Laser Phase Rangefinders: Ways to Improve Accuracy

Abstract

   Scientific and technological progress in the field of geodetic and industrial measurements in terms of the use of laser rangefinders operating in ranges up to 5000 meters has led to a reduction in the error of such measuring instruments over the past ten years by two or more times. Such rapid development of high-precision rangefinder technologies has led to a significant revision of the requirements for their metrological support, as well as to the need to develop a new generation of length standards, the stock of metrological accuracy of which would provide an assessment of the metrological characteristics of all types of existing and promising length measuring instruments with a laser rangefinder. To solve this problem, the Institute’s staff conducted research within the framework of a number of thematic research and development works in terms of developing the appearance of a new generation of length standards operating in the range up to 5000 meters in an open atmosphere. Within the framework of this article, one of the developed models of a high-precision complex of measuring instruments for length and coordinate increments is considered, which is a serial high-precision laser phase light meter, modified by the institute’s staff in terms of the system for receiving and processing measuring signals. At the same time, in order to increase the accuracy of length measurements using the developed range finder layout, it is proposed to investigate ways to reduce the errors of the model components of the boundaries of its error. To ensure the smallest error in determining the hardware correction of the rangefinder layout, it is proposed to use funds from the state primary special standard of the unit of length. As promising ways to reduce the error in determining the phase difference of signals, it is proposed to use digital recording and signal processing devices that implement a method for calculating the phase difference of signals by mathematically processing the recorded data using a specially developed computational algorithm based on Fourier analysis. For the most accurate determination of the values of the pulse repetition frequency of signals and the values of the speed of light on the measured track, it is proposed to improve the means of determining these indicators. The use of the proposed methods to improve the accuracy of measuring the length of laser phase rangefinders allows you to provide the necessary margin of metrological accuracy.