Selection Of Optimum Resolution Of Simulation Base Map From Space Remote Sensing Image

The thesis studied the optimum resolution of base map required by the simulation platform of space remote sensing image( "Platform") in Demonstration Center for Spaceborne Remote Sensing of China National Space Administration(CNSA). In the experiment, remote sensing image provided by GeoEye-1(2m), CBERS-02B(20m) and HJ-1B CCD1(30m) was selected as base map for simulation, and was then compared with real remote sensing image from target sensor Landsat7 ETM+. The quality of simulation image based on different base map was evaluated and analyzed to determine the optimum resolution.Three base maps were simulated according to chain simulation model and simulation principle of the Platform. The experiment mainly consisted of two steps: 1. simulation of radiation field on ground, 2. simulation of atmospheric radiation transmission. In the first step, remote sensing image from GeoEye-1(2m), CBERS-02B(20m) and HJ-1B CCD1(30m) was selected as data source. The image was first preprocessed(such as radiometric correction) and image of surface albedo of base map was obtained through inversion. Spectral match and simulation of imaging geometry were then carried out on the basis of imaging parameters of target sensor to complete the simulation of radiation field on ground. In the second step, surface albedo and atmospheric parameter of all base maps were input into MODTRAN – the atmospheric radiation transmission software, in order to simulate the influence of atmosphere on sensor imaging and obtain the image of entrance pupil radiance on the top of the atmosphere through forward modeling. At last, the image obtained from base maps was compared with real remote sensing image from target sensor Landsat7 ETM+. Given the cost and efficiency in practical application of remote sensing, the optimum resolution of base map was determined.The specific content and research results are as follows:(1) The simulation method based on remote sensing image in this thesis, compared with previous simulation method based on physical model, does not require any classification map and spectral library or any calculation of terrain’s elevation, so it is more accurate and efficient.(2) The thesis used the remote sensing image provided by four satellites as experimental data and took real satellite data as reference. The data was analyzed both as a whole and in different sample regions to determine the optimum resolution. Compared with most research methods based on single remote sensing data, the experimental results in the thesis are more real and accurate.(3) Landsat7 ETM+ was set as the target sensor to be simulated in the experiment. In the simulation of radiation field on ground, due to the inconsistency between the base map used in the experiment and the imaging parameters of target sensor, simulation of spectrum and imaging observation angle was performed against the image from three base maps by referring to the imaging parameters of target sensor. Therefore, the construction of radiation field on ground is more accurate.(4) To determine the optimum resolution, the thesis referred to real image of target sensor, adopted multiple evaluation indexes and analyzed the data in different sample regions. A vertical comparison was first conducted on quality difference of image from three base maps, and a horizontal comparison was then conducted on the proximity of image from three base maps to real remote sensing image. In addition, the image quality and the precautions in practical application of image were taken into account, leading to more accurate and practical research results.