Two portable devices for the measurement of scatter of a laser beam and evaluation of the scattering materials' Vos function

摘要

Abstract: This paper describes the construction of two variants of a portable glare measurement system and the evaluation of their ability to determine the scattering effect that canopies have upon laser sources. The emphasis of this work was upon the development and demonstration of a portable glare measurement system based around a CCD camera system with high dynamic range. Two fundamental questions needed to be answered. Firstly, did the CCD have the required dynamic range and spatial resolution and, secondly, could it be made into a fully portable system. Demonstration portable glare measuring devices have been constructed using a high dynamic range Wright Instruments AT1 electronic camera and the results produced by these devices are compared to those taken from a large, laboratory-bound glare measurement system. It was found that, although performing to its specification, the camera alone did not have the required sensitivity to clearly distinguish the scatter function from the background noise while not being saturated by the central part of the scatter profile. However by also using neutral density filters to effectively enhance dynamic range, the camera was adequate for a scanning-type protable glare measurement system which could by fully portable. !1