Measurement of Ocean Surface Currents by the CRL HF Ocean Surface Radar of FMCW Type. Part 2. Current Vector
Measurement of Ocean Surface Currents by the CRL HF Ocean Surface Radar of FMCW Type. Part 2. Current Vector
复制标题
FMCW型CRL高频海面雷达测量海面海流。
DOI：
10.1023/a:1007848804171
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发表时间：
1999
影响因子：
2.3
通讯作者：
Shinnchi Sakai
中科院分区：
文献类型：
--
作者：
A. Nadai;H. Kuroiwa;M. Mizutori;Shinnchi Sakai
通信研究实验室（CRL）一直在开发高频海洋表面雷达（HFOSR）。CRL双站点HFOSR系统可以澄清表面电流的分布，标称范围为50公里。本文提出了一种理论和实验分析的电流矢量的测量误差的CRL HFOSR系统，使用比较的瞬时电流矢量的HFOSR系统和海流计停泊在2米的深度，考虑到垂直电流剪切。理论分析表明，海流矢量测量误差的概率分布在空间尺度上形成同心椭圆，该同心椭圆与径向流速的均方根测量误差有关，而其纵横比仅与雷达波束的方位差有关。当方位差为直角时，电流矢量的测量误差最小。通过对CRL HFOSR系统和系泊海流计测量的瞬时海流矢量进行比较，发现雷达海流和海流计海流之间的差矢量分布与海流矢量的理论测量误差吻合得很好，当两个雷达波束之间的方位差在45 °和135 °之间时，差矢量长度的RMS约为10 cm s-1。因此，在这个方位角差范围内，双位置HFOSR系统的电流测量精度被认为小于10 cm s-1。理论分析适用于更宽的波束方位差范围。
The Communications Research Laboratory (CRL) has been developing high-frequency ocean surface radars (HFOSRs). The CRL dual-site HFOSR system can clarify the distribution of surface currents with a nominal range of 50 km. This paper presents a theoretical and experimental analysis of the measurement error of the current vector obtained by the CRL HFOSR system, using a comparison of instantaneous current vectors acquired by the HFOSR system and current meters moored at a depth of 2 m, taking account of the vertical current shear. The theoretical analysis shows that the probability distribution of the measurement error of the current vector forms concentric ellipses at a spatial scale that depends on the RMS measurement error of radial current velocity and with an aspect ratio that depends only on the azimuthal difference of the radar beams. When the azimuthal difference is a right angle, the measurement error of the current vector is at a minimum. A comparison between instantaneous current vectors measured by the CRL HFOSR system and moored current meters shows that the distribution of the difference vector between the radar current and the meter current agrees well with the theoretical measurement error of the current vector and that the RMS of difference vector length is about 10 cm s−1 while the azimuthal difference between two radar beams is between 45 and 135 degrees. The accuracy of current measurement by the dual-site HFOSR system is therefore considered to be less than 10 cm s−1 in this range of azimuthal difference. The theoretical analysis will be applicable for a wider range of the azimuthal difference of the radar beams.