Development of a coherent continuous wave carbon-dioxide laser radar imaging system

This dissertation deals with the theory and development of a range, Doppler and intensity imaging CO{dollar}sb2{dollar} laser radar breadboard. Several methods used to obtain the range and velocity of a target are described. Optical heterodyne detection and the technique of FM chirped pulse compression are reviewed. The relationship between the FM chirp bandwidth and the range resolution of the system is emphasized.; A novel intensity imaging CO{dollar}sb2{dollar} laser radar breadboard is then presented. The system utilitizes homodyne (one laser) detection without the use of any acousto-optic or electro-optic frequency shifting devices. A comprehensive description of the hardware involved is given and an actual image is presented.; Various CO{dollar}sb2{dollar} laser frequency modulation techniques are investigated. These methods involve modulating the radiation both external and internal to the laser cavity. In addition, the efficiency and feasibility of the modulation techniques are emphasized.; Finally, a three-frequency imaging system is introduced. The system sends two beams to the target and the return beams are simultaneously processed as first suggested in (1). The method used to generate the two transmitted beams and laser frequency modulation are described. The signal processing technique is then presented. The signal processing implements both radar pulse compression with the three-frequency heterodyne detection. The advantages of this laser radar system are investigated. Finally, imagery produced by this system is presented.