Study On The Technology Of Scene Matching And Missile Location For Bistatic Missile-borne SAR

Precision-guidance of missile-borne SAR is a high-tech composite technology. Scene matching and missile location are key technology in terminal guidance of missile-borne SAR. Compared to traditional single base missile-borne SAR, there are several advantages of bistatic missile-borne SAR, such as high concealment, strong anti-jamming ability and small warhead weight. This thesis mainly studies the technology of scene matching and missile location in terminal guidance of bistatic missile-borne SAR. The main contents are as follows:1. A scene matching algorithm based on regional gray of bistatic SAR images for the gray-matching method is studied. Traditional scene matching algorithm based on gray correlation can’t match two images successfully because of the big distortion. Therefore, pretreatment is conducted for before scene matching SAR images. There are amounts of speckle noise in SAR images. Therefore, it is necessary to filter SAR images firstly according to Lee filter which is useful to remove speckle noise. Then adjust the resolution for the denoised images. Using normalized cross-correlation as similarity measure function, two-dimensional Fourier transform is adopted to improve the timeliness of scene matching algorithm. Simulation results prove the scene matching ability when there is an obviously difference between real-time image and reference image.2. A scene matching algorithm based on Wedgelet edge feature of bistatic SAR images is proposed. Traditional edge feature extraction algorithm is easily influenced by noise, the multi-scale analysis method Wedgelet which has good line singularity is adopted to extract edge feature of SAR images. In order to improve the timeliness of scene matching, scene matching algorithm is researched, which is from coarse-to-fine. NNPROD algorithm is used to match images in rough matching stage, while the Hausdorff distance is used as a similarity measure function in fine matching stage. Simulation results prove the matching ability of the proposed scene matching algorithm for SAR images.3. A missile location algorithm which regards Doppler frequency as a main train of thought for calculating missile location is proposed. On the basis of researching on the relationship between projectile and target, projectile location is introduced, which is realized by utilizing missile-borne SAR distance information, the parameter outputted by INS system and equivalent Doppler parameters. The formula of projectile location is derived and the locating process is given. Then the reasons which lead to positioning errors and the effect on missile location of delay error and height measurement error and equivalent Doppler estimation quantitatively to missile location are analyzed separately. Simulation results validate the performance of the proposed missile location algorithm.