Notes about Data
The data ranges below should cover the majority of EPD configuration issues we’ve had throughout the ELFIN mission. For confirmation on suspicious looking data, please contact Ethan or Colin.
Calibrated Ion Data
Ion data with working on-orbit thresholds on ELFIN A began on 6/29/22, while for ELFIN B, it began on 7/6/22. That means data collected after this date can be used for science, once proper ground calibration is applied. Any data from before those two dates should be regarded with caution.
Off-nominal Sector Configuration on ELFIN-A
While testing 32 sectors on ELFIN-A, we accidentally overwrote the current configuration without noticing and it was not fixed for 1.5 months. Quality of data should not be impacted once modified phase delay corrections are applied.
Date Ranges Affected:
2022-03-15 12:53:00 to 2022-05-03 22:00:00 UTC on ELFIN A
Off-nominal EPD configuration on ELFIN-A
We could not determine root cause, but just one ELFIN-A collection seemed to occur using calibration configuration settings. The issue occurred solely on the instrument side, which has fewer diagnostics, so it is harder to pinpoint root cause. This data should be ignored.
Date Ranges Affected:
2022-01-03 01:10:00 to 2022-01-03 01:16:00 UTC on ELFIN A
Flight Computer Page Fault
ELFIN experiences occasional page faults (typically loss of power when reading or writing to flash memory). ELFIN B experienced a page fault late on 11/19/21 in a region of flash memory which holds the instrument configuration, resulting in data being collected in the instrument’s default (but incorrect) state. All EPD data recorded in this time range is irrecoverable and should be ignored.
Date Ranges Affected:
2022-06-18 00:00:00 to 2022-07-05 00:00:00 UTC on ELFIN B
2022-05-31 00:00:00 to 2022-06-14 00:00:00 UTC on ELFIN B
2021-11-19 20:00:00 to 2021-11-25 04:00:00 UTC on ELFIN B
SEP Event
Due to high-energy ion penetration during an SEP event, EPDe saw elevated background (at >~400keV) in the plasma sheet region. Please discard the fake relativistic electron signals from ELFIN-A and ELFIN-B in the plasma sheet region during the following time range.
Date Ranges Affected:
2022-01-14 23:00:00 to 2022-01-16 00:00:00 UTC on both ELFIN A and ELFIN B
2021-10-28 15:00:00 to 2021-11-04 11:00:00 UTC on both ELFIN A and ELFIN B
Low energy cutoff
An experimental threshold configuration on the EPDe was used, resulting in increased sensitivity. However, actual flux counts are inaccurate and energies below ~100 keV were cut off. Please disregard all EPDe data the following time ranges and satellites.
Date Ranges Affected:
2020-09-26 09:22:00 to 2020-09-28 08:12:00 UTC on ELFIN A
2020-10-18 07:35:06 to 2020-10-19 08:31:25 UTC on ELFIN B
2021-01-27 03:54:40 to 2021-02-23 01:56:23 UTC on ELFIN B