Photoelectric space-object position measuring device

Claim 1

In a satellite-tracking telescope having sufficient focal length and having means for tracking the approximate orbital position of a space vehicle; means for determining the orbital position of a space vehicle in earth orbit by reference to known background stars whose apparent positions lie instantaneously near the space vehicle position, said means comprising a combined star and target-satellite-detecting assembly adapted to be mounted at the focal plane of the telescope and including a first, star-detector device adapted to be fixedly mounted to the bottom of the telescope frame for simultaneous movement therewith during the tracking thereby of a space vehicle in earth orbit, said first, star-detector device comprising a masking element of generally opaque design and having first, light-transmitting means adapted to transmit continuously the reflected light from the satellite being tracked and second, built-in means for sequentially intercepting and transmitting light originating from one or more background stars momentarily included in the same field of view as the space vehicle being tracked, and first photosensitive mans positioned to sequentially receive the said star light and generate signals at periodic intervals in response thereto and thereby provide an accurate indication of the position of the image of a selected background star on said masking element by averaging the elapsed time between the receipt of the first and last signals resulting from the sequential light transmission from said second, built-in means in a particular sequence thereof; said star and target-satellite-detecting assembly further including a second, target-satellite-detector device adapted to be rotatably mounted at the first, lighttransmitting means of said star-detector device and having second, light-transmitting means adapted to normally receive and transmit reflected light from, and representing the image of the target-satellite being tracked, and second, photosensitive means positioned to receive the reflected light transmitted by said second light-transmitting means and thereby operate a substantially continuous signal in response to the light received; said second, light-transmitting means further having second, built-in means for sequentially interrupting light reflected from said target-satellite on at least two time intervals and thereby intermittently breaking the signal being substantially continuously generated from said second, photosensitive means from the almost uninterrupted transmission of reflected light thereto, the time intervals between the sequential interruptions of transmitted light reflected from said target-satellite constituting an accurate measure of the distance and direction of the target-satellite image from the center of said second, target-satellite-detector device to thereby accurately locate the orbital position of the space vehicle relative to the position of the selected background star already located by the operation of said first, star-detector device.