Multimode microwave remote sensors are a new type of radar system that operates in SAR (synthetic aperture radar), scatterometer, altimeter, and spectrometer modes in a time-sharing manner according to the current task scheduled on small satellites. High flexibility through mode switching is the outstanding advantage of this new microwave remote sensor. Two or more small satellites operating in different operation modes can be networked to perform observations synchronously to provide excellent remote sensing performance. This paper focuses on a method to determine the radar parameters of the scatterometer mode since the frequency band and the platform height of this new of kind sensor are determined according to the requirement of the SAR mode, and their values are evidently different from the values of current scatterometers in orbit. The proposed method systematically presents the complete steps and related formulae of the radar parameter design of scatterometers and determines the signal bandwidth by optimization. A system simulation method of the scatterometer mode is further studied to determine the wind field inversion error and thus evaluate the rationality of the parameter design results. In contrast to the existing methods, which directly add noise to the backscatter coefficients, our method simulates the noisy echo of the scatterometer and then retrieves the wind field by estimated backscatter coefficients from the noisy echo. The performed simulation shows that, by using the designed system parameters, the multimode microwave remote sensor obtains wind field inversion accuracy, resolution and swath width comparable to those of the HY-2 satellite and the QuikSCAT satellite.

中文翻译：

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散射计模式多模微波遥感器参数设计方法及系统仿真研究


多模微波遥感器是根据小卫星当前任务调度，以分时方式工作在SAR（合成孔径雷达）、散射仪、高度计、光谱仪模式下的新型雷达系统。通过模式切换实现的高灵活性是这种新型微波遥感器的突出优点。两颗或多颗不同运行模式的小卫星可以组网同步进行观测，提供优异的遥感性能。由于这种新型传感器的频段和平台高度是根据SAR模式的要求确定的，其值与目前在轨的散射仪。该方法系统地给出了散射仪雷达参数设计的完整步骤和相关公式，并通过优化确定信号带宽。进一步研究了散射仪模式的系统仿真方法，确定风场反演误差，从而评价参数设计结果的合理性。与直接将噪声添加到后向散射系数的现有方法相比，我们的方法模拟散射仪的噪声回波，然后通过从噪声回波中估计的后向散射系数来反演风场。仿真结果表明，利用设计的系统参数，多模微波遥感器获得的风场反演精度、分辨率和测绘带宽度与HY-2卫星和QuikSCAT卫星相当。