CW range-resolved S-lidars: capabilities and limitations in range domain

Abstract

CW Range-resolved S-lidars (the S symbol comes from Scheimpflug) have gradually evolved into a new class of laser sensors for remote environmental monitoring and a potential alternative to traditional atmospheric lidars. Based on the biaxial optical scheme, they sense the environment by continuous-wave laser emitters, implement the triangular principle of range control and use position-sensitive photodetectors. Providing range-resolved monitoring of the environment, they are grounded on low-power CW lasers and advanced technologies of nanophotonics. We examined characteristic features of this class of lidars in the range domain, analyzed the potential width and limitations of their depth of field, as well as achievable boundaries of the non-dimensional factor characterizing the range resolution quality. Based on an analysis of requirements for sensor capabilities, we combined a number of parameters and introduced dimensionless quantities to simplify the characteristics of systems with many interdependent parameters and influence factors. We proposed a way to evaluate the range-domain efficiency of S-lidars based on the introduced criterion of range resolution quality. Applied to S-lidars with infinite and finite depth of field, their actual range-domain efficiency can be quantitatively characterized by using the introduced criterion and taking into account the instrumental limitations. All of this made it possible to develop generalized algorithms for evaluating range-domain related characteristics of CW range-resolved S-lidars, which are easily adapted to specific applications, and also significantly simplify the procedure for selecting instrument parameters to satisfy tactical requirements. The disclosure and generalization of specific features of S-lidars will expand applicability of this promising class of laser remote sensing devices.