| 摘要 |
PROBLEM TO BE SOLVED: To make it possible to minimize an error range which requires a search when a return to a stored position is made by measuring error ranges by event positions and managing them. SOLUTION: A data processing part 4 processes position measurement data and other data from a DGPS reception part 3 and outputs position measurement information and information on error ranges in real time. Namely, when an event switch is pressed, the processing part 4 sequentially measures a current error range from the position of a satellite, signal precision, the age of differential (D) data, etc., and stores the current measured position and data on the error range in an event memory 7. A display part 5 displays the current measured position in real time, and also displays the event position stored in the memory 7 and its error range together with the current position thorugh user's operation. The error range in this case is a little smaller than a general nominal error range and when a return to the event position is made, a search range can be made small. |
