Marine oil pollution is one of the most serious pollutants on the damage to the contemporary marine environment, with the characteristics of a wide range of proliferation, which is difficult to control and eliminate. As a result, marine oil pollution has caused huge economic losses. The remote sensing sensors can detect and record the spectral information of sea film and background seawater. Here we chose to use 250-resolution MODIS data in the area of Dalian Xingang, China where ill spill case was happened on April.4th, 2005. Based on the image pre-processing and enhanced image processing, the spectral features of different bands were analyzed. More obvious characteristics of the spectral range of film was obtained. The oil-water contrast was calculated to evaluate the feature of oil at different spectral band. The result indicates that IR band has the maximum value of reflective. So band ratio was used between 400nm and 800nm and the original radiance images were used between 800nm and 2130nm. In order to get the most obvious images of entropy windows of different sizes were tested in order to decide the optimum window. At last, a FCM fuzzy clustering method and image texture analysis was combined for the MODIS images of the oil spill area segmentation. At last, the oil spill zone was estimated, the results were satisfied.
Snow cover area is a very critical parameter for hydrologic cycle of the Earth. Furthermore, it will be a key factor for the effect of the climate change. An unbelievable situation in mapping snow cover is the existence of clouds. Clouds can easily be found in any image from satellite, because clouds are bright and white in the visible wavelengths. But it is not the case when there is snow or ice in the background. It is similar spectral appearance of snow and clouds. Many cloud decision methods are built on decision trees. The decision trees were designed based on empirical studies and simulations. In this paper a classification trees were used to build the decision tree. And then with a great deal repeating scenes coming from the same area the cloud pixel can be replaced by “its” real surface types, such as snow pixel or vegetation or water. The effect of the cloud can be distinguished in the short wave infrared. The results show that most cloud coverage being removed. A validation was carried out for all subsequent steps. It led to the removal of all remaining cloud cover. The results show that the decision tree method performed satisfied.
Satellite remote sensing imaging systems have provided a spatially and temporally continuous and effective method to
map the environmental and landscape changes over large areas on the earth's surface. In this study, multitemporal and
multisource satellite remote sensing images, including Landsat Multispectral Scanner (MSS), Thematic Mapper (TM),
Enhanced Thematic Mapper Plus (ETM+) and Advanced Spaceborne Thermal Emission and Reflection Radiometer
(ASTER), were used to study the environmental and landscape changes happened in Qinghai Lake area from 1973 to
2000. Change detection methods, such as image enhancement and false color composition, were used to highlight the
environmental and landscape changes, i.e. lake area shrinkage, desert expansion and cropland area variation. Results
showed that: lake area had shrunken by 275 km2 from 1973 to 2000; in contrast, the area of desert and cropland
increased by 287 km<sup>2</sup> and 310 km<sup>2</sup> during the same period, respectively. As a result, remarkable landscape changes have
happened: several sub-lakes have separated from the main lake in the east; the famous Bird Island in the west became a
peninsula connecting with the land. Analysis suggests that environmental and landscape changes of Qinghai Lake area
are mainly caused by natural factors and human activities.
Digital elevation model (DEM) is indispensable for many applications in earth sciences, and there are many kinds
of DEM generation methods, such as interpolation between contour lines from topographic maps, stereoscopy from
aerial photographs or satellite images, and interferometry from Synthetic Aperture Radar (SAR) data.
Due to long years of coal mining activities, topographic changes have happened to Fushun city, northeastern China.
In this study, different DEM generation methods of Advanced Spaceborne Thermal Emission and Reflection Radiometer
(ASTER) stereoscopy, ERS tandem Interferometry Synthetic Aperture Radar (InSAR), and Shuttle Radar Topography
Mission (SRTM) InSAR were discussed. Multi-temporal and multi-source DEM data, with different spatial resolutions
of 15 m, 40 m and 90 m respectively, were combined to study the topographic changes in the past 10 years caused by
open coal mining activities in western Fushun city. ERS InSAR DEM and SRTM DEM data are free of weather
conditions, but ASTER DEM quality may be affected by cloud coverage in some local areas.
Results from multi-source of DEM data, i.e. ERS InSAR, SRTM and ASTER DEM, show that obvious topographic
changes associated with coal mining activities have occurred in Fushun area. The depth of the famous West Open Coal
Mine is increasing in the past 10 years, and the maximum depth change is 140 m between 1996 and 2006. Meanwhile,
the elevation of three waste rocks piling fields increased more than 10 m due to the coal mining activities.