Abstract
Laser-based techniques have been applied to active imaging, ranging and terrain mapping. A review of currently available devices and techniques pertinent to laser-based sensing is presented. An important conclusion drawn is that the science has now matured sufficiently to make laser-based remote imaging a practical proposition. A major part of the thesis is directed towards the design and development of a prototype short range laser-based terrain mapping system. The pulsed gallium arsenide (GaAs) semiconductor-laser diode-based equipment described in the thesis is capable of determining terrain slopes at distances of up to 25m, The terrain mapper has been operated successfully, both in the laboratory and also during field trials. Results are presented which, although of a preliminary nature, indicate that the design aims have been achieved. An extensive investigation has been carried out into the performance of single heterojunction laser-diodes when operated with short duration (ie less than 10ns) current pulses. In this regime laser turn-on effects are found to dominate the laser's performance. Results of both theoretical and experimental studies are presented. Good agreement is found between theory and practice and the performance of these devices operating in this mode is now better understood.