MER2 (Spirit) MB Raw (EDR) Data Set Description Extracted from PDS3 Data Set Catalog File. Data Set Terse Description ========================== Mars Exploration Rover 2 Moessbauer Spectrometer raw science and instrument data. Data Set Description ==================== Data Set Overview ================= This data set is used to study the mineralogic composition of iron- bearing phases in Martian rocks and soils. For a Moessbauer experiment on any target, MIMOS II stores in memory for return to the Earth the following information: (1) a PHA spectrum for each of the 5 detectors; (2) five Moessbauer spectra (one reference and four sample spectra) for each of the 13 temperature intervals for a total of 65 spectra; (3) reference and sample temperatures; and (4) engineering data (e.g., the error signal for the velocity transducer). The Moessbauer spectra are in counts per channel for 512 channels. In (2), the four sample Moessbauer spectra in each temperature interval can selected in a number of ways. For example, they can be the 14.4 keV spectrum from each of the four detectors or the sum of the 14.4 and 6.4 keV spectra for each of the four detectors. Alternatively, the four spectra can be 14.4 and 6.4 keV spectra, each summed over two detectors. The spectra can be analyzed individually or combined to produce higher quality spectra. Combining spectra from different temperature intervals depended on how strongly the spectra depend on temperature. Processing ========== The raw data files are generated telemetry packets and are in the format that data are stored in the instrument aboard the spacecraft. The MB EDR data products were generated by the MIPL (Multimission Image Processing Laboratory) at JPL under the Operations Product Generation Subsystem using the telemetry processing software, mertelemproc. The raw data products are raw uncalibrated data reconstructed from telemetry data products. Metadata acquired from the telemetry data headers are used to populate the PDS label. There are not be multiple versions of an MB raw produce. If telemetry data is missing partial data products were created and the missing data were filled with (zeroes). The data were reprocessed after all data were received and the original version was overwritten. Data ==== A MB raw data product consists of five contiguous blocks of binary data or a single block and a detached ASCII PDS label. Each data block is 32 Kbytes long for a total size of 160 Kbytes or 32 Kbytes. The five data blocks are a copy of the instrument's memory buffer. The raw data file contains Moessbauer spectra for a given target measured in thirteen temperature windows, along with temperature data, an energy spectrum, a drive error signal spectrum, copies of the instrument parameter block and logbook. In addition, the file contains ten compressed Moessbauer spectra stored in the EEPROM as backup in case the instrument loses power. The backup spectra are updated during data acquisition, approximately every 6 minutes. Data from the instrument's SRAM occupy the first four blocks in the Moessbauer EDR data product. It contains three copies of the instrument parameter block, a drive error signal, temperature data, an energy spectrum, and Moessbauer spectra from 13 temperature windows. Each copy of the instrument parameter block in the SRAM is 512 bytes long. The SRAM has three copies of the parameter block for a total of 1536 bytes. The drive error signal, which monitors the operation of the MB drive unit, has 512 channels with two bytes per channel. The drive error signal values are stored in LSB first order. The MB EDR file contains temperature data recorded by three sensors: one on the electronics board, one on the sensor head, and one on the reference sensor. Each temperature value is scaled and stored as a two byte integer in MSB first order. The file contains 256 temperature records. Within each record, the order of values is board sensor, sample sensor, and reference sensor. The following equations contain the conversion of the scaled temperatures into Kelvin: The energy spectrum, which monitors the operation of the detectors, contains 256 channels of data for each of 5 detectors. Each value is a three byte integer stored in LSB first order. The data are aggregated so that data for the first detector are followed by data for the second detector and so on. Moessbauer data collected during a measurement are divided into temperature windows defined by a selectable lookup table. Each Moessbauer temperature window consists of five spectra (one for each detector). One spectrum contains 512 channels with three bytes per channel stored in LSB first order. The first channel of each spectrum gives the measurement lifetime, where lifetime is the number of cycles that the MB drive unit has executed during the measurement. The collection of MB spectra can be described as a three-dimensional array with axes of temperature window, detector, and channel, with the channel axis varying the fastest. The fifth data block of the MB EDR data file contains a copy of the instrument FRAM and EEPROM memory, along with copies of one Moessbauer temperature window, the drive error signal, instrument parameter block, and temperature data. The FRAM consists of three copies of the instrument parameter block and the instrument logbook. The logbook has 256 records with eight bytes in each record. The structure of the logbook is described in the Moessbauer Spectrometer Information Interface Control Document. The EEPROM contains ten compressed MB spectra. The data are compressed by combining data from several temperature windows or from several detectors. Each compressed MB spectrum has 512 channels with three bytes per channel stored in LSB first order. Reference ========= Klingelhöfer, G., et al. (2003) Athena MIMOS II Mössbauer spectrometer investigation, J. Geophys. Res., 108(E12), 8067, doi:10.1029/2003JE002138.