利用小波分析识别空间目标的轨道机动

空间目标的轨道机动是与机械能的变化联系在一起的。机械能无法直接测量，只能通过空间目标的位置与速度计算。通过地面雷达可以得到空间目标的测距与测角信息，可以将其转为位置信息。空间目标的速度也不易直接测量，需要根据位置信息，通过微分平滑处理获得。由于测量噪声的影响，机动引起的机械能的变化淹没在噪声中，不容易识别。小波分析可以在一定程度上将淹没在噪声中的机械能变化揭示出来，提高轨道机动的识别能力。利用二进小波在不同尺度下分析机械能随时间的变化，尺度由小至大时真实信号含量增加，噪声含量受到抑制。观察小波系数曲线随小波分析尺度的变化趋势就可以快速判定是否存在轨道机动。仿真结果验证了识别方法的可行性。

Detection of space target orbit maneuver by wavelet analysis

The energy of space target is a character signal of orbit maneuver.There is no way to measure the energy of a space target directly,the energy must be calculated from the position and velocity.The distance,azimuth and elevation from space target to a earth station could be measured by a radar,the position of space target in inertial frame is translated from the measure value.The velocity is calculated from the fit curve of position.Then,the energy of space target is figured out from the position and velocity.The measure noise are enlarged so the change of energy due to orbit maneuver is submerged in the noise.The wavelets analysis in differential scale is used to keep track of time and frequency information of the energy.With the scale zoom out,the true signal is increased and noise is decreased.The existence of a orbit maneuver is judged by observe the trend of the wavelet transform result.The feasibility is verified by computer numerical simulation.