scholarly journals A Fast Detection Algorithm for the X-Ray Pulsar Signal

2017 ◽  
Vol 2017 ◽  
pp. 1-5 ◽  
Author(s):  
Hao Liang ◽  
Yafeng Zhan

The detection of the X-ray pulsar signal is important for the autonomous navigation system using X-ray pulsars. In the condition of short observation time and limited number of photons for detection, the noise does not obey the Gaussian distribution. This fact has been little considered extant. In this paper, the model of the X-ray pulsar signal is rebuilt as the nonhomogeneous Poisson distribution and, in the condition of a fixed false alarm rate, a fast detection algorithm based on maximizing the detection probability is proposed. Simulation results show the effectiveness of the proposed detection algorithm.

2014 ◽  
Vol 1044-1045 ◽  
pp. 818-824
Author(s):  
Bo Fan Yang ◽  
Rui Wang ◽  
Gang Wang ◽  
Li Zhao

Aiming at signal detection of radar target, concerning about on the basis of the influence of SNR on detection probability when false alarm probability is given based on N-P criterion, a kind of multi-sensor fusion detection based on SNR is put forward. It can improve system’s detection probability under the condition of required false alarm probability in the detection of low SNR signal. The simulation results show that the detection performance is significantly increased, no matter fusion detection system is composed of same sensors working in the same working point or different sensors.


2013 ◽  
Vol 765-767 ◽  
pp. 2242-2249
Author(s):  
Wen Wen Liu ◽  
Long Yuan ◽  
Zi Yang Liu ◽  
Tao Peng ◽  
Wen Bo Wang

We study on the energy detection algorithm of spectrum sensing. The performance of energy detection in spectrum sensing is measured by the false alarm probability and the missing detection probability. In a certain spectrum sharing environment, whether the energy detection algorithm can meet our requirement is depending on the length of observation time and the decision threshold selected. Several experiment results have shown that: when the decision threshold is too low, it will cause much more false alarm; when the decision threshold is too high, it will bring many missing detection. Therefore, it is crucial that choosing an optimal decision threshold according to the length of observation time. In this paper, the closed-form solution of the minimum-cost decision threshold is deduced by using the methodology of mathematical derivation, and a new criterion about selecting an optimal decision threshold is also proposed. At last, the conclusion is proved by simulation.


2013 ◽  
Vol 765-767 ◽  
pp. 2305-2308
Author(s):  
Shou Tao Lv ◽  
Ze Yang Dai ◽  
Jian Liu

In this paper, we propose a reliable spectrum sensing strategy based on multiple-antenna technique, called RSS-MAT, to combat the channel uncertainties. We derive the closed-form expressions of the false alarm probability and detection probability for RSS-MAT. Finally, we present simulation results to validate our performance analysis. As expected, the simulation results show that RSS-MAT outperforms the spectrum sensing strategy with single antenna.


2013 ◽  
Vol 333-335 ◽  
pp. 605-610
Author(s):  
Qi Wei Han ◽  
Ting Huang ◽  
Fei Qiang Chen ◽  
Jun Wei Nie ◽  
Fei Xue Wang

Interference monitoring and analysis for GNSS frequency bands plays an important role in construction and development of satellite navigation systems, which can promote interference source locating, and has much benefit for system construction and the development of anti-jamming equipments. Due to high satellite orbits, GNSS signals reached the ground are very weak and submerged below the thermal noise, which makes it vulnerable to interference. Interference sources for satellite navigation system require only a small transmission power; however, a significant interference effect can be obtained. Therefore, a high sensitivity is needed by interference monitoring for satellite navigation system. The interference judgment threshold is close to thermal noise power, which often causes a higher probability of false alarm. It is very important to reduce the probability of false alarm at the same time to ensure high sensitivity. In this paper, a high sensitivity (low missed detection probability) and low false alarm interference monitoring method is proposed, a dual decision threshold is designed, thus the probability of false alarm can be effectively reduced at the same time of identifying interference accurately. The experimental results demonstrated the effectiveness of the algorithm.


2012 ◽  
Vol 249-250 ◽  
pp. 231-240 ◽  
Author(s):  
Yi Di Wang ◽  
Jun Feng Sun ◽  
Wei Zheng

In order to improve the performance of interstellar autonomous navigation system, an interstellar autonomous navigation system using X-ray pulsar and stellar angle measurement is proposed. In this system, an X-ray detector, which is fixed on a gimbaled axis, is adopted. The detector can point at the different X-ray pulsars that are visible. By augmenting the clock error and the clock drift error as a component of the spacecraft state, the proposed system can correct the clock error of the atomic clock onboard. Furthermore, the observability of the corresponding system is investigated, and the result shows that the system is completely observable at most of time. The proposed system can provide an improved performance than traditional version of celestial navigation system (CNS). Through consequentially measure the difference pulsars, the proposed system can have a satisfactory performance. The proposed navigation system provides a prospective way for the realization of the deep space autonomous navigation system.


Robotica ◽  
2021 ◽  
pp. 1-26
Author(s):  
Meng-Yuan Chen ◽  
Yong-Jian Wu ◽  
Hongmei He

Abstract In this paper, we developed a new navigation system, called ATCM, which detects obstacles in a sliding window with an adaptive threshold clustering algorithm, classifies the detected obstacles with a decision tree, heuristically predicts potential collision and finds optimal path with a simplified Morphin algorithm. This system has the merits of optimal free-collision path, small memory size and less computing complexity, compared with the state of the arts in robot navigation. The modular design of 6-steps navigation provides a holistic methodology to implement and verify the performance of a robot’s navigation system. The experiments on simulation and a physical robot for the eight scenarios demonstrate that the robot can effectively and efficiently avoid potential collisions with any static or dynamic obstacles in its surrounding environment. Compared with the particle swarm optimisation, the dynamic window approach and the traditional Morphin algorithm for the autonomous navigation of a mobile robot in a static environment, ATCM achieved the shortest path with higher efficiency.


Author(s):  
Oscar Real-Moreno ◽  
Julio C. Rodriguez-Quinonez ◽  
Oleg Sergiyenko ◽  
Luis C. Basaca-Preciado ◽  
Daniel Hernandez-Balbuena ◽  
...  

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