NSSDCA ID: PSFP-00690
Availability: Archived at NSSDC, accessible from elsewhere
This description was generated automatically using input from the Planetary Data System.
The Ion Mass Analyzer (IMA) provides in situ ion measurements in the energy range 0.01 - 40 keV/q for the main ion components H+, He++, He+, O+, with 20-80 amu/q to help satisfy the following scientific objectives: 1. Determine the instantaneous global distributions of plasma and neutral gas near Mars by providing undisturbed solar wind parameters 2. Define the local characteristics of the main plasma regions 3. Complement the ENA images Parameters: =========== All IMA data products have the same format and parameters, and each row (data file record) in the IMA SPREADSHEET data products has seven (7) COLUMN objects (parameters): 1. Start Time - Begin Date/Time in UTC of data samples 2. Stop Time - Ending Date/Time in UTC of data samples 3. Data Type Name - SENSOR or MODE. The SENSOR rows are the IMA science data for each mass channel (32 channels). The 32 SENSOR rows are followed by 10 rows of MODE data for the same time period. The MODE rows contain informational data such Mask indicators, Indexes, and Summations. 4. Data Type Id - Numeric ID indicating SENSOR or MODE. 5. Data Name - Short description for data on that row. For example 'Mass Channel x' where x = 0-31 to indicate the mass channel in the SENSOR rows or 'Polar Angle Index' for informational data (MODE row). 6. Data Unit - Indicates the data unit (c/acc for SENSOR data, unitless for MODE data). 7. Values - These are the actual data values. For this column there are multiple values as indicated by the ITEMS keyword in the label files. For IMA data, there are 96 ITEMS. In the SENSOR rows, these are the science data sampled for each energy step starting at 0 and ending at 95. The MODE data rows contain only one value each with remaining ITEMS indicated as 'missing' with nothing between the commas (value,,...,,). Please note that the data values are formatted for best accuracy and that this is not the accuracy of the IMA instrumentation. In addition, even though the IMA data are in units of c/acc (raw counts) which are typically integer values, the data are formatted with 2-3 decimal places to account for possible fractions that can occur due to onboard data compression and ground data decompression. Data Products: ============== The Standard Data Products for IMA PSA Level 1b (EDR) products are: 1. IMA_AZ00_C_ACC - Ion Mass Analyzer AZimuth anode 0 data in Counts / ACCumulation units. 2. IMA_AZ01_C_ACC - Ion Mass Analyzer AZimuth anode 1 data in Counts / ACCumulation units. 3. IMA_AZ02_C_ACC - Ion Mass Analyzer AZimuth anode 2 data in Counts / ACCumulation units. 4. IMA_AZ03_C_ACC - Ion Mass Analyzer AZimuth anode 3 data in Counts / ACCumulation units. 5. IMA_AZ04_C_ACC - Ion Mass Analyzer AZimuth anode 4 data in Counts / ACCumulation units. 6. IMA_AZ05_C_ACC - Ion Mass Analyzer AZimuth anode 5 data in Counts / ACCumulation units. 7. IMA_AZ06_C_ACC - Ion Mass Analyzer AZimuth anode 6 data in Counts / ACCumulation units. 8. IMA_AZ07_C_ACC - Ion Mass Analyzer AZimuth anode 7 data in Counts / ACCumulation units. 9. IMA_AZ08_C_ACC - Ion Mass Analyzer AZimuth anode 8 data in Counts / ACCumulation units. 10. IMA_AZ09_C_ACC - Ion Mass Analyzer AZimuth anode 9 data in Counts / ACCumulation units. 11. IMA_AZ10_C_ACC - Ion Mass Analyzer AZimuth anode 10 data in Counts / ACCumulation units. 12. IMA_AZ11_C_ACC - Ion Mass Analyzer AZimuth anode 11 data in Counts / ACCumulation units. 13. IMA_AZ12_C_ACC - Ion Mass Analyzer AZimuth anode 12 data in Counts / ACCumulation units. 14. IMA_AZ13_C_ACC - Ion Mass Analyzer AZimuth anode 13 data in Counts / ACCumulation units. 15. IMA_AZ14_C_ACC - Ion Mass Analyzer AZimuth anode 14 data in Counts / ACCumulation units. 16. IMA_AZ15_C_ACC - Ion Mass Analyzer AZimuth anode 15 data in Counts / ACCumulation units. Ancillary Data: =============== It is important for ASPERA-3 science studies to know where in space and time the Mars Express spacecraft and ASPERA-3 instruments are located and what objects (Sun, Mars, Earth, Phobos, Deimos) are in the fields of views. The ASPERA-3 view directions for each sensor can be derived using the SPICE kernels and software. The ASPERA-3 Sensor Frames and Geometry Information document (in DOCUMENT directory) provides a code example (in C and FORTRAN) for determining the view directions for the ASPERA-3 sensors. Coordinate System: ================== The ASPERA-3 data are always in the instrument reference frame since data are sampled in situ. The GEOMETRY table contains spacecraft related parameters expressed in the J2000 reference frame, and the ASPERA-3 Sensor Frames and Geometry Information document (in DOCUMENT directory) provides information for determining the ASPERA-3 sensors view directions and transforming to the J2000 reference frame. References: =========== Refer to the ASPERA-3 Experiment to Archive Interface Control Document (EAICD - MEX_ASPERA3_PSA_ICD_V02_00) found in the DOCUMENT directory for more information and detail concerning data set formulation and contents.
These data are available on-line from the Planetary Data System (PDS) at:
https://pds-ppi.igpp.ucla.edu/data/MEX-M-ASPERA3-2-EDR-IMA-V1.0/
Questions and comments about this data collection can be directed to: Dr. David R. Williams
Name | Role | Original Affiliation | |
---|---|---|---|
Prof. Rickard Lundin | Data Provider | Swedish Institute for Space Physics | rickard.lundin@irf.se |
Dr. Sandee J. Jeffers | General Contact | Southwest Research Institute | sandee.jeffers@swri.org |