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日本SELENE月球探测计划和卫星间多普勒跟踪的数学模型
平劲松
1,2 河野裕介 1,2 河野宣之 2,3
花田英夫 3 松本晃治 3 RISE Group 3
(1. 北京师范大学天文系 北京 100875)
(2. 日本综合研究大学院大学数理学系 东京 181-8588)
(3. 日本国立天文台地球自转研究分部 岩手县水泽 023-0861)
摘 要
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日本月球探测计划(SELENE)定于2004年夏季利用HIIa
火箭发射一组共3颗绕月人造卫星。他们是主卫星、跟踪中继卫星和空间VLBI电波源。其主要科学目标之一是利用对绕月卫星的多普勒跟踪数据精确测定月球重力场，研究月球的起源与演化。SELENE计划中实现这个科学目标的关键技术是引入中继卫星，目的在于当处于低轨道的主卫星飞行到月球背面地面观测站无法观测时，采用卫星间跟踪方法(SST)，建立地面站与主卫星之间的联系，以得到月球背面重力场的直接测量数据。介绍了几种典型的四程卫星间多普勒跟踪模式和相应的数学模型，并针对SELENE计划中采用的特殊四程多普勒跟踪模式建立了卫星相对观测站速度与跟踪信号多普勒频移之间的转换关系。提出了利用GEODYN
II定轨分析软件处理SELENE多普勒跟踪数据的流程。
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SELENE
Mission: Mathematical Model for SST Dopler Measurements
Ping
J 1,2 Kono Y 1,2
Kawano N 2,3
Hansda H 3
Matsumoto K 3 RISE Group 3
(1. Department of Astronomy, Beijing Normal University, Beijing 100875)
(2. Department of Astronomy Science, the Graduate University for Advanced
Studies, Tokyo, 181-8588, Japan)
(3. Division of Earth Rotation, NAO, Hoshigaoka Machi, Mizusawa-shi, 023-0861,
Japan)
Abstract
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Japanese lunar exploration mission, SELENE, has been planned to be
launched into space by using H II-a rocket in the Summer of 2004. This
mission is composed of 3 subsatellites, a main lunar orbiter, a relay
satellite and a free flying VLBI radio source. One of its main
scientific objectives is the estimation of high order and degree
spherical harmonic coefficients for the lunar gravity field. Different
tracking methods will be employed in SELENE. The key tracking method
is 4 way Satellite-to-Satellite Tracking (SST) technique. By this way,
the tracking data can be obtained through the relay satellite when the
low altitude main orbiter is flying at the far-side of the Moon and
can not be“seen” from the Earth. To success the historical
tracking data, a complete coverage of Doppler traking from an orbiter
at sufficiently low altitude with high tracking accuracy can be
obtained. The 4 way SST has various configurations. For SELENE, The
SST tracking mode is introduced here, the mathematical relation
between range rate and 4 way Doppler count number is established, and
a data processing stream frame by using GEODYN II is suggested.
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