Joint Eos / Modis And Balloons In The Chengdu Region Of Water Vapor Changes

MODIS is one of the most important detectors in series of satellites of the United States Earth observation System (EOS). It is nowadays a new generation optics remote sensing instrument of "image and spectrum unite as one" in the world, which represent the most advanced technique of carrying the satellites sensors and the remote sensing application.In the paper, the application, which includes MODIS data processing and MODIS data used in the water vapor reversion of Chengdu region, is studied. Firstly, MODIS data has been deal with special remote sensing software - ENVI. Through the projection and resizing operation of ENVI, the region including east longitude 103°~105° and north latitude 30°~32° is be selected. That means the region in the range of 2° striding east-west and south-north respectively. In order to obtain the precipitable water amounts of Chengdu region in the special time, just five channel data, which includes three data of water vapor absorbing (0.905,0.936 and 0.940 respectively) and two data of atmospheric window channels (0.865 and 1.24um respectively) have been selected and the channel rationing techniques have used as reversion method.Secondly, the detailed method using the L-band Secondary Windfinding Radar reversing the total content of atmosphere water vapor has been introduced. Because Radar 701 is outmoded gradually and Doppler radar has not been used widely, L wave band radar is playing an important role in the process of weather research and application.At the same time, the relation of atmosphere precipitable water amounts between measuring data and inversion value has been contrasted analyzed through combining the data provided by Chengdu Weather Bureau using Sounding Balloon measuring the water amounts with the data from MODIS inversion in the range of July, August and September, 2005. The results show that the calculation value is not consistent with measuring data completely. As for the data of July, the correlation is good. But it is not so perfect in August and September. The probable reason has also been proposed. One is the accuracy of measuring data is not so good. On the other hand, some parameters of inversion method should be corrected when used in the Chengdu region. It should be studied in the future.