Research On High Power Emission Source And Range Extraction Of FM/CW Ladar

FM/CW ladar was invented in1995. It has developed into a low-cost、small-size、scannerless imaging ladar in recent years, which has great potentialin both commercial field and military field. FM/CW ladar includes two mainparts. One is the transmitter and the other one is the receiver. In the transmitterpart, how to achieve a high power modulated laser emission is one keytechnology. In the receiver part, range extraction of the target is another keytechnology. Based on the two key technologies, a15W high power emissionsource system is built and experimentally studied; meanwhile, simulation studyhas been made on range extraction of the target.In the part of high power emission source, the “seed light” opticalamplification scheme is adopted in this paper. A low power modulated laseroutput is obtained and then amplified by the optical amplifier to get a15W highpower output. To make the system smaller and enhance the ability of anti-jamming, a modularized semiconductor laser (EM650) is used as the light source.The corresponding “seed light” modulation system and the high power emissionsource system are built. A non-modularized semiconductor laser (CQF935/5624)is used to make a contrast test. A lot of static and dynamic modulationexperiments are conducted. By comparing the modulated signals anddemodulated signals in time domain and frequency domain respectively, themodulation performance of the system is evaluated. The modulation depth of thehigh power emission source system is tested and the modulation distortion istested and discussed.In the part of range extraction of the target, a simplified noise model ofFM/CW ladar according to the foreign document is used. Fast Fourier Transformmethod is used to extract the range of the target. The impact of noise on rangeextraction is studied. Four filtering algorithms are used in noise suppression, andthe performance of the four algorithms is evaluated respectively.