Accuracy analysis of a dual camera system with an asymmetric photogrammetric configuration

This paper presents a dual camera system combining a wide field-of-view (FOV) surveillance camera and a pan-tilt-zoom (PTZ) camera with an asymmetric photogrammetric configuration, and focuses on the analysis of its attainable measurement accuracy. First, we discuss the geometric modeling of the asymmetric photogrammetric configuration and analyze the accuracy of measurement based on error propagation for different baseline lengths, different focal lengths, and different pan angles of the PTZ camera. Second, we performed a comprehensive accuracy analysis based on Monte Carlo simulation, which incorporated artificial noise into the input data. Third, we conducted actual experiments in indoor and outdoor environments to verify the theoretical and simulation results. We found that the baseline length between the dual cameras was the main factor influencing measurement accuracy. Increase of the PTZ camera focal length could improve the measurement accuracy, but this trend was not significant when its focal length was relatively long. The pan angle of the PTZ camera also influenced the measurement accuracy, but this influence was not significant at short ranges. From these discoveries, we present an optimum configuration of the dual camera system for better than 1 percent measurement accuracy of the range within a normal observation range (e.g., 60 m). This proposed dual camera system provides enhanced machine vision capabilities that can be used in various applications.