Determination of visible coordinates of the low-orbit space objects and their photometry by the CCD camera with the analogue output. Initial image processing

摘要

The number of artificial space objects in the low Earth orbit has been continuously increasing. That raises the requirements for the accuracy of measurement of their coordinates and for the precision of the prediction of their motion. The accuracy of the prediction can be improved if the actual current orientation of the non-spherical satellite is taken into account. In so doing, it becomes possible to directly determine the atmospheric density along the orbit. The problem solution is to regularly conduct the photometric surveillances of a large number of satellites and monitor the parameters of their rotation around the centre of mass. To do that, it is necessary to get and promptly process large video arrays, containing pictures of a satellite against the background stars. In the present paper, the method for the simultaneous measurement of coordinates and brightness of the low Earth orbit space objects against the background stars when they are tracked by telescope KT-50 with the mirror diameter of 50 cm and with video camera WAT-209H2 is considered. The problem of determination of the moments of exposures of images is examined in detail. The estimation of the accuracy of measuring both the apparent coordinates of stars and their photometry is given on the example of observation of the open star cluster. In the presented observations, the standard deviation of one position measured is 1", the accuracy of determination of the moment of exposure of images is better than 0.0001 s. The estimate of the standard deviation of one measurement of brightness is 0.1~m. Some examples of the results of surveillances of satellites are also presented in the paper.