| 摘要: |
| 本文根据海浪波谱仪的信号形成机制，总结了机载波谱仪反演海浪的流程。利用机载波谱仪回波数据，通过自相关和互相关两种功率谱估计方法，反演了二维海浪谱。最后通过与浮标测量的二维海浪谱进行对比，验证了该机载波谱仪探测二维海浪谱的有效性。结果发现无论采用自相关函数还是互相关函数进行功率谱估计，得到的主波波长和有效波高与实际二维海浪谱基本一致。互相关函数法得到的交叉谱能去除180°模糊现象，其在计算有效波高时相对于自相关函数会稍微偏小。在计算斜率方差时可以采用5°-12°入射角范围的后向散射系数进行公式拟合，因此定标与否并不影响最后的二维海浪谱结果，未来星载波谱仪只有靠多波束联合才能实现。 |
| 关键词: 波谱仪 二维海浪谱 |
| DOI： |
| 分类号:P731.22; TP732．1 |
| 基金项目:国家自然科学基金项目（面上项目，重点项目，重大项目） |
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| The retrieval method of ocean wave spectrum from airborne spectrometer and the validation |
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lixiuzhong
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Nanjing University Of Information Science And Technology
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| Abstract: |
| Based on the signal formation principle of ocean wave spectrometer, the ocean wave retrieval flow is summarized. By the spectra estimation methods from auto-correlation function and cross-correlation function, the two-dimensional ocean wave spectrum is obtained. At last, after the comparison between the spectrum from the buoy and that retrieved from spectrometer, the effectiveness of detecting two-dimensional spectrum from airborne spectrometer is conducted. It is shown that in the environments of the flight, the result of the two methods in retrieving ocean wave spectrum are consistent with that from the buoy. From the cross spectrum the ambiguity of 180° is excluded, although the significant wave height is smaller than that from auto-correlation method. When the sea slope variance is calculated, the radar backscattering coefficients of the incidence angles at 5°-12° are fitted, thus it make no difference whether it is calibrated or not, but the future spaceborne spectrometer can attain it by multi-beam joint. |
| Key words: Spectrometer Two-dimensional ocean wave spectrum |