对角加载对信号源数检测性能的改善

对角加载技术可抑制小特征值对自适应权值的影响来加速自适应波束形成器的收敛性以及抑制导向矢量误差的影响避免信号相消,该技术通常用于稳健的波束形成算法.基于对角加载技术,本文提出了一种信号源数目判定的改进方法,通过对角加载数据协方差阵,可以平滑小快拍数和空间色噪声时的噪声特征值分散程度从而减轻其对信号源数目估计的影响,证明了该估计器的强一致性,分析了加载量对信号源数目估计的影响.最后通过仿真以及实测数据比较了本文方法和已有方法的性能,验证了所提方法的有效性.

The Application of Galileo System on Spacecraft Attitude Determination

On Galileo system application,using Galileo signal to determinate the high dynamic spacecraft attitude is the key problems.Although GPS can determinate the user attitude,it is difficult to get the ambiguity resolution in single or dual- frequency carrier in real time.The paper establishes the algorithm model of the spacecraft attitude determination in detail according to the high dynamic spacecraft motion model.On the base of three carrier ambiguity resolution (TCAR) technique,a new method is proposed to solve the initial ambiguity problem of the high dynamic attitude determination.Combined the actual space mission projects with various orbits and attitudes,the simulation, statistics and analysis was fulfilled according to the Galileo navigation satellite constellation and signal structure.And the simulation results show that the performance of the ambiguity resolution and attitude determination can be improved.