Visual Satellite Tube

a small telescope adapted for observations of artificial earth satellites. It is characterized by a relatively wide field of view (5°-10°) with a high field depth. Such telescopes are used to determine the celestial coordinates of satellites either directly with respect to stars whose coordinates are known (an observer notes the position of the satellite at a given moment relative to the stars) or with respect to divided circles, with which some types of visual satellite tubes are equipped (the observer fixes the time when the satellite passes through the center of the field of view and counts the circles.