Entity

Time filter

Source Type


Zhao P.,Beijing Institute of Technology | Zhang Y.,Beijing Institute of Technology | Wang K.,Beijing Institute of Technology | Qian W.,Key Laboratory of Space Object Measurement
IEEE Photonics Technology Letters | Year: 2016

This letter proposes a universal discrete-time recurrence (UDR) method to predict the response performance of Geiger-mode avalanche photodiodes (GM-APDs), where performance prediction for a free-running GM-APD is realized beyond the gate-limit assumption for the first time. The dead time effect is summarized as the discrete-time correlation law, and the afterpulsing is first incorporated in the performance prediction theory as an equivalent noise source. Simulations with appropriate parameters verified the high accuracy and low calculation-time requirements of the UDR method. © 1989-2012 IEEE.


Liu Y.,Science and Technology on Aerospace Flight Dynamic Laboratory | Liu Y.,China Aerospace Science and Technology Corporation | Zhao H.,Key Laboratory of Space Object Measurement | Cao J.-F.,Science and Technology on Aerospace Flight Dynamic Laboratory | And 5 more authors.
Journal of Beijing Institute of Technology (English Edition) | Year: 2015

Detection for systematical error is needed in navigation system for all instruments. A new method for systematical error real-time detection and estimation is proposed by theory of sparse optimization and UKF. In this method, a sparse optimization procedure is introduced for the systematical error detection at each filter time step. It has less risk of calibration delay and diversion of systematical error than traditional methods, which makes the error detection and the state estimation more accurate. According to the theory analysis and simulation results, the new method can solve state and systematical errors simultaneously by virtue of the effective error detection. Thus, the accuracy and reliability of navigation system with multi-sensor can be improved. © 2015 Beijing Institute of Technology.


Zhao P.,Beijing Institute of Technology | Zhao P.,Key Laboratory of Space Object Measurement | Zhang Y.,Beijing Institute of Technology | Zhang Y.,Key Laboratory of Space Object Measurement | And 2 more authors.
Guangxue Xuebao/Acta Optica Sinica | Year: 2015

In order to realize the echo online extraction for diffuse reflection laser ranging when echo photons are blocked by a large amount of noise photons, an echo online extraction method based on time correlation is proposed for diffuse reflection laser ranging system. Based on the characteristics of time correlation for diffuse reflection laser ranging data, the extraction problem is simplified into npoints searching problem. Next, the correctness of the extraction based on time correlation is verified. And the rules to select a propernare given further through the trade-off between search cost and extraction accuracy. Then, the evaluation criteria for short-time linearity and adjacent similarity are given in detail. Finally, Genetic algorithm is adopted to realize parallel search for buffer data and online data, decreasing the search time as well as increasing the extraction accuracy of ranging data. The echo extraction for Yunnan Station's experimental data show that the extraction method proposed has strong ability to extract echo signal from high noise background quickly, which provides a feasible way to realize the signal online extraction for diffuse reflection laser ranging. © 2015, Chinese Optical Society. All right reserved.


Zhao P.,Beijing Institute of Technology | Zhao P.,Key Laboratory of Space Object Measurement | Zhang Y.,Beijing Institute of Technology | Zhang Y.,Key Laboratory of Space Object Measurement | And 3 more authors.
Science China Technological Sciences | Year: 2015

The performance of detector limits the overall performance of laser ranging system. And the design of multi-hit detector is one of the feasible ways to promote the performance of detector. Currently, the segmentation method or the recursive method is commonly used to analyze the multi-hit detector model. To the best of our knowledge, this paper is the first to propose a combinatorial method to solve the multi-hit detector model from the perspective of discrete time. Then, universal formulas of total signal detection probability and the average count are deduced based on the Poisson distribution signal. Furthermore, analysis is made to figure out how the average count changes with different parameters, such as the dead time, gating time, rate intensity. As a result, for GM-APD, the multi-hit detector model is verified advantageously compared to the single-hit detector model in improving the average count theoretically. Meanwhile, a discrete step feature is presented when average count changes with dead time or the gating time, which is of great significance in gating time optimization. © 2015, Science China Press and Springer-Verlag Berlin Heidelberg.


Peng Z.,Beijing Institute of Technology | Peng Z.,Key Laboratory of Space Object Measurement | Yan Z.,Beijing Institute of Technology | Yan Z.,Key Laboratory of Space Object Measurement | And 2 more authors.
Optics Letters | Year: 2015

This Letter, for the first time, proposes the look-back-upon tree recurrence (LTR) method based on the Poisson statistics for discrete time to predict the performance of Geigermode avalanche photodiodes with a short dead time. The results of the proposed method correspond to the results of previous methods for diverse input fluxes. The LTR method possesses very low time and space complexity to allow for the real-time analysis of the Geiger-mode avalanche photodiodes' performance over the entire ranges of dead time and input diversity. © 2015 Optical Society of America.

Discover hidden collaborations