We built an underwater photon-counting wireless optical communication (WOC) system, proposed and verified a video transmission protocol for high bit error rate (BER) environment. At the transmitting terminal, each pixel of the video frame has a sequence number indicating its position, and the sequence number information and the pixel information are encapsulated into independent data frames. After the receiving terminal distinguishes between the sequence number frame and the pixel frame according to the flag bit, the pixel and the sequence number are correspondingly placed into the storage unit. The experimental results show that when the BER is more than 0.6, the contour of the video frame can still be recovered, which effectively solves the problem of pixel dislocation of video frame caused by bit error.
We synthesize the underwater communication channel characteristics, the Poisson random process of photon emission and detection, and use Monte Carlo simulation to establish a long-distance weak link underwater wireless optical communication (WOC) model. The effects of demodulation threshold, signal and noise optical power on system performance are studied, and the calculation formula of system bit error rate (BER) is derived. The experimental results show that the simulation results of the established system model are basically consistent with the experimental data. When the number of photons received in the bit interval is 25, the system BER is 1.05×10-4 .
We design a first-photon 3D Lidar system to solve the problem of reconstructing the target reflectivity and depth maps in low-light-level. The Monte Carlo method was used to simulate the photon counting model, mean value and gated filter algorithm for doubly stochastic Poisson point processes. The influence factors of reflectivity and depth imaging are light intensity, noise and scanning time, we simulated them and use gated filtering to suppress noise. The simulation results showed that the noise ratio, light intensity and scanning time all have impact on the reconstruct reflectivity and depth maps. if the light intensities and scanning time increase, noise ratio decrease, the image quality of target reflectivity and depth maps would improve. And the gated filtering can effectively suppress noise and improve the quality of target reflectivity and depth maps’ reconstruction. we simulate the system in order to verify the feasibility of the system design, provide reference and optimize to the design of system, save time and experimental costs.
Proc. SPIE. 10832, Fifth Conference on Frontiers in Optical Imaging Technology and Applications
KEYWORDS: Compressive imaging, 3D acquisition, 3D image reconstruction, Imaging systems, 3D modeling, Monte Carlo methods, Digital micromirror devices, Pulsed laser operation, Photon transport, 3D image processing
We propose a single-photon three-dimensional compressive imaging system based on TCSPC. The system uses compressive sensing instead of raster scanning to achieve high spatial resolution, and only two-dimensional reconstructions are required to image a three-dimensional scene. We also propose a system simulation model based on Monte Carlo, which is conduct with double poisson stochastic process model. In the simulation model, we studied the effects of imaging time, optical noise ratio, and gating algorithm on the imaging performance of the system. The results show that the single-photon compressive 3D imaging system based on TCSPC can image in 5 seconds. Noise gating can effectively improve the 3D imaging quality of the system. Our simulation provides a good choice of parameters for subsequent experiments. It has played a theoretical guiding role in the research and application of the actual three-dimensional imaging system.
In this paper, we propose a photon counting ghost imaging scheme based on time-correlated single photon counting, and based on this scheme, Monte Carlo simulation is conduct with doubly Poisson stochastic process model ,the feasibility of traditional ghost imaging and corresponding ghost imaging is verified in this simulation, the influencing factors such as the number of frame M and the number of pulse within a single digital micro-mirror device(DMD) period D is also analyzed in the simulation. The results shows that the corresponding ghost imaging algorithm can effectively reduce the calculation amount when the imaging quality is close between the two algorithms, and the number of frames M has a greater influence on image quality. The model can effectively verify the feasibility of system design and improve the efficiency of the experiment, saving experiment time and costs.
Proc. SPIE. 9795, Selected Papers of the Photoelectronic Technology Committee Conferences held June–July 2015
KEYWORDS: Visible radiation, Digital signal processing, Light emitting diodes, Modulation, Reliability, Telecommunications, Signal processing, Wireless communications, Data communications, Digital Light Processing
Based on the phenomenon that more and more cars use LED for lighting and the current rise of visible light communication technology, this paper proposes a vehicle real-time voice communication system with high reliability on the basis of visible light communication for verification. The paper introduces the design of digital audio collection and output module, On-Off Keying (OOK) modulation and demodulation, Reed-Solomon encoding and decoding module, array LEDs emission and the module of PIN receiving signals. The LED lamp frequency response, communication distance, error rate and other parameters are tested and calibrated. The digital audio real-time communication system’s receiving speed is 500Kbps when the communication distance is 3.9 meters.
The Long Slit Spectrograph is one of instruments onboard The World Space Observatory-Ultraviolet. Both the FUV (102-1700nm) and NUV (160-320nm) channels of LSS choose micro-channel plates (MCP) detector with anode readout in the focal plane. The MCP detectors with anode readout are typically used to provide photon counting imaging. According to the desired performance of LSS, the Vernier anode may be the optimum readout scheme. The Vernier anode is
famous for its high spatial resolution, however, the original decode algorithms of the Vernier anode is susceptible to wrongly decode, when the charge acquisition is not precise enough and the footprint size of charge cloud collected by Vernier anode is not small enough and eventually results in the deterioration of photon counting image. In this paper, the causes leading to image deterioration is
analyzed. The least-squares method was used to calculate the phase value to correct imaging distortions caused by charge measurement accuracy. The area ratio of each electrode covered by charge cloud is accurately calculated to improving the imaging results. The corrected algorithms are verified by experimental results and the results show that the correction methods can obviously improve the
quality of the original photon counting image.