Studies On Landuse Dynamic Monitoring Technology Based On High Resolution SAR Data

With Ministry of Land and Resources of China building the national land use dynamic monitoring system,it is urgent to promote the country's 'One map' project,strengthen land use dynamic monitoring,emergency monitoring,verification after granting as well as law enforcement and supervision of illegal use of land.Furthermore,we should continue shortening the monitoring period,expanding the application areas and improving the monitoring effectiveness.At present,optical remote sensing images are the most common data source in traditional land use dynamic monitoring.However,in Southern China,especially in the Southwest regions of China,it is great difficult to obtain optical remote sensing images because of the natural conditions with humid,cloudy and rainy climates.In view of the situation of China which has vast land,complicated meteorological climate and underlying surface conditions,as well as an urgent need of quickly receiving monitoring data,Synthetic Aperture Radar(SAR)has obvious advantages due to the ability of penetrating clouds and fast imaging in All-time and All-weather on earth observation.China has been actively promoting the SAR application in land survey and monitoring,while because of their spatial resolution and other factors' constraints,the range of applications of SAR is greatly restricted.Since 2007,many high-resolution radar satellites have been successfully launched,such as RADARSAT-2 of Canada,TerraSAR-X of Germany,COSMO-SkyMed of Italian,ALOS-PALSAR of Japan and so on.They all have subsequent satellites launch plans with equal or higher resolution SAR sensors.These create the conditions for the practical application of land use remote sensing investigation and monitoring.The analysis and research on the key technologies and methods of SAR utilization in land use dynamic monitoring has gotten important scientific significance to the macro decision-making of monitoring land resources,and laid a solid foundation for the application of high-resolution radar data.The thesis is devoted to study the best effects of new high resolution polarimetric SAR data on typical objects' recognition in land use change monitoring.The analysis results based on RADARSAT-2 data are shown from the following aspects.1.The research on pretreatment method of high resolution SAR image(two main aspects are geometric correction and image filtering).For the lack of optical data in cloudy and rainy regions,an effective method for control points' selection is proposed in SAR image geometric correction.The potential of improving geometric rectification accuracy of RADARSAT-2 data with a corner reflector is analysed.The performance of several common speckle filter are compared,and a speckle filtering algorithms based on Mallat and a improved multichannel optimal weighted filtering method are proposed and programmed,which improve the visualization interpretation accuracy of SAR images.2.Polarization information enhancement has greatly improved the recognition ability for land monitoring,the thesis analyses the processing method of polarization data,concretely compares the effects of high resolution SAR data of different polarization modes on abilities of structure features and details' representation and change information recognition.At the same time,we compare the effect on multi-temporal SAR image enhancement and feature recognition.At last,we evaluate the result combined multi-polarization and multi-temporal SAR data through the test area.3.We introduce the idea of spectral features variation,fuse RADARSAT-2 data and optical image,analyze the new construction land's features in the fusion image,detect change information in land monitoring quickly,at last,we extract change information and evaluate accuracy.