Patent ID: 7486232
Filing Date: 2009-02-03
Classification: G01S

Abstract:
1. A positioning apparatus comprising: a satellite selection indicator information generating device being configured to generate satellite selection indicator information based on satellite location information of an SPS (Satellite Positioning System) to select a plurality of SPS satellites used to position; a positioning device being configured to acquire positioning information by using said plurality of SPS satellites selected based on said satellite selection indicator information; an outputting device being configured to output said positioning information; a reception environment indicator information generating device being configured to generate reception environment indicator information of said SPS based on information of reception environment in receiving electric waves from said SPS, said reception environment indicator information being compared with said satellite selection indicator information with respect to positioning precision; and a positioning information evaluation device being configured to determine whether said positioning information is output to said outputting device or not, based on said satellite selection indicator information and said reception environment indicator information, said information of said reception environment being in an outdoor mode, if signal intensity of said electric waves from said SPS equals or exceeds a predetermined level, said information of said reception environment being in an indoor mode, if said signal intensity is less than said predetermined level, each of said plurality of SPS satellites being determined to have said information of said reception environment either in said outdoor mode or said indoor mode, said reception environment indicator information being based on a ratio of the number of said SPS satellites in said outdoor mode to the total number of said SPS satellites which are acquired, or the number of said SPS satellites in said indoor mode to the total number of said SPS satellites which are acquired.