Clouds from Visual Cameras - CERTIFIED
    Viking 1 - Jun 23, 1976 (Ls 85 MY 12) to Jul 25, 1980 (Ls 140 MY 14)
    Viking 2 - Aug 11, 1976 (Ls 107 MY 12) to Jul 19, 1978 (Ls 115 MY 13)

    Viking 1 data as an example of cloud occurrence. A Latitude vs time (Ls) plot of the detection of seven types of clouds within the martian atmosphere from images obtained with the Visual Imaging System.

    This data set consists of a catalog of clouds observed in Mariner 9 and Viking Orbiter images. The entire Mariner 9 and Viking Orbiter image data sets (approximately 7400 and over 50000 images, respectively) were examined at least twice, by two separate observers. Cloud occurrences were compiled by examining images for specific cloud morphologies, examining the same area at different times, utilizing limb images, and consulting photomosaics to determine the spatial relations of cloud obscurations. The data set contains details of the cloud occurrences and the images in which they were observed. Haze type clouds are most prominent during the mission.

    Useful Mission Documents

    The Data contained within the Viking orbiter imaging PDS cloud archive provide the location (latitude, longitude), time (Ls and time-of-sol), cloud type, and other quantitative aspects of the detected cloud occurrence and image conditions under which the cloud was detected.

    Retrieving the Data Volume

    Calibrated Data
    The data are presented in tabular ASCII form in the vo_clds.dat file. In addition, the vo_clds.dat file includes both Viking 1 and 2 data where the first 23 characters in each row indicate VO1 or VO2.

    Note: Mariner 9 (spanning Ls 293 MY 9 to Ls 98 MY 10), Viking 1 (spanning Ls 85- MY 12 to Ls 140 - MY 14) and Viking 2 (spanning Ls 107 - MY 12 to Ls 116 - MY 13) orbiter cloud data are contained in the same volume (vomr_0001). The file structure is the same for all 3 missions. Viking 1 and Viking 2 data are provided in a single file.