Imaging experiment: The Viking Mars orbiter

The general objectives of the Imaging Experiment on the Viking Orbiter are to aid the selection of Viking Lander sites, to map and monitor the chosen sites during lander operations, to aid in the selection of future landing sites, and to extend our knowledge of the planet. The imaging system consists of two identical vidicon cameras each attached to a 1026 mm T/8 telescope giving approximately 1° square field of view. From an altitude of 1500 km the picture elements will be approximately 24m apart. The vidicon is coupled with an image intensifier which provides increased sensitivity and permits electronic shuttering and image motion compensation. A vidicon readout time of 2.24 sec enables pictures to be taken in rapid sequence for contiguous coverage at high resolution. The camera differs from those previously flown to Mars by providing contiguous coverage at high resolution on a single orbital pass, by having sufficient sensitivity to use narrow band color filters at maximum resolution, and by having response in the ultraviolet. These capabilities will be utelized to supplement lander observations and to extend our knowledge particularly of volcanic, erosional, and atmospheric phenomena on Mars.