Study on Sea Ice Extraction and Area Correction Model Based on MODIS and GF Data

To gain correct sea ice data, high time resolution (MODIS) and high spatial resolution (GF-2) materials are combined to achieve wide-range high precision monitoring of sea ice area in Liaodong Bay. This article takes GF-2 sea ice area as the baseline, intercepts corresponding MODIS sea ice monitoring scope, establishes a sea ice area correction model, and conducts long time series' analysis of sea ice area change. Here's the result: spectral observation result shows that comparing with CH2 channel, spectral reflectance of the snow-covering sea ice, ice-water mixture, seawater and sea ice in CH1 are with a greater difference value and easier to distinguish. Comparing with the accuracy of 3 extraction methods of MODIS sea ice, the optimal method is CH1 single channel extraction. This paper takes the sea ice area extracted by GF-2 satellite as the benchmark data, then establishes a MODIS sea ice area correction model. The model's correlation coefficient is 0.96. The monitoring error after correction is reduced from 39% to 10%. Sea ice area change in long time sequence shows that the sea ice area of Liaodong Bay is in slight downtrend. The inter-annual variation is featured with 4 years' periodical change. In every winter, sea ice area is in unimodal change, and reaches the maximum value in about early Feb.