Apparatus and method for use in global position measurements

Abstract

Embodiments of the invention involve providing assistance data to a global position and navigation receiver, for example topographical data, such that the receiver can decide on a specific action depending on that data. The topographical data may include one or both of geographical data and architectural data. Geographical data may include information about natural formations, such as hills, valleys, forests, etc. Architectural data may include manmade formations, such as streets, buildings, bridges, etc. The receiver may then interpret and decide on a course of action for controlling the receiver base on the assistance data.

What is claimed is: 
     
         1 . An apparatus for a receiver having circuitry configured to receive signals from at least one source providing global positioning information, the apparatus comprising a receiver controller configured to compare an estimated position of the at least one source providing global positioning information with topographical data to determine whether a topographical feature defined in the topographical data would block receipt of the signals from the at least one source by the receiver and to modify navigational instructions provided by the receiver to a user to guide the user on a path that is less affected by a topographical feature that has been determined to block receipt of the signals. 
     
     
         2 . The apparatus of  claim 1  wherein the topographical data describes a topographical aspect of an area local to the receiver. 
     
     
         3 . The apparatus of  claim 1  wherein the topographical data includes at least one of data pertaining to at least one architectural feature in an area local to the receiver and data pertaining to at least one geographical feature in the area local to the receiver. 
     
     
         4 . The apparatus of  claim 1  wherein the topographical data includes for an area local to the receiver at least one of a width of at least one street, an orientation of at least one street, a height of at least one topographical feature, data indicative of a property of materials of at least one topographical feature, data indicative of a change in elevation, and altitude information. 
     
     
         5 . The apparatus of  claim 1  wherein the receiver controller is further configured to interpret the topographical data to make a decision to control operation of the receiver. 
     
     
         6 . The apparatus of  claim 1  wherein the receiver controller is further configured to use the topographical data to determine whether the at least one source providing global positioning information, which is above a horizon, is visible to the receiver. 
     
     
         7 . The apparatus of  claim 6  wherein when the at least one source providing global positioning information is visible to the receiver, the receiver controller is further configured to enable the receiver to search for the at least one source to acquire a signal. 
     
     
         8 . The apparatus of  claim 6  wherein when the at least one source providing global positioning information is not visible to the receiver, the receiver controller is further configured to stop the receiver from searching for the at least one source to acquire a signal. 
     
     
         9 . A global positioning system receiver configured to receive the signals from the at least one source providing global positioning information comprising the apparatus of  claim 1 . 
     
     
         10 . A method to use in a receiver having circuitry configured to receive signals from at least one source providing global positioning information, the method comprising:
 comparing an estimated position of the at least one source providing global positioning information with topographical data to determine whether a topographical feature defined in the topographical data would block receipt of the signals from the at least one source by the receiver; and   modifying navigational instructions provided by the receiver to a user to guide the user on a path that is less affected by a topographical feature that has been determined to block receipt of the signals.   
     
     
         11 . The method of  claim 10  wherein the topographical data describes a topographical aspect of an area local to the receiver. 
     
     
         12 . The method of  claim 10  further comprising using the topographical data to control power consumption of the receiver. 
     
     
         13 . The method of  claim 10  further comprising using the topographical data to determine if the receiver is positioned in a location that is influenced by multipath. 
     
     
         14 . The method of  claim 10  further comprising using the topographical data to control selection, acquisition, and tracking of the signals from the at least one source providing global positioning information. 
     
     
         15 . The method of  claim 10  further comprising using the topographical data to control position determination performed by the receiver. 
     
     
         16 . The method of  claim 10  further comprising using altitude data for controlling a determination of a receiver position estimate calculated by the receiver when the topographical data includes the altitude data for an area local to the receiver. 
     
     
         17 . A system for a receiver having circuitry configured to receive signals from at least one source providing global positioning information, the system comprising:
 a wireless enabled device located remotely from the receiver and configured to receive navigational instructions provided by the receiver; and   a receiver controller configured to compare an estimated position of the at least one source providing global positioning information with topographical data to determine whether a topographical feature defined in the topographical data would block receipt of the signals from the at least one source by the receiver and to modify the navigational instructions provided by the receiver to a user to guide the user on a path that is less affected by a topographical feature that has been determined to block receipt of the signals.   
     
     
         18 . The method of  claim 17  wherein the topographical data includes at least one of data pertaining to at least one architectural feature in an area local to the receiver and data pertaining to at least one geographical feature in the area local to the receiver. 
     
     
         19 . The method of  claim 17  wherein the topographical data includes for an area local to the receiver at least one of a width of at least one street, an orientation of at least one street, a height of at least one topographical feature, data indicative of a property of materials of at least one topographical feature, data indicative of a change in elevation, and altitude information. 
     
     
         20 . The method of  claim 17  further comprising using the topographical data to control operation of the receiver.