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To enhance the detection capability of weak targets and reduce the dependence of single-photon lidar target detection on the number of the time-correlated single-photon counting detection cycles, a convolutional neural network (CNN) based on the point cloud (CNN-PC) method is proposed in this paper for detecting targets in single-photon lidar. This approach utilizes the exceptional feature extraction capabilities offered by CNN. The CNN-PC method utilizes the feature extraction module of the trained CNN to simultaneously extract features from two-dimensional point cloud slices. Subsequently, it combines these features and feeds them into the classification module of the trained CNN for final target detection. By training the CNN using point cloud slices generated with a minimal number of detection cycles and employing a parallel structure to extract features from multiple point cloud slices, the CNN-PC method exhibits remarkable flexibility in adapting to varying numbers of detection cycles. Both simulation and experimental results demonstrate that the CNN-PC method outperforms the classical constant false alarm rate method in terms of the target detection probability at the same signal-to-noise ratio and in terms of the imaging rate and error rate at the same number of detection cycles. [ABSTRACT FROM AUTHOR]

To improve the locating accuracy of wireless sensor networks in passive localization, a positioning error correction (PEC) algorithm based on the estimation of offset circle center is proposed. In the PEC algorithm, the target position estimation, which is obtained by two-step locating method via the target range information extracted by the sensors, is taken as the initial value. In the polar coordinate system, a fixed offset along the polar direction is added to the range residual to form the offset circle. The position vector of the offset circle center is used to correct the initial target position estimation for obtaining a more accurate position estimation. Compared with the classical distributed passive localization algorithm, the PEC algorithm has strong adaptability and higher accuracy to sensor layout, and which has excellent performance under different sensor ranging accuracy and a good prospect of engineering application. [ABSTRACT FROM AUTHOR]