The Doppler Characteristics of Sea Echoes Acquired by Motion Radar
The Doppler Characteristics of Sea Echoes Acquired by Motion Radar
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DOI：
10.3390/rs15194888
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发表时间：
2023-10
期刊：
影响因子：
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通讯作者：
Pengbo Du;Yunhua Wang;Xin Li;Jianbo Cui;Yanmin Zhang;Qian Li;Yushi Zhang
中科院分区：
文献类型：
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作者：
Pengbo Du;Yunhua Wang;Xin Li;Jianbo Cui;Yanmin Zhang;Qian Li;Yushi Zhang
海面回波的多普勒特性反映了海面的时变特性，可用于海洋动力学参数的反演和目标检测。在机载、星载和舰载雷达平台上，雷达随平台沿着运动，同时照射海面。在这种情况下，雷达波束照射的海面面积随着运动而迅速变化，不同时刻后向散射回波的相干性显著降低。因此，回波的多普勒特性也会受到雷达运动的影响。目前，采用数值方法模拟海面微波散射场的多普勒谱需要大量的计算量。针对这一问题，提出了一种基于子散射面元的运动微波雷达海面回波多普勒谱模拟方法。通过与SSA方法计算结果的比较，验证了该方法的有效性和优越性。该方法综合考虑了雷达运动、雷达波束宽度、入射角和热噪声对多普勒特性的影响。仿真结果表明，在潜视运动平台上，雷达获取的海面回波谱带宽有所变窄。
The Doppler characteristics of sea surface echoes reflect the time-varying characteristics of the sea surface and can be used to retrieve ocean dynamic parameters and detect targets. On airborne, spaceborne and shipborne radar platforms, radar moves along with the platforms while illuminating the sea surface. In this case, the area of the sea surface illuminated by radar beam changes rapidly with the motion, and the coherence of the backscattered echoes at different times decreases significantly. Therefore, the Doppler characteristics of the echoes would also be affected by the radar motion. At present, the computational requirements needed to simulate the Doppler spectrum of the microwave scattering field from the sea surface based on numerical methods are huge. To overcome this problem, a new method based on the sub-scattering surface elements has been proposed to simulate the Doppler spectrum of sea echoes acquired by a moving microwave radar. A comparison with the results evaluated by the SSA demonstrate the availability and superiority of the new method proposed by us. The influences induced by radar motion, radar beamwidth, incident angle, and thermal noise on the Doppler characteristics are all considered in this new method. The simulated results demonstrate that the spectrum bandwidth of sea surface echoes acquired by radar on the dive staring motion platform becomes somewhat narrower.