波谱仪多波束联合遥感反演海浪方向谱方法研究

The CFOSAT(Chinese French Ocean SATellite) payload the first spectrometer all over the world will be launched around 2014, which will provide the abundant directional ocean wave spectra data for globalized oceanic research. Spectrometer has 5 beams for estimating the wave field. Due to the complexity of wave modulation mechanism on some beams, the proposed retrieval mode is only adapted for the 10°beam. Now the spectrometer is lack of the retrieval model and method in other beams. This project will use the method about look-up table and joint multi-beam to study the retrieval method of ocean wave spectra. Based on the model in 10°, we will retrieve the wave spectra in different beams from the spectrometer. We firstly analyze the ocean wave scattering characteristics in different beams in order to find out the probable reason of modulation difference. Secondly, we construct the contribution look-up table of hydrodynamic modulation for extracting the valid modulation spectra. Thirdly, we propose the estimation method of modulation coefficient from the multi-beam data. Finally, the modulation spectra and modulation coefficient are imported into retrieval model to extract the directional ocean wave spectra in different beams. From this project, we propose the new way for retrieving the directional ocean wave spectra in different beams from spectrometer, which will be the power technological support of futher operational application.

中法海洋卫星（CFOSAT）将搭载全球第一颗星载波谱仪SWIM于2014年发射，届时可为全球化海洋研究提供丰富的海浪方向谱数据。波谱仪设置了5个海浪谱观测波束，但目前的海浪谱反演模型仅适用于10°波束，其它波束下由于海浪调制机理相对复杂，尚未确定有效的反演模型和方法。本项目拟通过查找表和多波束联合方式，基于现有反演模型，研究波谱仪不同波束下的海浪谱反演方法。首先通过比较不同波束下的海浪散射特性，来分析产生调制差异性的原因；其次，构建不同波束下调制谱中水动力调制贡献量查找表，用于提取不同波束下有效的调制谱。第三，针对波谱仪的多波束观测特点，提出多波束数据联合估计调制系数的方法。最后，将获取的不同波束下的调制谱和调制系数代入反演模型，反演出波谱仪多波束的海浪谱。通过这一项目的实施，将进一步发挥波谱仪多波束体制的优势，同时为数据后期的业务化应用提供有力的支撑。

中法海洋卫星（CFOSAT）波谱仪SWIM将于近年发射，目前的波谱仪海浪谱反演模型仅适用于10°波束，其它波束由于海浪调制机理相对复杂，尚未建立起有效反演模型和方法。本项目基于波谱仪的观测特点，从多波束、多卫星联合反演的角度，研究波谱仪不同波束下的海浪谱反演方法。首先，通过研究散射量随风速、风向、有效波高、波向等海面动力环境参数的变化趋势，揭示了波谱仪不同波束下的海面散射特性，建立了波谱仪的海面散射模型。其次，通过分析观测过程中入射角变化和水动力调制因素对传统波谱仪海浪谱遥感模型的影响，修正了不同波束下的传统海浪谱遥感模型。第三，针对波谱仪的多波束观测特点，提出了波谱仪多波束联合海浪方向谱反演方法。最后，基于波谱仪和SAR自身的优势和限制，提出了波谱仪和SAR联合反演海浪谱的方法。通过这一项目的实施，将进一步发挥波谱仪多波束体制的优势，同时为波谱仪数据后期的业务化应用提供有力的技术支撑。