卫星散射计与海面平台所测的风场数据比较

基于南海北部海面PY30-1石油平台气象站测风仪2011年7月19日—2012年9月17日实测的风场数据,分别开展了对卫星搭载的ASCAT和HY-2散射计所测风场数据的比较研究,分析散射计的测风能力(选取的时空窗口为30 min和25 km)。结果表明:在南海北部海域,ASCAT 散射计所测风速和PY30-1石油平台气象站观测风速的均方根误差为2.53 m/s,风向偏差较大,均方根误差为47.87°;HY-2散射计所测风速和PY30-1石油平台气象站观测风速的均方根误差为3.41 m/s,风向的均方根误差为58.66°。分别按低、中和高风速的不同条件将ASCAT和HY-2散射计所测的风场数据与PY30-1石油平台气象站观测的风场数据加以比较可知,ASCAT和HY-2散射计都具有较好的测风能力, 前者所测风速与PY30-1石油平台气象站测风仪观测风速的均方根误差稍小于后者。在150 min和15 km的时空窗口下,ASCAT与HY-2散射计所测风速的均方根误差为0.72 m/s,风向的均方根误差为8.50°。

Comparison of seawind data between spaceborne scatterometer and platform measurements

The wind data from ASCAT were compared with those of HY-2 satellite, and their accuracy were verified with the data from oil platform in the northern South China Sea, which were collected from Jul. 19, 2011 to Sept. 17, 2012. The RMS (root-mean-square error) between ASCAT wind speed data and the platform-measured wind speed data is about 2.53 m/s. The RMS between ASCAT wind direction data and the platform-measured wind direction data is about 47.87°. The RMS between HY-2 wind speed data and the platform-measured wind speed data is about 3.41 m/s. The RMS between HY-2 wind direction data and the platform-measured wind direction data is about 58.66°(The temporal and spatial differences between the ASCAT and HY-2 date were limited to less that 30 min and 25 km). With the temporal and spatial differences between ASCAT and HY-2 date were limited to less than 150 min and 15 km, the RMS between ASCAT wind speed data and HY-2 wind speed data were also calculated in this paper, which were about 0.72 m/s. The RMS between ASCAT wind direction data and HY-2 wind direction data were about 8.50°. In conclusion, the measured data of ASCAT were a little better than those of HY-2, and it provide a basis for using seawind data of satellite in the northern South China Sea.