Xu Huaping

An algorithm for interferometric SAR data processing

In this paper, an algorithm of generating INSAR unwrapped phase image from SAR single-look complex images is presented. Besides the general processing technique, this article focuses on the methods of flat-earth phase removal, phase noise reduction and phase unwrapping. The availability is tested by the results of processing ERS-1/2 SAR images.

Performance evaluation of a 60 GHz ULA system for a non stationary source

The millimeter waves band is emerging as a possible solution to the bandwidth problem in wireless communications risen by the demand of wireless access to broadband internet by the users and an exponential increase in the shear number of the users. The present technologies use the currently available bandwidth to its almost theoretical efficiency but with even greater requirements for future wireless communication including 5G the current bandwidth may not be enough. The millimeter waves band has a huge bandwidth available to be used. Millimeter waves has its limitations for use in long range communication due to its higher propagation losses and blockage sensitivity but techniques like spatial multiplexing and beamforming may enable its use for both the long range and short range communications. The 60 GHz portion of the mmWave band not suitable for long range communications due to oxygen absorption is a good option for indoor communications and with the help of beamforming and phased arrays its a viable option for the indoor and short-range wireless communication satisfying the data rates of the future. In this paper we will also evaluate the performance of a Uniform Linear Array (ULA) based beamformed system for a non static source signal.

Analysis of phase preservation for bistatic SAR interferometrie processing based on multiple phase center sampling

Interferometry synthetic aperture radar (InSAR) is a remote sensing technique for obtaining high-quality digital elevation mode (DEM). Without temporal decorrelation, the efficiency and accuracy of bistatic and multistatic SAR are better than the single-pass interferometry. Multiple phase center (MPC) SAR increases the spatial sampling rate to overcome the contradiction of wide-swath observation and high azimuth resolution. In order to improve DEM coverage and accuracy, bistatic InSAR with MPC technique is proposed in our research, this interferometric data acquisition mode provides an effective approach for high-quality DEM generation. Phase-precision is well preserved, and simulation results verify the feasibility of bistatic MPC InSAR.

Extraction of building height based on modified double scattering model from single SAR image

Typical features in SAR image like the bright line cause by double scattering are important datum in building height extraction, especially for the extracting method form a single SAR imagery. Its accuracy will affect the extraction result. In this paper, against to the imprecise of double scattering model, we modified its geometrical relationship. By using this model, we proposed a method with the usage of pixel interpolation and image correlation to extract the height of rectangular and cylindrical buildings.

A new strategy of interferogram noise reduction for InSAR

This paper presents a new interferogram noise reduction strategy for InSAR. It emphasizes two aspects: Filtering along fringes using directionally dependent windows selected according to minimum phase differences; Filtering noise adaptively determinated by local noise level, which involves the parameter representing the phase statistics in complex domain. Simulation experiment demonstrated the effectiveness of this strategy by its capabilities in fringe preserving, residue reduction and adaptive noise filtering.

A simple implementation of multi-baseline INSAR

Multi-baseline INSAR is a kind of technology that obtains terrain height information using multiple SAR images, therefore, it has a better performance than single-baseline INSAR. There are primarily two methods to increase the accuracy of terrain height estimation. One increases the quality of the interferometric absolute phase image by utilizing several single-look complex images. The other decreases the errors of the terrain height estimation through iterative ways. Integrating the former method and noise-immune phase unwrapping method, this paper presents a realistic method to implement multi-baseline INSAR. This method mainly includes two steps; the first one is about how to obtain multi-baseline interferometric absolute phase image whereas the second one is the unwrapping mechanism. Then, through simulation, the achieved results not only demonstrate the validity and practicability of the method, but also prove that the performance of the multi-baseline INSAR is much better than single-baseline INSAR.