| 摘要: |
| 通过对2次海上作业期间船载X波段测波雷达数据对比分析，发现雷达测得的有效波高值在一段时间内存在较大误差。在2017年12月6日10:00至17:00期间，相比于人工目测值，雷达测得的有效波高值持续偏低。通过分析现场的天气与环境状况，并且对比相同海况下未受降雨影响和受到降雨影响时不同时刻的二维海浪谱，发现该段时间内因有降雨且能见度低，导致雷达测量的海浪谱能量异常偏低，信噪比SNR异常偏低造成X波段雷达测得的有效波高值异常偏低。在2018年4月11日船只路过5号大浮标和4号大浮标期间，相比于浮标测值，雷达测得的有效波高值异常偏高。通过查看系统中最大流速设置，发现设定的最大流速值过高（为50 m/s）。这样滤波器的带宽过大，大量噪声可能会被当成海浪信号通过滤波器，导致雷达反演的信噪比SNR异常偏高，造成X波段雷达测得的有效波高值异常偏高。通过分析误差产生的原因，对雷达设置的调整以及雷达系统的进一步完善有一定的参考价值。 |
| 关键词: 物理海洋学 X波段雷达 有效波高 信噪比 误差分析 |
| DOI：10.3969/J.ISSN.2095-4972.2019.02.004 |
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| 基金项目:国家重点研发计划资助项目（2016YFC140260）；全球变化与海气相互作用专项资助项目（GASI-IPOVAI-02,GASI-IPOVAI-03） |
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| Error analysis of significant wave height of ship-borne X-band wave measuring radar |
| YIN Shu-guang,WU Wei-deng,JING Chun-sheng |
| (Third Institute of Oceanography, MNR, Xiamen 361005, China) |
| Abstract: |
| In this paper, with the comparison and analysis of the data of Ship-borne X-band wave measuring radar in two offshore operations, it is found that the high value of significant wave measured by the radar has a large error in a period of time. During the period from 10:00 to 17:00 on December 6, 2017, the value of significant wave height measured by the radar continued to be lower compared to the visual observational value. By analysing the weather and environmental conditions on the site and comparing the two-dimensional wave spectrum at different times under the same sea condition whether it was affected by the rainfall, we know that the rainfall and poor visibility occurred during this period had resulted in abnormally low wave spectrum energy on the radar. This would lead to a low SNR of radar inversion, further resulting in the small significant wave height measured by X-band radar. The radar measured significant wave height consistently higher than the buoy values when the vessel passed by the no. 5 and no. 4 buoys on April 11, 2018. Looked at the maximum flow rate setting in the system, it is found that the maximum flow rate set is over 50m/s. As a result, the bandwidth of the filter is too large and a great amount of noise as wave signals, might have passed through the filter resulting in a higher SNR of radar inversion and a higher value of significant wave height measured by X-band radar. It is valuable for both adjustment of radar setting and the further improvement of radar system by the error analysis. |
| Key words: physical oceanography X band radar significant wave height SNR error analysis |
