Effect of Phase Pattern of Antennas Onboard Flying Spin Satellites on Doppler Measurements
Effect of Phase Pattern of Antennas Onboard Flying Spin Satellites on Doppler Measurements
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DOI：
10.1109/taes.2011.5705683
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发表时间：
2011-01
影响因子：
4.4
通讯作者：
Qinghui Liu;Koji Matsumoto;T. Iwata;N. Namiki;H. Noda;H. Hanada;Y. Ishihara;S. Goossens;F. Kikuchi;K. Asari;S. Tsuruta;T. Ishikawa;S. Sasaki;T. Takano
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文献类型：
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作者：
Qinghui Liu;Koji Matsumoto;T. Iwata;N. Namiki;H. Noda;H. Hanada;Y. Ishihara;S. Goossens;F. Kikuchi;K. Asari;S. Tsuruta;T. Ishikawa;S. Sasaki;T. Takano
报道了自旋飞行卫星天线相位图对多普勒测量结果的影响。相位图意味着波阵面有偏离完美球度的情况，它表示为天线周围角位置的函数。本文分析了用于日本“月亮女神”（SELENE）月球任务的两颗飞行自旋卫星Rstar和Vstar上的偶极子和贴片天线的相位图对2路和4路多普勒测量的影响，发现自旋频率的高次谐波在多普勒频率中高达26阶。我们开发了一种低通滤波器（LPF），使用凯撒窗口，并根据经验确定了最佳参数，以消除相位模式的影响，并精确保存有关月球重力场的信息。我们用LPF对SELENE的2路和4路多普勒数据进行了处理。使用LPF后，2路多普勒测量的精度达到了0.001 Hz左右，并且首次从4路多普勒数据中检测到反映月球远侧重力场的信号。我们还提出了一种利用多普勒频率变化估计卫星天线相位响应的方法。为了估计多普勒频率变化，采用滤波技术提取残差信号中感兴趣的谐波，由此导出天线相位图。
The effect of the phase patterns of antennas onboard flying spin satellites on the Doppler measurements is reported. Phase patterns mean that there are deviations in wave fronts from perfect sphericity, expressed as a function of the angular position around the antenna. We analyzed what effect the phase patterns of dipole and patch antennas onboard two flying spin satellites, Rstar and Vstar, used in the Japanese lunar mission, SELENE (KAGUYA), had on 2-way and 4-way Doppler measurements, and detected higher harmonics in the spin frequency up to an order of 26 in the Doppler frequency. We developed a low-pass filter (LPF) using a Kaiser window, with the optimal parameters empirically determined, to remove the influence of phase patterns and to precisely conserve information on the lunar gravity field. We processed the 2-way and 4-way Doppler data of SELENE by using LPF. After using LPF, a high degree of accuracy of about 0.001 Hz was achieved for the 2-way Doppler measurements, and signals that reflected the gravity field on the far side of the Moon were first detected from the 4-way Doppler data. We also suggested a method for estimating the phase response of satellite antennas using the Doppler frequency variations. In order to estimate the Doppler frequency variation, a filtering technique was adopted to extract the harmonics of interest in the residual signal, from which the antenna phase pattern was derived.