| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To achieve appropriate position measurement corresponding to the position of an apparatus, for example, whether it is positioned indoors or outdoors. <P>SOLUTION: A CPU 20 acquires a signal corresponding to the intensity of light based on an electric signal due to the power generation of a photovoltaic circuit installed in a power supply circuit 34, and detects whether or not the acquired signal has a predetermined periodicity. If it is determined that the signal has a predetermined periodicity, the CPU 20 determines that a GPS signal processing part 18 should perform a position measurement in a two-dimensional measurement mode. If it is determined that the signal has no predetermined periodicity, the CPU 20 determines that the GPS signal processing part 18 should perform a position measurement in a three-dimensional measurement mode. The GPS signal processing part 18 acquires GPS frame data from a predetermined number of GPS satellites according to the determined measurement mode. <P>COPYRIGHT: (C)2010,JPO&INPIT</p> |
