| FM/cw focal plane non-scanning imaging ladar is a three-dimensional imaging ladar with the characteristics of miniaturization, all-solid-state, high frame-rate and high rang accuracy. It has significant practical application in the commercial and military field, therefore, the ladar has become one of the focuses at home and abroad. Foreign countries have made a series of research progress, while the domestic is still in the initial research stage.This research project is the first exploration of 32×32 MSM self-mixing detector array for FM/cw non-scanning imaging ladar.The research project is to meet the development requirements of focal plane imaging ladar, analyse the research development of ARL and the problems they faced, We study and determine the key technology and implementation methods in ladar system, and make corresponding test and analysis from multiple perspectives for all parts of the performance, point out deficiencies, propose improvement methods.First of all, We study FM/cw ladar ranging theory, research and determine FM/cw non-scanning imaging ladar system, theoretical analysis of the impact of the detection range of radar systems, make theoretical analysis of the factor of the detection range, range resolution and ranging accuracy of radar systems, summarize three key technologies: high-power broadband laser emission system, 1.55μm FPA detector, reading out of 32-channel difference frequency signals.Then, we study the power, bandwidth, modulation rate, modulation depth of laser transmitter and their impacts on ladar performents. We test linear swept-frequency signal source, analyse the performance of ladar system from the standpoint of time-frequency relationship, SNR, harmonic noise components etc., and point out the shortcomings and put forward the improvement approach.Next, we study the requirements, the working principle and key technology of the FPA detector, design and make a 32×32-pixels MSM self-mixing detector, test the detector's responsivity under certain optical power, frequency response, mixing efficiency and filter characteristics to evaluate its performance, suggest improvements about material and structure of the detector.Finally, in order to realize the reading out of 32-channals different frequency signals, we design the method of time-division row mixing and column combination to form ladar image, This method simplifies the huge 1024-discriminator system. we design and make FPGA-based all-solid signal acquisition board, make use of QuartusⅡsoftware to simulate image signal acquisition process, and make qualitative and quantitative analysis of each signal processing modules. |
