NSSDCA ID: PSFP-00396
Availability: Archived at NSSDC, accessible from elsewhere
This description was generated automatically using input from the Planetary Data System.
Data Set Overview ================= The data set consists of calibrated observations, also known as CDRs. For all the CDR products there is a detached PDS label file that describes the contents of one data file. Each label file will have the same base name as the data file it is describing, with the extension .LBL to denote a label file. The label file defines the start time and end of the observation, product creation time, and the structure of the ASCII tables. Each data product is identified within the PDS label by a STANDARD_DATA_PRODUCT_ID value, shown in parentheses in the table below. The EPS portion of the data archive currently consists of seven CDR data products. The different CDR formats represent different Energy Resolution Spectra with different sampling rates. There is also a Pulse Height/Event Record file and one representing SCAN mode data. A given CDR data file will contain all the observations obtained on same earth day. The following table shows the different EPS data products. Following is a description of each of the current EPS CDRs. A more complete description of each may be found in the EPPS CDR SIS document, located in the DOCUMENT directory of the document volume. Current EPS Data Products: EPS Pulse Height (EPS_PULSE_HEIGHT) Contains Pulse Height Analysis data in ASCII table format. The lack of priority groups after the FSW6 load on 8/18/2008 means the weight and group columns of the data are not meaningful after that time. EPS High Resolution Spectra (EPS_HIRES_SPECTRA) High resolution (energy channels) ion and electron energy spectra. Replaces EPS_HI_SPECTRA after FSW6 (loaded on 8/18/2008). EPS Low Resolution Spectra (EPS_LORES_SPECTRA) Low resolution (energy channel) ion and electron energy spectra and rate counters. Replaces EPS_MED_SPECTRA after FSW6 (loaded on 8/18/2008). EPS Summary Spectra (EPS_SUMMARY_SPECTRA) Contains a subset of rate counters and low resolution energy spectra. CDR available only after FSW6 (8/18/2008). EPS Scan (EPS_SCAN_RATES) Contains the integrated hardware counters over four energy thresholds. Each threshold setting and integration lasts 1/4 second. Rates are reported in both raw and 'delta' form, see SIS document for details. CDR available only after FSW6 (8/18/2008). EPS High Priority EPS Spectra (EPS_HI_SPECTRA) This product contains high energy resolution spectra similar to the EPS_HIRES_SPECTRA product, but with the configuration from before the new FSW6 load on 8/18/2008. EPS Medium Priority EPS Spectra (EPS_MED_SPECTRA) This product contains lower energy resolution spectra similar to the EPS_LORES_SPECTRA product, but with the configuration from before the new FSW6 load on 8/18/2008. Instrument Overview =================== The EPS sensor consists of a 60-mm diameter, tuna-can-like cylinder, in which a start foil and stop foil, wrapped around opposite curved sides of the cylinder, constitute the TOF chamber. The detectors are arranged so that each detector senses the events within a given range of incidence angles. Each of the 6 detector modules is composed of 4 pixels: large and small ion and large and small electron. See the EPPSINST.CAT file for more information and [ANDREWSETAL2007] for full details. Calibration Overview ==================== This data set is calibrated. Spectral rates have been converted from raw counts to counts/sec and, where possible, to fluxes. Pulse height measurements are reported in calibrated keVs. See the calibration implementation document for details. Parameters ========== The accumulation times for spectral rate collection are programmable as described in the SIS document and in the EDR Dataset Catalog. For the CDRs, accumulation time is reported in the table directly so initial raw counts can be recovered from counts/sec by a simple multiplication. Calibration parameters are described in the Calibration Implementation document. Data ==== The EPS CDR data set products are described as follows (the STANDARD_ DATA_PRODUCT_ID value is given in parentheses). All data is in ASCII table format. The High Priority EPS Spectra (EPS_HI_SPECTRA_CDR) contains spectral data, hardware and software count rates and flux. [BEFORE FSW6, 8/18/2008] The Medium Priority EPS Spectra (EPS_MED_SPECTRA_CDR) contains spectral data, hardware and software count rates and flux. [BEFORE FSW6, 8/18/2008] The EPS High Resolution Spectra (EPS_HIRES_SPECTRA_CDR) contains high resolution (in energy) ion and electron energy spectra as count rates and flux. [AFTER FSW6, 8/18/2008] The EPS Low Resolution Spectra (EPS_LORES_SPECTRA_CDR) contains Low resolution (in energy) ion and electron energy spectra as count rates and flux and rate counters as count rates. [AFTER FSW6, 8/18/2008] The EPS Summary Spectra (EPS_SUMMARY_SPECTRA_CDR) contains the same quantities as the LORES data but sampled at the longer accumulation times of the HIRES data. [AFTER FSW6,8/18/2008] The EPS Scan (EPS_SCAN_SPECTRA_CDR) contains the integrated hardware counters over four energy thresholds. Each threshold setting and integration lasts 1/4 second reported as rates and differential inferred fluxes. [AFTER FSW6, 8/18/2008] The EPS Pulse Height CDR (EPS_PULSE_HEIGHT_CDR) contains Pulse Height Analysis data.
These data are available on-line from the Planetary Data System (PDS) at:
http://www.igpp.ucla.edu/public/pds/NSSDC/MESS-E_V_H_SW-EPPS-3-EPS-CDR-V1.0/
Questions and comments about this data collection can be directed to: Dr. David R. Williams
Name | Role | Original Affiliation | |
---|---|---|---|
Dr. George Ho | General Contact | Applied Physics Laboratory | george.ho@jhuapl.edu |