The ODY dictionary contains classes that describe aspects of the Mars Odyssey mission and related instruments. 2024-06-26 DVP. Initial version: classes and attributes for GRS. 2024-07-12 DVP. Merged in THEMIS-related changes from a branch. The description of the original: "2024-05-21 PG (pgeissler@usgs.gov) added THEMIS parameters, initial version" 2024-07-26 DVP. Added descriptions to attributes and renamed a GRS-specific class. 2024-07-29 TMH. Add in a missed update from PG (IMG) and a few definition fixes. The GRS_Observation_Information class is the container for GRS-related metadata elements. The ODY_Parameters class is the container for mission-specific metadata elements. The THEMIS_Image_Properties class contains attributes specific to THEMIS images. The THEMIS_Instrument_Attributes class contains attributes specific to the THEMIS instrument. The THEMIS_Observation_Context class contains attributes specific to THEMIS observations. 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. Numeric identifier for the sequence of commands sent to the Odyssey spacecraft which include this THEMIS observation. Abbreviated name of THEMIS camera used to collect this observation. The length of time the THEMIS VIS detector array is exposed per frame in an image. The version of THEMIS instrument flight software used to acquire the observation. Temperature of the THEMIS VIS camera focal plane array at the time of the observation. The gain value of the THEMIS IR camera; a multiplicative factor used in the analog to digital conversion. Description of the observation written by the THEMIS Mission Planner. The length of time required to collect all frames of all bands in the downlinked image. Numeric identifier for this observation within the onboard command sequence. The type of compression applied to the THEMIS VIS data onboard the spacecraft and removed before storage in the raw data file. The ratio of the size of the uncompressed data file to the compressed data file. The time between successive frames of a THEMIS VIS observation. Maximum brightness temperature value measured within the image. Minimum brightness temperature value measured within the image. The total number of scan lines missing from a THEMIS IR image when it was received at Earth. The mission_phase_name attribute provides the mission-defined name of a time period within the mission. The offset value of the THEMIS IR camera; the offset value multiplied by a constant voltage is added to the measured voltage in the analog to digital conversion. The orbit_number attribute identifies the orbit number when the observation was taken. The number of lines in a summed THEMIS IR image which were produced by averaging less than N lines of the original non-summed image, where N is the value of the spatial_summing keyword. Value of N/A used for spatial_summing=1. The product_type attribute identifies the type of data product. The product_version_id element identifies the version of an individual data product. release_number is the identifier of a scheduled release of ODY data from PDS. The first ODY data release has release_number "0001". The release_number for a given product is always the first release in which it appears, and does not change if the product is revised later. Status of onboard lossless compression algorithm applied before downlinking the THEMIS IR observation and removed before storage in the raw data file. The spacecraft_clock_start_count attribute provides the value of the spacecraft clock at the beginning of a time period of interest. The spacecraft_clock_stop_count attribute provides the value of the spacecraft clock at the end of a time period of interest. Odyssey spacecraft pitch orientation during this observation. Odyssey spacecraft roll orientation during this observation. Odyssey spacecraft yaw orientation during this observation. Description of the Odyssey spacecraft pointing mode during this observation; see ODY_ORIENT_POINTING.txt for definitions of valid modes. Onboard spatial average of NxN set of pixels, where N is the value of the keyword. A SPATIAL_SUMMING value equal to 1 indicates that no spatial averaging has been applied to the observation. Solar longitude (Ls) at the beginning of the observation period Solar longitude (Ls) at the end of the observation period Status of onboard algorithm which applies a temporal average of successive lines in an IR image. When enabled, THEMIS TDI averages 16 detector rows to equal one line in an IR image. The spacecraft clock value when the THEMIS instrument was commanded to acquire an observation. This can differ from the SPACECRAFT_CLOCK_START_COUNT (or the other START_TIME keywords) by as much as 4 seconds, depending on which bands are acquired in the observation.