An ocean current inversion accuracy analysis based on a Doppler spectrum model

BAO Qingliu; ZHANG Youguang; LIN Mingsen; GONG Peng

doi:10.1007/s13131-017-1115-y

基于海面多普勒谱模型的海浪反演精度分析

doi: 10.1007/s13131-017-1115-y

1.
国家卫星海洋应用中心, 国家海洋局空间海洋遥感与应用研究重点实验室, 北京 100081;清华大学地球科学中心, 北京 100084
2.
国家卫星海洋应用中心, 国家海洋局空间海洋遥感与应用研究重点实验室, 北京 100081
3.
清华大学地球科学中心, 北京 100084

基金项目: The National Natural Science Foundation of China under contract No. 41606202; the National Key Research and Development Program of China under contract No. 2016YFC1401002; the Open Fund of Key Laboratory of State Oceanic Administration (SOA) for Space Ocean Remote Sensing and Application under contract No. 201601001.

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- 收稿日期: 2016-04-05

An ocean current inversion accuracy analysis based on a Doppler spectrum model

1.
Key Laboratory of State Oceanic Administration for Space Ocean Remote Sensing and Application, National Satellite Ocean Application Service, State Oceanic Administration, Beijing 100081, China;Key Laboratory of Ministry of Education for Earth System Modeling, Department of Earth System Science, Tsinghua University, Beijing 100084, China
2.
Key Laboratory of State Oceanic Administration for Space Ocean Remote Sensing and Application, National Satellite Ocean Application Service, State Oceanic Administration, Beijing 100081, China
3.
Key Laboratory of Ministry of Education for Earth System Modeling, Department of Earth System Science, Tsinghua University, Beijing 100084, China

摘要

摘要: 微波遥感是海洋参数观测的一个重要手段。利用海面回波的多普勒信息或干涉相位信息进行洋流反演已经被应用于星载和机载雷达系统。然而，海面风浪和海洋表面流互相耦合，雷达回波的多普勒信息无法直接进行海洋表面流的反演。为了研究海洋表面流的测量精度，首先需要对海面多普谱模型的参数敏感度进行分析。本文建立了海面多普勒谱的数值仿真模型，并对模型结果进行了验证。对C波段不同风速和风向情况下的海面多普勒频移进行了仿真，并与经验的地球物理模型（CDOP）进行了比较，对合适的海浪谱函数和方向分布函数进行了筛选。分析了Ku波段的表面流速度估计误差对风速和风向误差的敏感度。结果表明，对于VV极化，当风速测量误差为2 m/s时，表面流速度估计误差可达0.15 m/s，当风向误差为20°时，侧风向的表面流速度估计误差可达0.3 m/s。
- 多普勒谱模型 /
- 海洋表面流 /
- 参数敏感度分析 /
- 测量误差
Abstract: Microwave remote sensing is one of the most useful methods for observing the ocean parameters. The Doppler frequency or interferometric phase of the radar echoes can be used for an ocean surface current speed retrieval, which is widely used in spaceborne and airborne radars. While the effect of the ocean currents and waves is interactional. It is impossible to retrieve the ocean surface current speed from Doppler frequency shift directly. In order to study the relationship between the ocean surface current speed and the Doppler frequency shift, a numerical ocean surface Doppler spectrum model is established and validated with a reference. The input parameters of ocean Doppler spectrum include an ocean wave elevation model, a directional distribution function, and wind speed and direction. The suitable ocean wave elevation spectrum and the directional distribution function are selected by comparing the ocean Doppler spectrum in C band with an empirical geophysical model function (CDOP). What is more, the error sensitivities of ocean surface current speed to the wind speed and direction are analyzed. All these simulations are in Ku band. The simulation results show that the ocean surface current speed error is sensitive to the wind speed and direction errors. With VV polarization, the ocean surface current speed error is about 0.15 m/s when the wind speed error is 2 m/s, and the ocean surface current speed error is smaller than 0.3 m/s when the wind direction error is within 20° in the cross wind direction.
- Doppler spectrum model /
- ocean surface current speed /
- parameter sensitivity analysis /
- measurement error

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参考文献(14)

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文章访问数: 1112
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PDF下载量: 1045
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基于海面多普勒谱模型的海浪反演精度分析

doi: 10.1007/s13131-017-1115-y

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An ocean current inversion accuracy analysis based on a Doppler spectrum model

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