现需要在高度为600~700KM范围内，回归周期为30天的太阳同步轨道上布置一颗L波段的合成孔径雷达卫星。

1. 请设计合适的轨道参数，并仿真对应轨道下一个运行周期内星下点轨迹图（纬度和经度两个图）；

2. 计算多普勒中心频率，多普勒调频率与纬度的关系图（设姿态角为0°，天线视角20°~60°，推荐35°）；

3. 按高斯投影方式，将星下点轨迹图投影到地图坐标上。-Now requires a height of 600 ~ 700KM range, return period of 30 days are arranged on a sun-synchronous orbit L-band Synthetic Aperture Radar satellites. 1 Please design the appropriate orbital parameters and simulate the corresponding orbit within the next operating cycle nadir trajectories (latitude and longitude two graphs)　2. Calculate the Doppler center frequency, Doppler frequency and the relationship between latitude Figure (set attitude angle is 0, the antenna angle of 20 to 60, recommended 35)　3 Press Gauss projection, the nadir trajectories projected onto the map coordinates.