## CHANGE LOG ## 1.0.0.0 - Initial version 1.1.0.0 - Upgraded to v1B00 of the IM. - Re-classified this dictionary as a Discipline Dictionary, instead of Mission Dictionary. - Renamed Orbital_Mission_Information to Orbital_Mission, Surface_Mission_Information to Surface_Mission 1.2.0.0 - Upgraded to v1D00 of the IM. - Add instrument_clock_start and allow helicopter use case. - Add instrument_start_time. This is instrument_clock_start converted to UTC. - Updated the definition for start_sol_number to allow a primary sol to be defined for mosaic products inplace of the actual starting sol value. 1.3.0.0 - Upgraded to v1E00 of the IM - Add year_number, year_number_reference attributes to Surface_Mission - Added Observation_Context class and attrbitues active_flight_computer, active_flight_imu under Mission_Information The Mission_Information class provides information about a mission. Describes the vehicle context at the time the observation was taken. The Orbital_Mission class provides information about an orbital mission. The Surface_Mission class provides information about a surface mission. 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. Identifies which of potentially several flight computers were used for this observation. Identifies which of potentially several inertial measurement units (IMUs) were used for this observation. The value of the clock returned by the instrument at the beginning of the observation. This may differ from the spacecraft clock due to several factors such as clock drift, or differences in definition of start time (for example, spacecraft clock might be when an image was commanded, but instrument clock might be after autoexpoure or autofocus processes), or differences in the time epoch between the instrument and the main spacecraft. This is instrument_clock_start converted to UTC The mission_phase_identifier attribute provides an identifier for a mission phase. The mission_phase_name identifies a time period within the mission. 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. Release_number is the number of a scheduled release of data from the provider to PDS. The first data release is typically Release 1. 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. solar_longitude is the solar longitude, as defined in the main PDS4 data dictionary. The spacecraft_clock_partition provides the clock partition active for the spacecraft_clock attribute. The spacecraft_clock_start is the value of the spacecraft clock at the beginning of the observation. The spacecraft_clock_stop is the value of the spacecraft clock at the end of the observation. spacecraft_clock_stop should only be used if there's also a spacecraft_clock_start value. start_local_mean_solar_time is the local mean solar time, as defined in the main PDS4 data dictionary. The start_local_mean_solar_time_sol element specifies the number of solar days elapsed since a reference day (e.g. the day on which a landing vehicle set down) for local mean solar time (LMST). Days are measured in rotations of the planet in question from midnight to midnight. The reference day is '0', as Landing day is Sol 0. If before Landing day, then value will be less than or equal to '0'and can be negative. start_local_true_solar_time is the local true solar time, as defined in the main PDS4 data dictionary. The start_local_true_solar_time_sol element specifies the number of solar days elapsed since a reference day (e.g. the day on which a landing vehicle set down) for local true solar time (LTST). Days are measured in rotations of the planet in question from midnight to midnight. The reference day is '0', as Landing day is Sol 0. If before Landing day, then value will be less than or equal to '0'and can be negative. The start_orbit_number attribute provides the first in a series of numbers that represent a set of orbital revolutions of one body around another. The start_sol_number is the number of the Mars day on which an observation began. Landing day is Sol 0. For multi-sol observations, such as mosaics, if start_sol_number is given but stop_sol_number is not, the start_sol_number may instead be interpreted as the primary, or most important, sol for this observation. stop_local_mean_solar_time is the local mean solar time, as defined in the main PDS4 data dictionary. The stop_local_mean_solar_time_sol element specifies the number of solar days elapsed since a reference day (e.g. the day on which a landing vehicle set down) for local mean solar time (LMST). Days are measured in rotations of the planet in question from midnight to midnight. The reference day is '0', as Landing day is Sol 0. If before Landing day, then value will be less than or equal to '0'and can be negative. The stop_local_mean_solar_time_sol should only be used if there's also a start_local_mean_solar_time_sol. stop_local_true_solar_time is the local true solar time, as defined in the main PDS4 data dictionary. The stop_local_true_solar_time_sol element specifies the number of solar days elapsed since a reference day (e.g. the day on which a landing vehicle set down) for local true solar time (LTST). Days are measured in rotations of the planet in question from midnight to midnight. The reference day is '0', as Landing day is Sol 0. If before Landing day, then value will be less than or equal to '0'and can be negative. The stop_local_true_solar_time_sol should only be used if there is also a start_local_true_solar_time_sol. The stop_orbit_number attribute provides the last in a series of numbers that represent s set of orbital revolutions of one body around another. The stop_sol_number is the number of the Mars day on which an observation ended. Landing day is Sol 0. The stop_sol_number should only be used if there's also a start_sol_number. Identifies the year of the observation, using the definition for year specified in year_number_reference. Identifies the system used to measure year_number. Current values include: Mars Year: Mars year as defined by Piqueaux et al (2015), extending Clancy et al (2000). Mars Year 1 started on April 11, 1955 at Ls (areocentric solar longitude) = 0, with subsequent years starting at Ls=0. Reference: https://doi.org/10.1016/j.icarus.2014.12.014