The Viking Lander mission dictionary contains classes and attributes specific to the Viking Lander mission and its instruments. Viking Lander version 1.0.0.0 PDS Build 1.21.0.0 Built with LDDTool -plJ -V xxxx PDS4_VIKINGLANDER_IngestLDD.xml xxxx is the model version, for example 1L00 2024-07-05 GEO/JGW Minor typo fixes. 2024-06-30 GEO/EAG Initial version with classes for general observation attributes and specific lander image attributes. This class provides a set of parameters that describe a Viking Lander image. The Observation_Information class provides information about a Viking Lander science observation. The Viking_Lander_Parameters class is a superclass containing all Viking Lander mission classes. This section contains the simpleTypes that provide more constraints than those at the base data type level. The simpleTypes defined here build on the base data types. This is another component of the common dictionary and therefore falls within the common namespace. Name for one of the twelve photodiode in a VL camera. The data transmission path from the cameras to Earth. The path could be recorded for later transmission or transmitted in realtime as the camera scanned. The data could be sent either by a UHF link to an orbiter or S-band link directly to Earth. A flag indicating whether a dust sequence was done with an image. One of six gain settings used in the conversion of photodiode voltage to DN. The hour and fraction hour within a sol that an observation began assuming a sol has 24 hours. The commanded center elevation of the scanning mirror used for an image. Zero elevation is generally pointed toward the horizon with negative values below and positive values above. Note that actual center elevation may be different for some non-nominal imaging modes. Sometimes vertical scans of data were lost in transmission to Earth or there were errors in the telemetry such that scans could not be extracted from the downlink. Missing_scans is the number of vertical lines that are missing from an image. A value of zero means no scans were lost. The mission_phase_name identifies a time period within the mission. Native time is the local lander time given as a sol number followed by hours, minutes, and seconds past local midnight on that sol. Sol 0 is day of landing. The Viking project used the format of sol number, hour, minute, and second for local lander time with times in a sol extending beyond 24 hours. This usage is different from the usage by recent Mars rover missions and PDS standard for local time. A short note that describes the observation. One of 32 offset settings used in the conversion of photodiode voltage to DN. The product_type_name identifies a group of data products within a collection that have some property in common, such as processing level, resolution, or instrument-specific setting. The temperature of the photosensor array (PSA) measured during the acquisition of an VL image. The VL camera could collect data without advancing the azimuth. This was called rescan, i.e., repeating the same vertical scan of data. This sometimes happened at the end of image and sometimes was commanded to repeat vertical scans. Start_rescan_sample is the sample value where rescan starts in an image. This value is zero if there was no rescan. The VL camera could collect data without advancing the azimuth. This was called rescan, i.e., repeating the same vertical scan of data. This sometimes happened at the end of image and sometimes was commanded to repeat vertical scans. Total_rescan_samples is the total number of rescan scans in an image. This value is zero if there was no rescan. The spacing in degrees between pixels within a scan line and between scan lines. The VL camera system has two rates of data collection - 16,000 or 250 bps. Beginning azimuth of an image scan. Values are in the camera-aligned camera coordinate system (CACCS). This zero azimuth for each camera generally points towards the other camera. Ending azimuth of an image scan. Values are in the camera-aligned camera coordinate system (CACCS). This zero azimuth for each camera generally points towards the other camera. Sol_number is the number of the Mars day on which an observation was acquired. Landing day is Sol 0. Start_sol_number is the number of the Mars day on which a multiple-day observation was begun. Landing day is Sol 0. Stop_sol_number is the number of the Mars day on which a multiple-day observation was ended. Landing day is Sol 0.