| 摘要 |
PROBLEM TO BE SOLVED: To intuitively understand an obstruction interrupting radio wave by detecting the position of a satellite which can be received or cannot be received and indicating it in such a manner that it may be discriminating easily. SOLUTION: An advancing-direction operation part 12 detects the radio wave doppler shift of every satellite from the output signals of a GPS reception part 11 which receives radio waves of every satellite through an antenna 10 and it operates the advancing direction P of a mobile body, then it sends the direction to an indication control part 14. In addition, a satellite information detection part 13 detects the position and reception status of a satellite which can be received, according to the output signal 11. The control part 14 finds relative angles between the positions P and respective satellites in order to prepare a newly corrected data for indication. The indication part 15 draws the sky position of the respective satellites by using the data and indicates it together with the reception status. Then, in case where there is no satellite that can be received, the value just before the reception level becomes lower among the results that the detection part 13 stores every time is adopted so as to find out the position of a satellite which cannot be received and draw it. At this time, it is indicated by different colors, etc., so that it may be easily discriminated, thereby understanding intuitively an abstruction interrupting the radio wave from the satellite. |
