2021-12-05T17:40:23Zhttps://jaxa.repo.nii.ac.jp/?action=repository_oaipmhoai:jaxa.repo.nii.ac.jp:000448412021-03-17T09:19:23Z01887:0189301896:01898:01913:01917
超低高度人工衛星DASのための加速度計を用いた搭載型航法システムjpnhttp://id.nii.ac.jp/1696/00044835/Technical ReportAn Onboard Navigator for the Extremely Low Altitude Satellite DAS Utilizing Accelerometers森, 英彦MORI, Hidehiko航空宇宙技術研究所National Aerospace Laboratory(NAL)航空宇宙技術研究所報告 = Technical Report of National Aerospace Laboratory TR-587587391979-10The main mission of the DAS(Dive and Ascent Satellite) flying at an extremely low altitude with perigee near 110km is to measure the atmospheric characteristics directly at the bottom of the ionosphere. Continuous observation and prediction of the perigee altitude is required to attain the mission. This paper proposes an onboard navigation system utilizing accelerometer data in the neighborhood of perigee. Simplified algorithms applied to a small size onboard computer are presented. The solutions of the Euler Hill equations for the perturbation of orbits due to the earth’s oblateness and air drag are examined in comparison with the simulated results obtained from the numerical integration of the rigorous differential equations. A method for approximating Jacchia’s atmospheric density model by a simple function of altitude, with the exsospheric temperature as a parameter, is described. Then, an analytic formula to express the air drag on the satellite in the neighborhood of perigee is presented. The time of perigee passage, the perigee radius and the semi major axis are derived directly from the formula utilizing the accelerometer data concerning the maximum drag force. The method of least squares applied to this formula reveals the estimation of the parameters of the approximated density model with the accelerometer data in 4 minutes passing perigee, as well as the estimation of orbital elements, except the longitude of ascending node, with the accelerometer data in 6 minutes passing perigee.0389-4010https://jaxa.repo.nii.ac.jp/?action=repository_action_common_download&item_id=44841&item_no=1&attribute_id=31&file_no=1資料番号: NALTR0587000レポート番号: NAL TR-5872020-01-29