Television

Description

The TV camera consisted of a vidicon tube, 25- and 100-mm focal length lenses, shutter, filters, and iris mounted along an axis inclined approximately 16 deg to the central axis of the spacecraft. The camera was mounted under a mirror that could be moved in azimuth and elevation. Camera operation was totally dependent upon the receipt of the proper command structure from earth. Frame-by-frame coverage of the lunar surface was obtained over 360 deg in azimuth and from +40 deg above the plane normal to the camera Z axis to -65 deg below this plane. Both 600-line and 200-line modes of operation were used. The 200-line mode transmitted over an omindirectional antenna for the first 14 photos and scanned one frame every 61.8 sec. The remaining transmissions were of 600-line pictures over a directional antenna, and each frame was scanned every 3.6 sec. Each 200-line picture required 20 sec for a complete video transmission and utilized a bandwidth of 1.2 kHz. Each 600-line picture required nominally 1 sec to be read from the vidicon and required a 220-kHz bandwidth for transmission. The data transmissions were converted to a standard television signal for closed-cirsuit and public broadcast television. The television images were displayed on earth on a slow scan monitor coated with a long persistency phosphor. The persistency was selected to optimally match the nominal maximum frame rate. One frame of TV identification was received for each incoming TV frame and was displayed in real time at a rate compatible with the incoming image. These data were recorded on a video magnetic tape recorder. Over 10,000 pictures were taken by the Surveyor 1 camera before lunar sunset on June 14, 1966. Included were wide- and narrow-angle panoramas, focus-ranging surveys, photometric surveys, special area surveys, and celestial photography. The spacecraft responded to commands to activate the camera on July 7 and, by July 14, 1966, returned nearly another 1000 frames.