Research On Passive Vision Aided Location Of Multiple Observers

Passive location is a key technology to target supervision, which is maturing in technology, deep in research and practical in facilities. Based on the definition of passive location, the system has the characteristic of good concealment, long distance performance and strong viability.Therefore, passive location has a specific significance in modern war, especially in future five-dimension battlefield of land, sea, air, sky, electricity.This paper proposed a practical method of multi-observer passive location based on computer vision. The location principle is that multiple cameras are aimed at the targets from different point of view and the images are used to achieve the location. The main achievements of this paper are as follows:Firstly, establish the model of camera and obtain the relationship between the pixel of target and the actual target. This paper used the simplest model of linear pinhole without considering the lens distortion because the charge coupled device has small distortion and high linearity to light response.Secondly, compute the internal and external parameters of cameras named as camera calibration. The internal parameters of cameras in this paper are foregone. As a result, the paper proposed a method of the external parameters calibration with the transformation from geocentric coordinates to right-angle coordinates and from NEU coordinates to right-angle coordinates. This method is simple and practical validated by experiment.Thirdly, compute the 3-D coordinates of solid targets, least square method is applied to estimate the 3-D coordinates of targets based on the calibrated cameras. This method is simple and fast in speed of operation.Fourthly, the hardware debugging of the location arithmetic and error analysis of experiment result. The experiment data are acquired by doing an experiment and the experiment result is computed using the location arithmetic. Based on the analysis, the experiment result illustrates that the location method is simple and applicable and has the advantage of high location precision, easy circuit designing, good concealment, strong ability of anti-jamming and low cost, which is suitable for practical applications, especially in military aspects.