Comparison of the Spatial-Energy Profiles of Visibility Zones of Active-Pulse Vision Systems for Two Observation Methods

Abstract

By means of numerical simulation, a comparison was made of the features of the formation of spatialenergy profiles (SEP) of visibility zones (VZ) for the first and second methods of observation (MO), taking into account the energy of the noise threshold E_nt. It was confirmed for both MOs that the relation previously used in the literature, when the length of the VZ is uniquely determined by the sum of the durations of the illumination and strobing pulses (photodetector exposure), is valid provided that the maximum value of the signal contrast achieved within the VZ is close to unit. For the second MO, the transformation of the SEP at relatively short working distances into a short, convex asymmetric peak at half height, the maximum of which in the limiting case is shifted to the beginning of the VZ, has been studied in detail. This is explained by the predominant influence of the so-called spatial factor on the formation of SEP. Despite some spatial displacement of the SEP relative to each other for the first and second SN for the case when the duration of the illumination and strobing pulses are not equal, the maximum values of the recorded signals and their contrast, as well as the lengths of the visibility zones for both MOs, with typical parameters, in most cases practically coincide. For a particular case, when the duration of the illumination pulse is less than the duration of the strobe pulse, the SEPs of the VZ for the first and second MO were experimentally obtained, which confirm the results of the performed calculations.