为了获取准确的海冰信息,利用高空间分辨率和高时间分辨率数据相结合的方法来测算海冰面积,在假设TM海冰面积是比较准确的前提下,用TM海冰面积来订正MODIS和NOAA/AVHRR海冰面积,以提高这两种高时间分辨率遥感资料对海冰面积的判别精度。选取2003年2月5日的TM、MODIS和NOAA/AVHRR数据,在这3个图像上分别选择20个样本,然后进行了海冰面积的线性回归分析,得到的海冰面积提取订正模型。并分别以此两种模型为基础,对2002年12月8日至2003年2月26日和2005年2月1日至2月11日冬季渤海海冰面积进行修正,并将由MODIS和NOAA/AVHRR提取的海冰面积、用模型订正后和国家海洋环境预报中心给出的海冰面积做了详细的比较。结果表明:线性回归可以提高海冰信息的提取精度。此研究为海冰防灾减灾和海冰资源量估算提供依据。
At present, it is still worth discussing on how sea-ice area is surveyed precisely. The sea-ice area is surveyed with the combinative method of the high spatial resolution and the high temporal resolution data in this paper. MODIS and NOAA/AVHRR sea-ice areas are revised by TM sea-ice area under the premise of supposing TM as the relatively accurate data, which can enhance the distinction precision of these two kinds of high temporal resolution remote sensing data for sea-ice area. TM, MODIS and NOAA/AVHRR on February 5, 2003 are selected in this paper, and 20 samples are chosen on these three images separately, then the linear regression analysis of sea-ice area is carried out. The models of extraction and revising about sea-ice area are obtained. The sea-ice area in the Bohai Sea from December 8, 2002 to February 26, 2003 and from February 1, 2005 to February 11 is revised on the base of these two kinds of models respectively. And the sea-ice areas extracted by MODIS and NOAA/AVHRR, revised with the models and the sea-ice areas given by national marine environment forecast center are compared detailedly. The result shows that the linear regression can improve the accuracy of extraction. This research can provide a basis for prevention and reduction of disaster and resource estimation about sea-ice.