The Applied Research Of Remote Sensing Digital Image Processing Technology In The Geological Mapping

Geological mapping is the process that defines, describes and explores the geological age,stratum, structure and mineral resources of one specific area. Its scale can be chosenaccording to the specific situation, among which1:500-1:50000are commonly used.Due to the terrible geological environment and bad weather, there exist investigationblind spots when traditional geological methods are used to do the field exploration of certainareas such as the Himalayas in China. During traditional geological mapping, the geologicalstaffs always select some special geological points. For example, when we use the1:200000scale to do the geological mapping, a geological point is selected every two square kilometersto observe. In that case, there will be blind spots, therefore, the accuracy of the geologicalmapping can’t be guaranteed. Filling a1:200000geological map in artificial way usually isextremely money-consuming, which takes a geological brigade consisting of two hundred tothree hundred people two years.Digital geological mapping, by means of the remote sensing digital image, makes acomprehensive and detailed observation on the whole area without any blind spots, whichhelps the geological workers to have a general knowledge of the entire geological mappingarea from the perspective of time and space and makes geological mapping results closer tothe reality.Recently, with the constant development of the remote sensing digital image processingtechnology applied in geological mapping, the geological workers are increasingly aware ofits importance and irreplaceability. Nowadays, the remote sensing digital image serves as thereference of the traditional geological mapping after some dealing methods. However, thereexist many problems in the process of using the remote sensing digital image processingtechnology to do the geological mapping. For example, during the remote sensing digitalimage preprocessing, there are some problems such as the loss of the pixel brightness values,the bluish of color composite image, contrast discomfort and not being conducive to visualinterpretation, leading to the distortion of image. Different image acquisition equipments ofthe various satellites have the same effect on the effective pixels in the images. For example,if the images of different brands tend to be strong, all the effective pixels will become strongaccordingly or vice verse.Currently, various methods of enhancing the remote sensing digital image contrast andcolor composite which are adopted can’t solve the problem of the loss of the pixel brightnessvalues after enhancement effectively. How to extract intactly the original digital informationcontained in the remote sensing digital image is the problem we are considering and solving. It has the direct bearing on the smooth development of the follow-up work, for example, theprincipal component analysis, wavelet transform and follow-up work, which will lay a solidbasis for the digital mapping.On the theoretical basis of nondestructive translational two-way contrast stretchingalgorithm, this study will try to come up with a modified algorithm minimizing the loss of thepixel brightness values, building a solid foundation for spread of the follow-up of remotesensing digital image. It is a worldwide problem to use remote sensing digital image to do thegeological mapping directly. We will choose the Mesozoic acidic intrusive rocks on theeastern coastal area of Zhejiang province as object of study, attempting to apply the remotesensing digital image processing technology to the geological mapping directly for the firsttime.