ASTER 위성영상을 이용한 지형정보 추출 및 토지이용 변화검출

도시정보체계에서 토지이용 모형화를 위한 자료기반을 연구했다.

The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) on-board the NASA's Terra spacecraft provides along-track digital stereo image data at 15m resolution with a base-height ratio 0.6. It also provides fourteen multi-spectral image data from visible to thermal infrared. So it is possible to not only generate topographic information from stereo images but extract information about vegetation distribution, landcover, urban growth, urban environment and so on from multi-spectral images of ASTER data. Automated stereocorrelation procedure was implemented using the ENVI 4.1 software to derive DEMs with 15×15m in 43km long and 50 km wide area using the ASTER stereo images.

The accuracy of DEMs was analyzed in comparison with those which were obtained from digital topographic map of 1:25,000 scale. Results indicate that root-mean-square error (RMSE) in elevation between ±7 and ±20m could be achieved. Excluding the small areas which were covered with clouds, waters and building as the factors which make RMSE value exceed about 10m, the accuracy of DEMs showed RMSE of 5.789m. Landcovers of Gumi City area were respectively classified by applying supervised classification method to multi-spectral image data of Landsat TM, ETM^(+) and ASTER, and then changes of the area were detected by class.

It was seen that the built-up area was expanded by almost twice for the period of 19 years i.e. from 1985 to 2004. We expect that various scientific findings will be obtained by using the ASTER data.