In order to satisfy the application requirements of spaceborne three dimensional imaging lidar , a prototype of nonscanning multi-channel lidar based on receiver field of view segmentation was designed and developed. High repetition frequency micro-pulse lasers, optics fiber array and Geiger-mode APD, combination with time-correlated single photon counting technology, were adopted to achieve multi-channel detection. Ranging experiments were carried out outdoors. In low echo photon condition, target photon counting showed time correlated and noise photon counting were random. Detection probability and range precision versus threshold were described and range precision increased from 0.44 to 0.11 when threshold increased from 4 to 8.
In order to study the effect of structural parameters on the performance of fiber distance sensor with one normal single
mode fiber for illuminating and one inclined multimode fiber for receiving, a theoretical power-distance model is
established to describe the influence of the inclination fiber angle, the separation distance between the two fiber tips, the
offset distance between the two fiber tips and/or reflector angle on the modulation performance of the fiber distance
sensor. Numerical simulation results indicate that for the sensitivity of the sensor, it increases as the inclination fiber
angle increases, the separation distance decreases, the offset distance decreases and/or the reflector angle increases. For
the linear region, it increases as the separation distance increases, and/or the reflector angle decreases, however, it
change less obviously as the inclination fiber angle increases, and even remains unchanged as the offset distance is
changeable. For the dead zone, it decreases as the separation distance decreases, and/or the offset distance increases, and
the study would help the design of the inclined-fiber receiving distance sensor to the desired modulation performance.
In order to study the reflective intensity-modulated characteristics of a two fiber distance sensor with one normal single mode fiber for illuminating and one inclined multimode fiber for receiving, a rigorous theoretical mode using approximating the illumination light exiting the single mode fiber as having a Gaussian intensity profile is established to describe the influence of the inclination angle of receiving fiber on the intensity-modulated characteristics of the sensor. Numerical simulation results indicate that the distance sensitivity of the sensor gets higher as the inclination angle
increases and the sensitivity at an angle of 4° is nearly 7.65 times that of the sensitivity with 0°. Meanwhile, the blind
region, linear range and peak position also get shifted in comparison with the parallel fiber distance sensor, and the
performance of the fiber distance sensor can be optimized by adjusting the inclination angle of the receiving fiber.