| To extract the water covering information with the use of the remote sensingtechnology has been widely used in the area such as zoology environment monitoring,water resource investigate research, drought and flood disaster information gaining,disaster evaluation and post-disaster reconstruction and so on. The Poyang Lake is thelarge lake which has a unique natural wonders in china. By using the RS images toextract the water covering information makes the efficiently and dynamicallymonitoring of the water information come true. This research sets the Poyang Lake asthe research area, makes the MODIS RS images as the data source and uses the IDLwhich is object-oriented and the forth generation computer language and the ENVIsoftware which is powerful on the graphic processing, finally designs and completesthe synthetic method of several days and develops a online analysis and releasesystem which is quick on the water information calculating.This research chooses the EnviSAT ASAR to test the precision of the extractionresults of the MODIS data for the EnviSAT ASAR radar image has a strongpenetrating power which can resist the disturb from the mist and its spatial resolutionis150m. Based on the qualify analysis of the data, there are following results: we canextract the water covering information with the use of the mono temporal methodwhen there is little influence from the cloud and the result is approximated to the facts.In fact, the Poyang Lake is on its flood period during May to August and in this time,the weather is cloudy and rainy which makes the mono temporal unsatisfactory. Themethod of synthesize with several days could reduce the influence of the cloud andrain and makes the results perfect.Based on the develop and complete of the synthesize with several days, by usingthe C#+ENVI/IDL+JavaScript development mode, this paper designs andcompletes the analysis online and release system of the Poyang Lake water coveringinformation with the B/S architecture. This system is a platform which is on the basisof the user’s needs of different levels, integrates the remote sensing data, Googleinternet map, GIS technology and internet technology, and transfers the customizedPoyang Lake covering information via Web internet. The system realizes the internet based quasi-realtime extraction of the water covering information. |
