Research On The High Precision Dynamic Baseline For Complex Movement InSAR

Interferometric synthetic aperture radar (InSAR) imaging technology, the baselineaccuracy is one of the main factors affecting the elevation retrieval accuracy. Aircraftattitude and route changes due to aircraft motion platform instability, air and otherfactors, leading to equivalent baseline is time-varying in platform motion process.Conventional InSAR processing does not consider this problem, but the ues of a fixedbaseline elevation inversion parameters will inevitably lead to elevation retrievalaccuracy is greatly decreased. In non-ideal trajectory, the traditional RD algorithm can’tresolve the equivalent baseline changes,and the BP algorithm not only relative to thehigh precision, and offers the possibility to obtain accurate equivalent baseline. Let theBP algorithm to InSAR imaging,depth compensation method of moing baseline,provided technical support for the realization of high-precision elevation inversion. Themain work and innovations are as follows:1. Principle of InSAR measurements has been introduced in this thesis, accordingto the geometry of InSAR, analyzes the interferometric phase, target height andcorresponding relation between the baseline. Introduced the concept of dynamicbaseline, and analyzes the main factors affecting equivalent InSAR baseline.2. For rigid base, this thesis puts forward a kind of rigid dynamic baselinecompensation method based on BP. InSAR imaging is firstly analyzed, the traditionalinherent error of the RD algorithm, and analyzes the baseline time-varyingcircumstances defects of traditional RD algorithm, are introduced on the basis of BPalgorithm, is proposed based on BP’s rigid dynamic baseline compensation method.Analysis when compared to the baseline time-varying interference phase and ideal(reference) interference phase difference, phase compensation factor is obtained.Reference trajectory, the main antenna with motion compensation and auxiliary antennaphase compensation factors, make the main and auxiliary antennas trajectory consistent,eliminate the baseline of the time-varying, contain the ground information ofinterferometric phase, accurate height inversion formula available. Finally through thesimulation experiment, the contrast analysis of the ideal phase interference and baseline interferometric phase after the compensation, verify the effectiveness of the proposedcompensation method.3. Put forward a high precision dynamic baseline compensation method based onBP. Respectively, the reference trajectory for main, auxiliary antenna imaging,eliminates the baseline of degeneration. And through the analysis of interferometricphase and found that the compensation method not only eliminates the baseline whendegeneration, also removed the ground effect, reduces the difficulty of wrapped phasesolution. At last, through simulation experiments, under the condition of point target,compared the two methods of compensation precision.4. For the flexible dynamic baseline, puts forward a flexible dynamic baselinecompensation method based on BP. Combining with the characteristics of the flexibledynamic baseline, the first kind of baseline compensation method has failed, and thesecond kinds of compensation methods of ideas combined with flexible dynamicbaseline characteristics, puts forward a kind of flexible dynamic baseline compensationmethod based on BP. Under the flexible dynamic baseline, eliminate the baseline ofdegeneration, and removed the ground effect. Interference is verified through simulationexperiment, analyzes the ideal phase with the flexible dynamic baseline interferometricphase after the compensation, verify the effectiveness of the proposed compensationmethod.5. At the end of the thesis sums up the InSAR images at different stages in theprocess of handling the objective evaluation index, study the relevance, signal-to-noiseratio and residual nearly, the wrapped phase solution precision in different phases ofInSAR processing applications, and through comparing the above two kinds ofevaluation index precision compensation method.