Research On Processing Method Of Block Adjustment With Airborne InSAR

We can carry out block adjustment with InSAR to deal with airborne InSAR data which comes from large area under the conditions of sparse controlling, which makes us derive DEM of high quality in a very quick speed. Less control points will be needed if we do that, at the same time it is also an effective method to eliminate the differences in plane and height among multi-strip in the overlap. So that the efficiency of large scales SAR terrain mapping will be improved.In this paper, we have acquired the interferometric data by airborne InSAR system firstly, and the model with airborne InSAR was constructed by sensitivity equations of ground control points and tie points. Then we calculated interferometric geometry parameters and tie points’ geographic coordinates, so the differences in plane and height among multi-strip in the overlap area was eliminated. Finally, we got the DEM of the data.The main work of this paper is as below:(1) InSAR three-dimensional reconstruction model under geometric coordinate system was constructed, we also build sensitivity equations of baseline length, baseline angle, interferometric phase, initial slant range and Doppler center frequency to make this work easier, convenient and unified. Then we analyzed sensitivity of interferometric geometry parameters characteristics, which could be the foundation for error analysis.(2) A new airborne InSAR block adjustment was put up with, which was suitable for large area and multi-strip, linked all unit models. We related all unit models with InSAR points according to three-dimensional reconstruction model, and block adjustment model with InSAR on ground control points and tie points were built under the condition of sparse controlling. According to the least square principle, the interferometric geometry parameters and tie points’ geographic coordinates are calculated accurately, and finally high precision DEM data was directly generated by combined phase data and three-dimensional reconstruction model.(3) Experiments of block adjustment with InSAR were carried out, of which the data came from X-band interferometric data acquired by CASMSAR system. In this paper, stable and accurate interferometric geometry parameters and high precision DEM data were obtained by this way, and the effectiveness and practicability of this treatment method were verified.