Continuously scanning time-correlated single-photon-counting single-pixel 3-D lidar

Long-range depth profiling of camouflaged targets using single-photon detection

“…15,17 For example, Shin et al 17 presented a reconstruction algorithm that restores multiple depths from an object behind a scattering media by solving a convex optimization problem accounting for the Poisson statistics and the sparsity of the data. However, this algorithm does not consider the possible spatial correlation of the hidden object and was only demonstrated using single-photon data obtained in indoor conditions over a range of 4 m. Alternatively, Henriksson et al 15 demonstrated a simple multisurface Gaussian fitting algorithm used in outdoor trials over tens of meters. This algorithm (i) filters the raw photon data to obtain a smaller number of peaks and (ii) uses a simple Gaussian fitting on the filtered histograms in order to obtain depth information.…”

“…This algorithm (i) filters the raw photon data to obtain a smaller number of peaks and (ii) uses a simple Gaussian fitting on the filtered histograms in order to obtain depth information. 15 Again this approach does not account for the spatial correlations of the hidden object and may present poor results when the measurement time is reduced. In the presence of multiple surfaces and at low acquisition times, a reduced number of photon counts is collected, resulting in no depth data or highly erroneous depth information being assigned to a significant number of pixels using pixelwise-based approaches.…”

“…Several experiments involving "seeing" behind or through various obscuring media have been previously performed using LiDAR systems. [13][14][15][16][17] References 13 and 14 present examples of 3-D laser radar imaging using a range-gated approach that can provide highresolution gated images using very few laser pulses. This approach requires high energy laser pulses (typically μJ) and does not give a full surface profile of the target, but instead provides a range-gated intensity image.…”

“…This approach requires high energy laser pulses (typically μJ) and does not give a full surface profile of the target, but instead provides a range-gated intensity image. Henriksson et al 15 presented a scanning TCSPC system that was successful in imaging targets through foliage at a distance of ∼300 m. The slow scan speed of the system meant that in the example demonstrated the acquisition time was 30 min for a 5 deg × 1 deg scene. Also, their algorithm for depth estimation did not take into account spatial correlations between neighboring pixels, resulting in many of the pixels providing no depth information due to a lack of returned photons.…”

Three-Dimensional Imaging via Time-Correlated Single-Photon Counting

“…TCSPC was mainly used in the detection of fluorescence lifetime in the early stage [4][5][6][7][8][9][10][11][12]. After that, TCSPC began to be used in the field of laser ranging [13][14][15][16][17][18] and gradually developed to the direction of laser long-distance 3D imaging based on time-of-flight (TOF) algorithm [19][20][21][22][23][24][25][26]. Recently, Li et al achieved the imaging of targets 45 kilometers away [27].…”