3D NIR laser night vision based on gated range-intensity correlation imaging

Traditional NIR laser night vision systems can only obtain 2D images without target range information, and are also easily affected by fog, rain, snow and foreground/background. To solve the problems above, 3D laser night vision based on range-gated imaging has been developed. This paper reviews 3D range-gated imaging advances and focuses on 3D rangeintensity correlation imaging (GRICI) due to its better real time performance and higher spatial resolution. In GRICI systems, the typical illuminator is eye-invisible pulsed semiconductor laser, and the image sensor chooses gated ICCD or ICMOS with mega pixels and ns-scaled gate time. To realize 3D night vision, two overlapped gate images with trapezoidal or triangular range-intensity profiles are grasped by synchronizing the puled laser and the gated sensor. The collapsed range is reconstructed by the range-intensity correlation algorithm, and furthermore 2D and 3D images can both be obtained at the same frame rate. We have established 3D NIR night vision systems based on triangular GRICI, and the experimental results demonstrate that 3D images realize target extraction from background and through windows or smoke. The range resolution minimum is about less than 0.2m at the range of 1km in our GRICI-NV3000, and the range maximum of 3D imaging is about 5km in our GRICI-NV6000.