Problem of determining highly accurate coordinates of artificial satellites by photographic methods

Problems which must be solved by determination of highly accurate positional observations of satellites include construction of an inertial system of coordinates for radio sources and its tie-in with the inertial system of coordinates based on optical observations of the stars. Solution of this problem requires the use of angular coordinates primarily of distant satellites, whose motion is little disturbed by the influence of higher harmonics of the terrestrial gravitational field and atmosphere. The problem of determining the angular coordinates of satellites by photographic methods with great precision includes a number of independent sections. The solution requires an increase in the focal length of the lenses used in satellite cameras. Futhermore, satellite observations must be performed with fast lenses, due to the low brightness of most satellites. Third, radiation receivers should be photographic plates capable of producing images 20-30 micrometers in diameter. Fourth, an accurate catalog of stellar positions is required for tie-in of the satellite position. Finally, computers must be used to process measurement data. The most promising method of increasing the accuracy of determining the angular positions of high altitude satellites by a factor of 2 to 3 is to use wide angle astrographs with focal length at least 2 m, lens diameter at least 40 cm, made using special satellite tracking cameras with exposure time of -1,000 s.