Long-range range-gated laser active imaging experiments

Abstract

Range-gated laser active imaging technology can apparently advance the imaging and identification performance for long-range dim target. In the atmospheric conditions, the range-gated imaging system performance is generally affected by many factors, such as wind, visibility, and so on. These influences are more apparent when the laser path is long. To study the long-range performance of the range-gated imaging system, we carried out a series of outfield experiments using an active imaging prototype system designed by ourselves. The laser active imaging prototype system includes a YAG laser, an intensified CCD (ICCD), several lenses for imaging, time control board, and image collecting system. To test the prototype system's performance and the influence factors, we chose many long range targets on the hills around our lab and carried out lots of experiments. To test the visibility influence on the system, we fixed the prototype system and chose a 3.7km telegraph pole as the target, and carried out imaging experiments in several days in different weathers. To test the gated performance, we chose four close targets all in one sight about 4.2km far away, and got each target image separately by adjusting the delay time. We get clear laser image of the beacon tower on the Great Wall in 10.9km far away, and the farthest target we got was the mountaintop distance of 21km. By analyzing the result, we get more knowledge about the ranging and imaging performance of the laser active imaging system, and the experiment data is helpful for system design and application in the future.