Bender-type重力卫星星座海潮混频特性研究

Ocean tide aliasing analysis of Bender-type constellation gravity mission

利用理论计算和数据模拟分析两种方法,深入研究了Bender-type卫星的混频特性.首先,根据卫星重力测量过程对高频信号的两步混频机制,计算了Bender-type每对卫星的混频频率;其次,根据数据驱动-频谱分析法,以8个主要海潮分量M_(2),N_(2),S_(2),K_(2),O_(1),P_(1),Q_(1),K_(1)单独作为输入信号,模拟了GRACE-type和Bender-type卫星任务,并对反演重力场时间序列进行频谱分析,确定各海潮分量在不同任务模式下的频率谱密度.研究发现:Bender-type卫星星座两对卫星的海潮混频并不存在耦合性,通过逐对分析每一对卫星单独观测引起的混频频率即可得到Bender-type卫星星座海潮混频频率.

The characteristics of Bender-type satellite mission were investigated through both theoretical and numerical strategies.To be specific,each of eight tidal constituent M_(2),N_(2),S_(2),K_(2),O_(1),P_(1),Q_(1),K_(1)was taken as input to simulate the GRACE-type and Bendertype gravity mission.Firstly,the aliasing frequencies of each scenario were estimated based on the orbit parameters and recovery period according to the two-step aliasing mechanism of satellite gravimetry sampling of high-frequency signals.Secondly,the aliasing frequencies of each tidal consistent was estimated by calculating the power spectral density of recovered gravity field time series.Results show that there is no coupling effect between two satellite pairs of the Bender-type constellation in terms of ocean tide aliasing.The aliasing frequencies of Bender-type constellation can be derived by the aliasing frequency of each satellite pair following the two-step aliasing mechanism.