Li Zhong Qiang

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Time-frequency analysis is combined with array processing to develop a direction of arrival (DOA) estimation method. The array data model is constructed in time-frequency domain by cross time-frequency distribution between the output of a reference sensor and those of two symmetric sub-arrays. Accordingly a subspace method is presented based on the average(More)
Dual-chamber pneumatic springs are widely in the vibration system for precision instruments, its controller design and structure optimization requires an accurate model. The top chamber model is an important and complicated part of the model for its volume variety caused by piston movement and rubber deformation. In order to obtain top chamber volume(More)
Space-based Space Target Detecting (SSTD) has great advantages than that of ground-based, so it is a necessary tendency to make efforts to develop this technology. This paper firstly analyses the effects on visible light imaging caused by the severely space environment, models the space-based image. After that, a new algorithm for target detecting and(More)
The satellite in ground-based infrared image often shows as a small target (often few pixels) in cloud background, which is difficult to be detected. This paper firstly analyses the background properties, models the background in infrared image, and puts foreword an adaptive background suppression algorithm based on Wiener method. After segmentation and(More)
An extended error model of n-port vector network analyzer(VNA) is proposed in this paper. With a new error term introduced at each unstimulated port, the imperfect switch effect is fully considered in the model. Especially, the model can be implemented for the VNA with 2n, even n+1 measurement channels under the no-leakage hypothesis. Via calibration(More)
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