南麂列岛海洋自然保护区海岸要素的IKONOS图像地学分析

海岛 ,特别是一些面积小的岛屿 ,处于复杂的环境中 ,具有陆地与海洋的多种尺度特征。 IKONOS卫星遥感图像是现有遥感信息中空间分辨率最高的卫星数据之一 ,因此是海岛详细探测、大比例尺遥感分析的重要信息源。南麂列岛作为国家级海洋自然保护区 ,素有“贝藻王国”之称 ,具有典型性和示范性。本文是利用 IKONOS卫星遥感图像研究南麂列岛岸线特征、人工构筑物与近海目标以及土地覆盖的初步成果。结果表明它对细小目标的探测具有很大的潜力。

IKONOS Image-based Analysis of Land Cover in Nanji Islands East China Sea

IKONOS satellite images are important information sources with one of the highest spatial resolutions as today's remote sensing application. The islands are complex objects with multi-dimensions and multi-scales, and there are special requirements for their detections. Nanji islands are typical representative areas of multi-kinds of biotic resources. Their detections for environment and resources are of a great potential by using IKONOS remote sensing methods. The paper shows some results on the detection of coastlines and their structures as well as some object features over sea from Nanji Islands by using IKONOS remote sensing images.Nanji Islands National Marine Nature Reserve was established in September 1990.It is located between 27°24′30″-27°30′00″N and 120°56′30″-121°08′30″E with an area of about 200 km2. The reserve is a marine ecosystem in nature, which mainly protects shellfish, algae and their ecological environment.There are 421 species of shellfish, 174 species of macro-benthic-algae, 459 species of macro-algae, 397 species of fishes, 257 species of crustaceans and 158 species of other marine creatures in the reserve.These kinds of biological resources exist mainly at the tidal zone areas. IKONOS imagery processing and extraction of key information are very important in achieving the coastline and inland features and their parameter estimations. The geometric correction of remote sensing images includes the selection of transfer schemes and correcting methods, achievement of the controlling points, the boundaries of output images, pixel sizes of images and re-samples of imagery grey scale. The transfer schemes are divided into both immediate and mediate methods. Mediate method is dealt with in the study. With regard to transfer method identification, the second order multinomial is chosen. More than 6 control points are required because there are 12 unknown data in the multinomial.Concerning IKONOS image fusion,there are quite a number of approaches for this purpose, for example HIS, essential component analysis, wavelet transfer and so on. Here HIS transfer combines with other methods. The fusion is carried out after image enhancement. The imagery fusion is perfected by using part of IKONOS's black-and- white band and multi-spectral images. Of them, multi-spectral images are chosen as the groups of 432 or 342 and 321 respectively, and then the excellent images with rich information are obtained. As for the extraction of coastline and island land covers, Envi software and supervised classification are applied to extract various informations in the study. Data on coastline, the construction of coastal zone, the natural and man-made objects and sea surface objects as well as land coverage and so on have been obtained based on information extraction from IKONOS images. The results indicate that it is of great potential to conduct large scale mapping of the islands and detect small marine objects. The developments of coastal and marine remote sensing applications for IKONOS and other new satellite images with high resolutions are very important. The problems and difficulty in applying IKONOS images are also discussed.