REMS data sets

Data Set Overview

The REMS instrument is a meteorological package designed to provide measurements of air and ground temperatures, wind speed and direction, pressure, humidity and ultraviolet radiation.

This data set contains the raw unprocessed data stored in the REMS internal memory, as received from telemetry and formatted according to the REMS EDR SIS. It consists of a collection of tables that include the sensors readings as well as engineering data and instrument configurations parameters.

The information included in this data set needs to be combined using calibration and other ancillary information to get the physical magnitudes. The required ancillary information can be found in the RDR archive volumes.

Each data product in this data set contains one sol of activity time, in a time ordered fashion and taken at maximum resolution of one second.

This data set should be useful for anyone interested in knowing the actual sensors electrical readings and status before any processing is applied. The actual environmental magnitudes can be found in the REMS RDRs.

Parameters

Raw data consists of measurements from all REMS sensors which have been digitized from electrical data, such as voltages and resistances, to digital numbers or counts using a resolution of 12 bits. Engineering data and instrument configuration parameters are also included because some of them are required for data processing, although their primary function is monitoring and health assessment.

Data as stored in the REMS internal memory is a time ordered mixed sequence of entries of the following data types:

• Sensor Acquisition
• Engineering
• Humidity Sensor Regeneration Acquisition
• Humidity Sensor Regeneration Report
• Humidity Sensor Defrost Acquisition
• Humidity Sensor Defrost Report
• Ground Temperature Sensor Calibration
• Reset
• Sleep
• Event Entry
• Ground Temperature Sensor Gain Management
• Error

Sensors data are included in the Sensor Acquisition entries. Engineering entries contains some of their configuration modes. Additional instrument configuration parameters are stored in a separated area called the System Parameters. Detailed specification of the data contained in each type and in the System Parameters can be found in the REMS EDR SIS.

Sampling is taken at 1Hz maximum, for a baseline operation of 5 minutes every hour. Additional measurements can be taken on an on-demand basis beyond those hourly observations. These additional measurements can also be triggered automatically if event mode is active, in which case the REMS computer will decide whether to continue operating after the 5 minutes session by comparing the measurements taken and the expected trend. The objective is to capture any ongoing transitory atmospheric event.

During the first 72 sols, for each 5 minutes block, the wind sensor is set off for the first minute and the last 5 seconds, because it was believed it was causing noise to the rest of the sensors. After sol 73, the wind sensor is always on each time REMS is taking measurements.

Processing

The REMS EDR data products will be 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 and will generate a separate table for each of the data types mentioned above. This means that there will be a table for Sensor Acquisition entries, another for Engineering entries, and so on. Entries will be kept in time order.

System Parameters tables will be generated from data provided by the REMS team. In nominal operation mode, they don't need to be downloaded from the instrument, since they are set from earth by means of Spacecraft Commands and therefore their values are known. Only on special situations data may be obtained directly from the instrument.

Meta-data acquired from the telemetry data headers will be used to populate the PDS labels. If telemetry packets are missing during the initial downlink from the rover memory, partial data sets will be created. The data will be reprocessed after all data are received and a new version of the EDR (with a new version number) will be created. With the exception of NAIF provided ancillary data, all meta data stored in the label is acquired from the telemetry data stream.

Data

REMS EDRs included in this data set are a series of ASCII tables converted from the instrument's internal memory and accompanied with detached PDS labels. This makes it easy to load them in a spreadsheet program or in a database.

There is a table for each of the data types entries stored in the REMS memory. As for the System Parameters, instead of having one big table containing all of them, they are broken down into several tables for easier usage.

The tables for their corresponding REMS data types are:

ACQ	Sensor acquisition
ENG	Engineering
ERROR	Error
EVENT	Event Entry
GTS_CAL	GT sensor calibration
GTS_GAIN	GT sensor gain management
HS_DEF_ACQ	Humidity sensor defrost acquisition
HS_DEF_REPORT	Humidity sensor defrost report
HS_REG_ACQ	Humidity sensor regen acq
HS_REG_REPORT	Humidity sensor regen report
RESET	Reset
SLEEP	Sleep

The System Parameters tables are:

SP_ASICS	ASIC configuration
SP_EVENTS	Event mode configuration
SP_GTS	Ground temperature sensor configuration
SP_HS_DEF_REG	Humidity Sensor defrost configuration
SP_HS_PS	Humidity and Pressure sensors configuration
SP_MIS	Miscellaneous configuration
SP_WS	Wind sensor configuration

Each table contains one sol of activity time and data is time ordered, with a timestamp reflecting the beginning of each data acquisition. System Parameters are stored for each of the acquisition sessions, since their status is necessary to process acquisition data.

One data product is created for each table, with the exception of Humidity Sensor regeneration acquisition and report one side, which are on the same data product, and Humidity Sensor Defrost Acquisition and Report on the other side, which are also on the same data product.

Ancillary Data

Ancillary data required to process EDRs and subsequent RDRs to get environmental magnitudes are:

• Laboratory calibration data
• Solar azimuth an elevation
• Rover azimuth, elevation, altitude, pitch, yaw and roll
• Rover speed
• Masthead azimuth and elevation
• Temperature closest to power supply
• Deck temperature
• Front-right side temperature
• UV sensor dust attenuation

Although some of these data can be obtained from external sources, all of them are included in the RDR archive volumes, either as RDRs or as separate files.

Software

No software is provided in this data set. The EDR tables are simple ASCII files that can be displayed on UNIX, Macintosh, and PC platforms with common software.

Confidence Level Overview

The data presented in the REMS EDR is intended to be the least processed, most primitive data set released for REMS. Data presented here are an accurate representation of REMS data as received from the rover.

Data Coverage and Quality

Data reported are the minimally processed data received from the orbiter during nominal REMS operations. All data received is reformatted into one of the EDR data types. Data are by definition of good quality, as damaged telemetry packets are sequestered upon receipt from the spacecraft. We do not expect to receive many (if any) damaged data packets.

Limitations

The major limitation of this data set is that this is level 0, minimally processed data. The data are received from the spacecraft telemetry and ingested into a database. If gaps exist in the telemetry, data are lost.

Data Set Overview

The REMS instrument is a meteorological package designed to provide measurements of air and ground temperatures, wind speed and direction, pressure, humidity and ultraviolet radiation.

The REMS TELRDR data set contains processed REMS data where the counts given by the analog/digital converters from the instrument sensors have been converted to their corresponding thermal and electrical values, taking into account calibration information, gains and other possible electrical altering factors (such as the ASIC temperature). All these data can be found in the REMS EDR data set with the exception of calibration information. Whenever it is possible, temperatures instead of resistances are given, since conversion between them is straightforward. This implies that air temperatures from the Air Temperature Sensor are already present at this level.

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 represents the first intermediate processing step to calculate environmental magnitudes. No external models or corrections have been applied.

Parameters

The information included for each sensor is the following:

• Wind Sensor: convective powers and hot temperatures from the 12 transducers for each boom. Cold temperatures from the 3 boards in each boom where the transducers are allocated.
• Ground Temperature Sensor: temperatures and voltages from the 3 thermophiles. Calibration plate temperature.
• Air Temperature Sensor: temperatures measured by each one of the PT1000 sensors on each boom. There is no sensor at the base of the rod at boom 1, so for that boom the third temperature is the mean of the three thermopiles temperatures.
• Ultraviolet Sensor: photodiodes output currents and sensor operating temperature.
• Humidity Sensor: sensor capacities for each of the 8 channels.
• Pressure Sensor: sensor capacities for each of the 8 channels.

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.

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.

In the process to convert EDRs to TELRDR, the procedure to calculate the electrical magnitudes from counts varies from sensor to sensor. These counts are the result of a digitization from an Analog/Digital Converter, so the reverse process is done using data obtained during the calibration of the instrument. These data are included in the CALIB directory.

Three of the sensors (Wind Sensor, Ground Temperature Sensor and the Air Temperature Sensor) are handled through an ASIC (Application-Specific Integrated Circuit), and are affected by its temperature and power conditions. These ASIC values and their effects are included in the processing in addition to the digital-analogical conversion. ASIC information is also included in the EDRs.

Finally, with a one to one time match between EDRs and TELRDRs, the resulting data is integrated into a single table.

Data

Each REMS TELRDR product in the data set is an ASCII table containing all sensors data, accompanied by a detached PDS label. Each row contains an acquisition session, while columns contain the sensors values. This makes it easy to load the data products in a spreadsheet program or in a database.

Columns with related information are placed together, in the following order: the timestamp and the corresponding LMST in which the measurements where taken, Wind Sensor, Ground Temperature Sensor, Air Temperature Sensor, Ultraviolet Sensor, Humidity Sensor and Pressure Sensor.

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.

Ancillary Data

The ancillary data used in the generation of this data set is laboratory calibration data, all of which 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 ancillary data are needed to generate higher level data and to estimate its quality:

Laboratory calibration data Solar azimuth and elevation Rover azimuth, elevation, altitude, pitch, yaw and roll Rover speed Masthead azimuth and elevation Rover temperatures UV sensor dust attenuation

These data can be found as part of the REMS ADR records.

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

The data presented in this data set has been processed by applying laboratory calibration data and formulas derived from the REMS electronic design. Accuracy of these data is the correspondent to that one of the calibration process, although extensive tests in representative conditions have been done to ensure its reliability. Wind Sensor data of boards 2 and 3 in boom 1 are not provided as they were damaged during landing.

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

Data reported are processed data derived from raw data received during nominal REMS operations. Each TELRDRs table provides sensors values measured during one sol, which are dependent of pre-flight calibration 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. When the Pressure Sensor is acquiring in high resolution mode, the channels not in use are set to UNK.

Limitations

The major limitation of this data set is that most of the data is at the electrical level.

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.

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 uncertainty bounds 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.

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: the timestamp and the corresponding LMST in which the measurements where taken, Wind Sensor, Ground Temperature Sensor, Air Temperature Sensor, Ultraviolet Sensor, Humidity Sensor and Pressure Sensor.

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.

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. Humidity Sensor and Ultraviolet Sensor estimated uncertainties are set to NULL pending further revision and are expected to be released in the future. 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.

This

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, modeling 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 and atmospheric relative humidity, their estimated uncertainty bounds 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.

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.
• 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. Afterward, 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. Application of a model to obtain the atmospheric relative humidity.
• 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: the timestamp and the corresponding LMST in which the measurements where taken, Wind Sensor, Ground Temperature Sensor, Air Temperature Sensor, Ultraviolet Sensor, Humidity Sensor and Pressure Sensor.

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.

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.

In this release, wind sensor data are unavailable for this level due to calibration problems. Atmospheric relative humidity is also set to NULL pending further revision.

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 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.

Since at the moment of this release no data is available at this level for the Wind Sensor, its data is set to NULL and is expected to be released in the future. The same applies for the Humidity Sensor atmospheric relative humidity, its estimated uncertainties and the UV Sensor uncertainties.

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 has been subjected to estimations and corrections. To check the original data, refer to ENVRDR and TELRDR records.

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 ADR data set contains ancillary data used in the processing of REMS data. These data may come from sources external to REMS (as is the case of the rover positions), or derived from them (the UV dust attenuation is estimated from images of the rover cameras). They are bundled together and with the rest of the REMS data to make it easier its interpretation and its processing.

Data is a time ordered sequence of rows organized into several tables. Each data product contains one sol worth of activity.

Parameters

This data set includes the following information:

• Geometry information: solar longitude angle, solar zenithal angle, rover position, rover velocity, rover pitch, rover yaw, rover roll, masthead location and arm status. These data are provided by NAIF in SPICE kernels.
• Corrections information: estimated Ultraviolet Sensor signal attenuation due to dust deposition.

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.

Some of the ADR data, such as the rover and sun geometry, are provided directly by NAIF using SPICE. They are converted to ASCII tables following the conventions used in the rest of REMS data products.

Other ADR data, such as the Ultraviolet Sensor attenuation estimation, implies some processing. Dust attenuation magnitude over the Ultraviolet Sensor is estimated from rover cameras images taken at several moments during the mission. The cameras will take images of a target of the same size of the photodiodes situated near them. With a robust image processing algorithm it will be possible to estimate this attenuation factor.

Data

Each REMS ADR product in the data set is concatenation of ASCII tables. Each table contains similar ancillary data.

There are two tables: one for geometry information and another one for corrections. Each one contains the information outlined in the Parameters section above.

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.

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

In this data set, confidence depends on the reliability of the data coming from the external sources. In the case of geometry, data are SPICE kernels provided by NAIF. They are expected to be released as a separate data set. In the case of dust corrections, they are dependent on the quality of the rover cameras images and on the algorithm developed at CAB.

Data Coverage and Quality

At the time of this release, due to the low number of images of the Ultraviolet Sensor from sols 1 to sol 154, and the ongoing work of the signal attenuation estimation algorithm, the UV_DUST_ATTENUATION column is set to 1 (no attenuation) as a current best estimate. This factor may be updated as soon as there is more information available.

However, analysis of available data has revealed that the accumulation of dust over the Ultraviolet Sensor after sol 155 causes it to be attenuated above 10%, which is beyond the sensor operational requirements. When that happens, the UV_DUST_ATTENUATION column is set to NULL.

Limitations

The major limitation of this data set is its dependency on external sources.