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 ENVRDR data set contains processed REMS data converted to environmental magnitudes. Only some of the external factors affecting the degradation of the sensors (such as dust in the Ground Temperature and Ultraviolet Sensors, among others) have been modeled. Ultraviolet Sensor data are corrected by the Solar Zenith Angle since otherwise they would not be useful. Other factors (such as rover heat sources, shadows and ASIC electronics noise, among others) have been flagged with a confidence level code to indicate the quality of the measurement. 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. This data set is the result of the second processing step in the calculation of the real environmental values measured by REMS. Data is converted from electrical magnitudes and temperatures to environmental magnitudes with only few corrections. Parameters : The information included in this data set for each sensor is the following: - Wind Sensor: longitudinal and transversal differential thermal conductance for each of the 3 boards in each boom. - Ground Temperature Sensor: brightness temperature of the 3  thermopiles, and their estimated systematic uncertainties. - Air Temperature Sensor: temperatures measured by each one of the  PT1000 sensors on each boom (unmodified from the TELRDRs), and their estimated uncertainties. - Ultraviolet Sensor: ultraviolet radiation for each band and their estimated uncertainties. - Humidity Sensor: relative humidity from each of the 3 channels, their estimated calibration uncertainties and the Humidity Sensor operating temperature. - Pressure Sensor: pressure from each of the 2 barocaps, 2 thermocaps temperatures and their estimated accuracy. 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 specific data used in the generation of ENVRDRs are: - Laboratory calibration data, which can be found in the CALIB  directory. - In-flight calibration data (of the Ground Temperature Sensor,  taken from EDRs). - ADRs. These Ancillary data are locations of the rover, the sun, and the masthead, and the estimated degradation factor of the UV sensor due to the dust. - Specific EDR data such as the ASIC temperature. ADRs are used mainly to populate the confidence level codes found in ENVRDRs. 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 TELRDR and ENVRDR, the resulting data is integrated into a single table. Data : Each REMS ENVRDR 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. Ground Temperature Sensor is corrected using in-flight calibration data (found in the TELRDR) and Ultraviolet Sensor responsivity is corrected depending on the Solar Zenith Angle and the estimation of the dust over the photodiodes. 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 ENVRDR 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.

Confidence Level Overview : ENVRDR data depend on the reliability of the calibration data and the ADRs, although extended calibration campaigns have been performed to verify them. In addition, several factors affecting the data quality are represented by the confidence level codes and the uncertainty data provides an estimation of that influence. 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  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%. 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 ENVRDRs 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. Saturated Wind Sensor data or those correspondent to damaged boards are set to UNK. Data from thermopiles B and C of the Ground Temperature Sensor are included but are too noisy to be considered useful. Confidence level codes whose correspondent values are UNK or NULL are also set to UNK and NULL respectively. 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 are not corrected from several factors such as external heat sources or shadows, so confidence level codes shall be revised carefully before using them.  Missing information from Wind Sensor in the boom 1 makes it difficult to estimate wind data when it is coming from behind the rover mast in the boom 2 direction.