Feifeng Liu

Multiangle BSAR Imaging Based on BeiDou-2 Navigation Satellite System: Experiments and Preliminary Results

This paper analyzes the multiangle imaging results for bistatic synthetic aperture radar (BSAR) based on global navigation satellite systems (GNSS-BSAR). Due to the shortcoming of GNSS-BSAR images, a multiangle observation and data processing strategy based on BeiDou-2 navigation satellites was put forward to improve the quality of images and the value of system application. Twenty-six BSAR experiments were conducted and analyzed in different configurations. Furthermore, a region-based fusion algorithm using region-of-interest (ROI) segmentation was proposed to generate a high-quality fusion image. Based on the fusion image, typical targets such as water area, vegetation area, and artificial targets were compared and interpreted among single/multiple-angle images. The results reveal that the multiangle imaging method was a good technique to enhance image information, which might extend the applications of GNSS-BSAR.

3-dimensional target localization accuracy analysis based on radar network with aerial and ground-based nodes

Radar network has important application in many fields, such as small target detection etc, especially for the case with wide baseline. Until now, the research to the 3-dimensional (3D) target localization accuracy using radar network is still a research focus in the radar community. In this paper, further research to the radar network with aerial and ground-based nodes is carried out, and the analytical expression of 3D target localization accuracy is derived using the Cramer-Rao lower bound (CRLB). Based on the analytical formulae, impacts of the system topology on the target localization accuracy are investigated. Finally, numerical simulations verify the theoretical analysis of the results.

GNSS forward scatter radar detection: Signal processing and experiment

Passive radar detection systems based on Global Navigation Satellite System (GNSS) signals have the advantages of wide coverage, long detecting distance and good concealment. If effectively combined with the forward scatter radar (FSR) principle, it can be used to monitor an important area, which is of great significance to national defense security. This paper mainly focused on the analysis of signal Doppler characteristics of GNSS FSR. In addition, experimental results obtained with omnidirectional antennas and horn antennas are given.

Passive SAR with GNSS transmitters: Latest results and research progress

The passive Synthetic Aperture Radar with Global Navigation Satellite System (GNSS) employs GNSS satellites as transmitters and receivers mounted near the ground. Since GNSS constellations are designed for global, reliable and persistent operation, the most important advantage of such a system is the potential of permanent monitoring on the area which is overlooked by a fixed receiver. In the paper, an experimental prototype of GNSS-based SAR for the purpose of obtaining larger scene images as well as the development progress was introduced at the first place. And then a latest imaging experiment of GNSS-Based SAR for railway bridge was carried out and the image was obtained with high quality when it was firstly used for China Railway High-Speed (CRH) railway bridge imaging. The positive imaging result suggested that it is possible to achieve change information extraction using GNSS-based SAR for the further safety evaluation of CRH operation in China.