NSSDCA ID: 1968-001A-01
Mission Name: Surveyor 7The TV camera consisted of a vidicon tube, 25- and 100-mm focal length lenses, shutters, polarizing filters, and iris mounted nearly vertically and surmounted by a mirror that could be adjusted by stepping motors to move in both azimuth and elevations. The polarizing filters served as anaylzers for the detection of measurements of the linearly polarized component of light scattered from the lunar surface. The frame-by-frame coverage of the lunar surface provided a 360-deg azimuth view and an elevation view from approximately +90 deg above the plane normal to the camrea A axis to -60 deg below this same plane. Both 600-line and 200-line modes of operation were used. The 200-line mode transmitted over an omnidirectional antenna and scanned one frame each 61.8 sec. A complete video transmission of each 200-line picture required 20 sec and utilized a bandwidth of 1.2 kHz. Most transmissions consisted of 600-line pictures, which were telemetered by a directional antenna. The frames were scanned each 3.6 sec. Each frame required nominally 1 sec to be read from the vidicon and utilized a 220-kHz bandwidth for transmission. The dynamic range and sensitivity of this camera were slightly less than those on the Surveyor 6 camera. Resolution and quality were excellent. The television images were displayed 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 that of the incoming image. These data were recorded on a video magnetic tape recorder and on 70-mm film. The camera transmitted 20,961 pictures during the first lunar day, January 10 to 22, 1968. From February 12 to 14, the camera was operated in the 200-line mode because of loss of horizontal sweep in the 600-line mode. During the second lunar day, 45 pictures were transmitted before loss of power caused suspension of camera operation.
Questions and comments about this experiment can be directed to: Dr. David R. Williams
Name | Role | Original Affiliation | |
---|---|---|---|
Mr. Raymond M. Batson | Other Investigator | US Geological Survey | |
Dr. Eugene M. Shoemaker | Principal Investigator | California Institute of Technology |