satellites (e.g., GPS) are culled into a sub-plurality based largely on dwell time within an inverted cone above a relevant site in communication with a wireless device. A first inverted cone having a first base angle is defined above a first site, a second inverted cone having a second base angle is defined above a second site. If the second site is farther from an equator of Earth than the first site, then the second inverted cone is made to have a base angle larger than a base angle of the first inverted cone. If the first site is farther from the equator of Earth than the second site, then the first inverted cone is made to have a base angle larger than a base angle of the second inverted cone. The span of the inverted cone over the site closest to the equator may be limited.

Claims

1. A method of culling a plurality of locating satellites into a sub-plurality for communication by a plurality of wireless devices, comprising:

defining a first inverted cone above a first site, said first inverted cone having a first base angle; and

defining a second inverted cone above a second site, said second inverted cone having a second base angle;

wherein if said second site is farther from an equator of Earth than said first site, then said second inverted cone is made to have a base angle larger than a base angle of said first inverted cone; and

if said first site is farther from said equator of Earth than said second site, then said first inverted cone is made to have a base angle larger than a base angle of said second inverted cone.

2-22. -22. (canceled)