Analysis and Optimization of Laser Ranging Techniques

The general criteria for the operational performance of laser ranging systems are considered in quantitative terms with emphasis being placed on the optimization of systems which must meet specific operational requirements. The entire range-determining process is discussed on a statistical basis and the target detection capabilities of a system are defined in terms of the relative probabilities of recording real and false targets. Within this analysis appears a detailed discussion of all contributing noise sources, these being reduced to a fundamental noise source for two specific systems which transmit at different frequencies. A comparison is then made between the relative power requirements of the two systems performing the same task. In the case of some pulsed gas lasers, the pulse duration is somewhat long, thus necessitating a compromise between range resolution and maximum range capability. The relationship between these parameters is discussed in detail. In addition, a technique is proposed whereby the resolution is varied as a function of target return. This technique employs a multiple pulse transmitter and automatically optimizes its resolution and range capabilities.