Data Set Information
DATA_SET_NAME MSL MARS ROVER ENV MONITORING STATION 5 MODRDR V1.0
DATA_SET_ID MSL-M-REMS-5-MODRDR-V1.0
NSSDC_DATA_SET_ID
DATA_SET_TERSE_DESCRIPTION
DATA_SET_DESCRIPTION Data Set Overview : The REMS instrument is a meteorological suite of sensors designed to provide measurements of air and ground temperatures, wind speed and direction, pressure, humidity and ultraviolet radiation. The REMS MODRDR data set contains processed REMS data converted to environmental magnitudes and corrected by factors having an influence in the measurements (such as rover heat sources, shadows and dust, among others). The corrections at this level have been applied either by models, by removing invalid data, or by selecting the most representative data (e.g. minimum of several sensors). In the case of the Wind Sensor, modelling includes not only corrections but also the estimation of the wind data itself. All the original data can be found in the previous processing levels. Data is a time ordered sequence of rows organized into a table, taken at a maximum resolution of one second. Each data product contains one sol worth of activity and has information from all sensors. Like in the ENVRDR there is a confidence level code for each sensor. This data set is the highest processing level produced by the REMS team. It should be of interest to anyone wanting to know Mars environmental information at the rover's location. Parameters : This data set includes the following information: - Wind sensor: horizontal and vertical wind speed, wind direction. - Ground Temperature Sensor: brightness temperature of thermopile A (band 8-14 um) and its estimated uncertainty. - Air Temperature Sensor: local air temperature around each boom and an estimated ambient temperature around the rover, calculated after a filtering of both local air temperatures. - Ultraviolet Sensor: ultraviolet radiation for each band and their estimated uncertainties. - Humidity Sensor: local relative humidity, volume mixing ratio, their estimated calibration uncertainties and the sensor operating temperature. - Pressure Sensor: pressure and its uncertainty. Pressure Sensor configuration (oscillator and low/high resolution mode). Sampling is at 1Hz maximum, with a baseline operation of 5 minutes every hour. Additional measurements can be taken on an on-demand basis beyond those hourly observations. For these additional measurements, and besides tactical day to day conditions and resources, there is a general pattern that covers selected hours of the day built by the scientific team during operations. That pattern is shifted from sol to sol to cover the whole 24 hours after a few sols. Additionally, extended measurements can also be triggered automatically if event mode is activated, in which case the REMS computer will decide or not to continue measuring after the regular cadence, by comparing the previous measurements with the expected trend. The objective is to capture any ongoing transitory atmospheric event. During the first 72 sols, for each 5 minute block, the following measurement strategy was used: Wind Sensor is switched off for 60 seconds, then it is switched on for 235 seconds, and then it is switched off again for the final 5 seconds. The rest of the sensors are switched on all the time. This strategy was based on results obtained during pre-flight testing. However, after evaluating flight data, it was determined that this strategy was not necessary, so from sol 73 onwards all sensors are switched on for each 5 minute block. From sol 793 onwards, a new measurement strategy for Humidity Sensor was introduced. It is called HS HRIM (Humidity Sensor High Resolution Interval Mode) and is only used on selected one-hour long observations. This new strategy intends to minimize heating of the Humidity Sensor, and consists of alternately switching on and off the sensor at periodic intervals. At the same time, Boom 2 is switched off, which means that there are no Wind Sensor and Air Temperature Sensor measurements. Processing : Processing starts with the generation of the REMS EDRs. The REMS EDR data products are generated by the MIPL (Multimission Image Processing Laboratory) at JPL, under the OPGS, using the telemetry processing software called MSLEdrGen. This software will convert the binary data received from telemetry to ASCII. EDRs will then be retrieved at Centro de Astrobiologia (INTA-CSIC) using the File Exchange Interface (FEI). EDR data products have a first automatic process using calibration data. The result of this is the TELRDR data set, which contains electrical magnitudes and thermal data. In parallel, using ancillary data provided by JPL (such as rover location, sun position) the ADRs (Ancillary Data Records) are generated. EDRs, TELRDRs, ADRs, and calibration data are processed together to obtain the ENVRDRs. The level of processing of the ENVRDRs includes environmental magnitudes with minimal corrections (mainly based on the degradation of the sensors). Finally, applying models developed by the REMS team and refining them with the confidence levels, the MODRDR data set is created. The processing to be applied to convert ENVRDR to MODRDR is the following: - Wind Sensor: application of an inverse model (based on calibration tests on a wind tunnel) to convert differential thermal conductances to wind speed and direction. Data too noisy, data taken with voltage out of range, and data taken with a gain not fully characterized is removed. - Ground Temperature Sensor: removed data from thermopiles B and C since their uncertainty is too high. Removed data not in calibration sequence or acquired when ASIC temperature is unstable. - Air Temperature Sensor: application of a model to get the local air temperature around each boom, by using the individual PT1000 sensors temperatures. Afterwards, a a single air temperature is calculated by filtering those two local air temperatures. - Ultraviolet Sensor: removed data measured when SZA (Solar Zenith Angle) is in a range which causes internal reflections inside the photodiodes. Data measured when the rover or the arm were moving is also removed. - Humidity Sensor: the median of the three humidity channels is calculated to get the local relative humidity. Volume Mixing Ratio is also calculated. - Pressure Sensor: data with drift correction applied. ADRs are used mainly to populate the confidence level codes found in MODRDRs. Some of those confidence levels take into account the projection of the shadows over the sensors using positions and locations contained in the ADRs. Finally, with a one to one time match between ENVRDR and MODRDR, the resulting data is integrated into a single table. Data : Each REMS MODRDR product in the data set is an ASCII table containing all sensors data. Each row contains an acquisition session, and columns contain the sensors values. Columns with related information are placed together, in the following order: time references (REMS clock, LMST and LTST), Wind Sensor, Ground Temperature Sensor, Air Temperature Sensor, Ultraviolet Sensor, Humidity Sensor and Pressure Sensor. REMS clock is synced with the spacecraft clock (SCLK) with a maximum deviation of 30 sg. LTST is given with respect to the rover position, in contrast with LTST given in REMS EDR labels and in other MSL data, which is given with respect to landing site. A confidence level code for each sensor is included. This code indicates the quality of the data by a string of zeroes and ones. Each character represents a factor by a '1' (good condition) or a '0' (bad condition). The higher the number of ones, the more reliable the measured magnitude is. The character 'X' may be present in some codes for factors whose value is not known at the moment of the data generation. A detailed description of the confidence levels can be found in the REMS RDR SIS. In addition to confidence level codes, some sensors include an estimation of the uncertainty in the provided data in another column. Columns are delimited by commas and are of fixed length. Rows are time ordered and are separated by a carriage return/line feed. Each table contains a sol of measurements. Data may be set to UNK if their value is not known and it will never be (such as saturation, or a specific sensor switched off during acquisition). They may also be set to NULL if their value is not known at the moment of the release of the data set, but it is expected to be known in a future release. If data from a sensor is set to UNK or NULL, its associated confidence level code will also be set to UNK or NULL. Ancillary Data : The ancillary data used in the generation of MODRDR data are laboratory calibration data and ADRs. Calibration data can be found in the CALIB directory. Calibration files are in plain ASCII text format. They are structured in a PDS label-like structure, with the form DATA : VALUE, each value taking up one line. A file per sensor is provided. The following information is contained in the ADRs: Solar azimuth and elevation Rover azimuth, elevation, altitude, pitch, yaw and roll Rover speed Masthead azimuth and elevation Rover temperatures UV sensor dust attenuation Coordinate System : This data set depends on several coordinate systems used in the MSL project. These are: - MSL_TOPO frame, fixed to landing site, is used to define rover position. - MSL_LOCAL_LEVEL, fixed to the rover, is used to define rover orientation (roll, pitch and yaw angles) - MSL_RSM_ZERO_AZ frame, fixed to the rover, is used to define rover remote sensor mast (RSM) azimuth. - MSL_RSM_ZERO_EL, fixed to the rover, is used to define rover remote sensor mast (RSM) elevation. - MSL_ROVER_MECH, fixed to the rover, is used to define Sun position angles (azimuth and elevation) Software : No software is provided in this data set. The RDR tables are simple ASCII files that can be displayed on UNIX, Macintosh, and PC platforms with common software.
DATA_SET_RELEASE_DATE 2019-12-05T00:00:00.000Z
START_TIME 2012-08-07T04:04:38.536Z
STOP_TIME 2019-07-31T07:11:24.136Z
MISSION_NAME MARS SCIENCE LABORATORY
MISSION_START_DATE 2003-10-01T12:00:00.000Z
MISSION_STOP_DATE N/A (ongoing)
TARGET_NAME MARS
TARGET_TYPE PLANET
INSTRUMENT_HOST_ID MSL
INSTRUMENT_NAME ROVER ENVIRONMENTAL MONITORING STATION
INSTRUMENT_ID REMS
INSTRUMENT_TYPE ENVIRONMENTAL STATION
NODE_NAME Planetary Atmospheres
ARCHIVE_STATUS LOCALLY ARCHIVED - ACCUMULATING
CONFIDENCE_LEVEL_NOTE Confidence Level Overview : Since MODRDRs are the last step in the REMS data processing pipeline, its reliability largely depends on that of all the data from previous processing steps. In addition, it also depends on the selection of parameters and modeling used by the REMS team. From sol 155 onwards, the Ultraviolet Sensor has been degraded beyond its operational functional requirements. This is caused by deposition of dust over it, which has made the attenuation of the signal to be greater than 10%. Wind Sensor data of boards 2 and 3 in boom 1 are not provided as they were damaged during landing. In addition, the following Wind Sensor boards in boom 2 are not operative starting on given sols: - Board 1, dice 1: since sol 854 - Board 2: since sol 1485 - Board 3: since sol 1491 - Board 1: since sol 1504 Review : The REMS RDRs were reviewed internally by the REMS team prior to release to the PDS. PDS also performed an external peer review of the REMS RDRs. Data Coverage and Quality : Each MODRDRs table provides sensors values measured during one sol. Data is dependent on REMS EDRs data products, pre-flight calibration data, SPICE data and ancillary data. Sensors switched off at the time of measurement are set to UNK. Data removed from ENVRDRs due to being unreliable are set to UNK in their corresponding sessions in the MODRDRs. Confidence level codes whose correspondent values are UNK or NULL are also set to UNK and NULL respectively. Wind data is preliminary and is pending further revision. Only horizontal speed and direction is given due to damage in wind boards. Degradation of the Ultraviolet Sensor from sol 155 onwards is flagged in its confidence level code as having an attenuation above 10%. Limitations : These data has been subjected to estimations and corrections. To check the original data, refer to ENVRDR and TELRDR records.
CITATION_DESCRIPTION Gomez-Elvira, J., Mars Science Laboratory Rover Environmental Monitoring Station RDR Data V1.0, MSL-M-REMS-5-MODRDR-V1.0, NASA Planetary Data System, 2013.
ABSTRACT_TEXT Data taken by the sensors of the Rover Environmental Monitoring Station (REMS) aboard the Mars Science Laboratory, in physical units, with corrections and modeling.
PRODUCER_FULL_NAME JAVIER GOMEZ-ELVIRA
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