Measurement of the location of projectile burst on water surface by dynamic image method and its error analysis

In order to measure the value of projectile points on the water surface accurately, a model of dynamic images measurement based on CCD camera is established. The function of the value of the surface point and its measuring error are analyzed by using the collected images information of the relative points taken by CCD camera secondarily. First, with the knowledge of spatial geometry, the azimuth and the elevation angles of three designated points on the target ship relative to the measuring ship are obtained. Then, combined with image coordinates of the specified points at t point, the relationship function of two sets of parameters between the image plane coordinate and angle information is presented by taking the constant model, so the azimuth and the elevation angles information of the projectile point is obtained. The function of three-dimensional projectile burst coordinates is presented by non-coplane intersection method. Finally, the coordinate's errors from the evaluation of the pinpoint of the image and the location measurement accuracy are discussed and the relationship is investigated. Experimental results indicate that the three-dimensional projectile burst coordinate's measuring error are 2.8, 4.9, 4.3 m, respectively, in the condition of the minimum intersection error, when the position accuracy is up to 0.05 m and the image pinpoint accuracy to be able to 0.5 pixel.