Electric field instrument (EFI) Langmuir probe (LP) measurements at 2Hz
Thematic areas: Plasma measurements, Space Weather
Applicable missions: Swarm
Applicable spacecraft: Swarm-A, Swarm-B, Swarm-C
The EFIx_LP_1B Product contains plasma data from the Langmuir Probe (LP) of the Electrical Field Instrument (EFI). The plasma product encompasses the plasma density and temperature. Data is provided at 2 Hz rate. The time instant are determined by the EFI instruments. No interpolation of the EFI data is performed, neither to shift the measurements in time nor to fill any gaps.
N/A
(delivered separately)
| Variable | Units | Description | Dim | Type |
|---|---|---|---|---|
| Timestamp | UTC | Time stamp | 1 | CDF_EPOCH |
| SyncStatus | - | Synchronization status | 1 | CDF_UINT2 |
| Latitude | deg | Position in ITRF – Geocentric Latitude | 1 | CDF_DOUBLE |
| Longitude | deg | Position in ITRF – Geocentric Longitude | 1 | CDF_DOUBLE |
| Radius | m | Position in ITRF – Radius | 1 | CDF_DOUBLE |
| U_orbit | m/s | Magnitude of spacecraft velocity in the ITRF | 1 | CDF_DOUBLE |
| Ne | cm-3 | Plasma density (electron) | 1 | CDF_DOUBLE |
| Ne_error | cm-3 | Error of the plasma density estimate | 1 | CDF_DOUBLE |
| Te | K | Plasma electron temperature | 1 | CDF_DOUBLE |
| Te_error | K | Error of the plasma electron temperature estimate | 1 | CDF_DOUBLE |
| Vs | V | Spacecraft potential | 1 | CDF_DOUBLE |
| Vs_error | V | Error of the spacecraft potential estimate | 1 | CDF_DOUBLE |
| Flags_LP | - | Flags indicating the source/method of LP measurements (ne, Te, Vs) | 1 | CDF_UINT1 |
| Flags_Ne | - | Flags characterizing the plasma density measurement | 1 | CDF_UINT1 |
| Flags_Te | - | Flags characterizing the electron temperature measurement | 1 | CDF_UINT1 |
| Flags_Vs | - | Flags characterizing the spacecraft potential measurement | 1 | CDF_UINT1 |
| Flag |
Value |
Description |
|---|---|---|
| Flags_LP |
1 |
High gain probe has no errors |
| 3 |
High gain probe has errors, instead partially the low gain probe was used. See Flags_Te for implications. |
|
| 9 |
Data is from duplicated harmonic mode because of on-going sweep, it is recommended to discard these duplicate data |
|
| Flags_Ne |
10 |
Nominal data, calibration error for this sample is computed |
| 19 |
Nominal data, but calibration error not computed/out of range |
|
| 20 |
Nominal data, error for this sample is not computed |
|
| 30 |
The estimate is from low gain probe, Ne estimate probably has a larger random error than the nominal high gain probe |
|
| 40 |
Negative density (high positive values, even extremes, are not flagged) |
|
| Flags_Te |
10 |
Nominal data, calibration error for this sample is computed |
| 19 |
Nominal data, but calibration error not computed/out of range |
|
| 20 |
Nominal data, error for this sample is not computed |
|
| 12 |
Calibration error for this sample is computed, but ADC overflow at the linear bias, high gain probe, tracking ok, but discard Te is recommended |
|
| 15 |
Calibration error for this sample is computed, but ADC overflow at the linear bias, low gain probe, tracking ok, but discard Te is recommended |
|
| 22 |
Error for this sample is not computed, ADC overflow at the linear bias, high gain probe, tracking ok, but discard Te is recommended |
|
| 25 |
Error for this sample is not computed, ADC overflow at the linear bias, low gain probe, tracking ok, but discard Te is recommended |
|
| 32 |
Failed tracking, high gain probe, discard Te is recommended |
|
| 35 |
Failed tracking, low gain probe, discard Te is recommended |
|
| 36 |
Extreme value, discard Te is recommended |
|
| 40 |
Negative Te value, discard Te is recommended |
|
| 41 |
ADC overflow at the retarded bias, high gain probe, discard Te is recommended |
|
| 44 |
Wrong bias order, discard Te is recommended |
|
| 46 |
ADC overflow at the retarded bias, low gain probe, discard Te |
|
| Flags_Vs |
10 |
Nominal data, calibration error for this sample is computed |
| 20 |
Nominal data, error for this sample is not computed |
|
| 25 |
ADC overflow at the retard bias, discarding Vs is recommend |
|
| 26 |
ADC overflow at the linear bias, discarding Vs is recommend |
|
| 30 |
Failed tracking, discarding Vs is recommend |
|
| 33 |
Value of Vs is unreasonable, discarding Vs is recommended |
Level 1B Product Descriptions:
Level 1B Product Format page:
N/A