RPW Data Center
solo_L2_rpw-tds-surv-stat
The solo_L2_rpw-tds-surv-stat data provides TDS on-board statistics, measured in SURVEY NORMAL and BURST modes. This short data packet contains several statistical quantities describing the waveform snapshots processed by the TDS detection algorithm, including also those which were not selected for download as triggered snapshots. Nominally, TDS processes one waveform snapshot every second and the STAT packet transmitted every 16 seconds contains averages and counts accumulated over the past 16 seconds. Included is the number of detected waves and dust impacts, the peak and RMS amplitudes of detected waves, median value of the frequencies of detected waves, and the maximum absolute value and an RMS value calculated from all processed snapshots. The statistics is only calculated from one TDS channel selected by a telecommand.
DOI: https://doi.org/10.57780/esa-3xcjd4w
| Type of data | Time series |
|---|---|
| Units | V/m, counts, Frequency |
| Time resolution | 16 seconds |
| Data format | CDF (3.9.0) |
| Granularity | 1 file per day |
Data organization
Each CDF record in the file contains TDS statistics from one channel of the electric field, as indicated in CHANNEL_ON and CHANNEL_REF (selected by a telecommand). The calibrated values of the electric field data (V/m) in sensor coordinates are stored in WA_AMP_MAX, WA_AMP_MED, WA_AMP_RMS, SN_MED_MAX_E, and SN_RMS_E variables. The calibration is done by a constant, frequency independent factor for each antenna, corresponding to instrument gain at approximately 50 kHz.
The Epoch time (CDF_TIME_TT2000) of each record represents the acquisition time of the first data sample in the selection time interval.
Table below gives the name, data type, units and description of the zVariables stored in the CDF file.
| NAME | TYPE | UNIT | DESCRIPTION |
|---|---|---|---|
| Epoch | CDF_TIME_TT2000 | ns | Primary time used as a reference in the file. Corresponds to the time of the first sample of the snapshot. |
| CALIBRATION_TABLE_INDEX | CDF_UINT1[2] | unitless | Index of SWF calibration table |
| QUALITY_FLAG | CDF_UINT1 | unitless | Flag to indicate the quality of the data. 0 – Bad data; 1 – Known problems, use at your own risk; 2 – Survey data, possibly not publication-quality; 3 Good for publication, subject to PI approval; 4 - Excellent data. |
| QUALITY_BITMASK | CDF_UINT2 | unitless | Flag to indicate any context information or status at the receiver or experiment level. Forwarded from L1 data. |
| QUALITY_FACT | CDF_UINT2 | unitless | Flag to indicate any context information or status at the receiver or experiment level. |
| L2_QUALITY_BITMASK | CDF_UINT2 | unitless | Flag to indicate any context information or status at the receiver or experiment level. |
| SURVEY_MODE | CDF_UINT1 | unitless | Flag to indicate if the receiver in the SURVEY_BURST (=1) or SURVEY_NORMAL (=0) mode. |
| BIAS_ON | CDF_UINT1 | unitless | Non-zero if BIAS powered on. |
| BIAS1_ON | CDF_UINT1 | unitless | Non-zero if biasing active on ANT1. |
| BIAS2_ON | CDF_UINT1 | unitless | Non-zero if biasing active on ANT2. |
| BIAS3_ON | CDF_UINT1 | unitless | Non-zero if biasing active on ANT3. |
| BIAS_HV_ON | CDF_UINT1 | unitless | Non-zero if BIAS High Voltage active. |
| BIAS_MUX_MODE | CDF_UINT1 | unitless | BIAS MUX setting |
| RPW_THR_ON | CDF_UINT1 | unitless | Non-zero value indicates THR was powered on. |
| RPW_LFR_ON | CDF_UINT1 | unitless | Non-zero value indicates LFR was powered on. |
| RPW_ANT1_ON | CDF_UINT1 | unitless | Non-zero value indicates preamplifier on antenna 1 was powered on. |
| RPW_ANT2_ON | CDF_UINT1 | unitless | Non-zero value indicates preamplifier on antenna 2 was powered on. |
| RPW_ANT3_ON | CDF_UINT1 | unitless | Non-zero value indicates preamplifier on antenna 3 was powered on. |
| RPW_SCM_ON | CDF_UINT1 | unitless | Non-zero value indicates SCM sensor was powered on. |
| RPW_SCM_CALIB | CDF_UINT1 | unitless | Non-zero if SCM calibration signal is active. |
| SAMPLING_RATE | CDF_REAL4 | Hz | Sampling rate of the snapshot in Hz (262 or 524 kHz). |
| SNAPSHOT_LEN | CDF_UINT4 | samples | Length (in samples) of each snapshot processed by the TDS SW to build these statistics |
| TDS_CONFIG_LABEL | CDF_CHAR | unitless | Text representation of TDS input configuration. Can be: “SE1”, “DIFF1” or “XLD1’’. See Table 1. for interpretation. |
| SNAPSHOT_SEQ_NR | CDF_UINT2 | unitless | Sequential number of a snapshot incremented with every snapshot |
| CHANNEL_REF | CDF_UINT1 | unitless | Configuration of the input signal for the statistics. A decadic number AB, where the digits A and B indicate a combination of RPW antennas in this channel (0=GND 1=V1, 2=V2, 3=V3). The number AB indicates that the corresponding channel contains a difference of 2 channels A-B. For example, value of 31 indicates dipole V3-V1. |
| SN_MED_MAX_E | CDF_REAL4 | V/m | For each snapshot a maximum absolute value from all samples is calculated. This value gives the median value of these maxima from all snapshots. |
| SN_RMS_E | CDF_REAL4 | V/m | RMS of E field over all proceeded snapshots. |
| SN_THRESHOLD | CDF_UINT1 | unitless | Number of snapshots in the covered period where the maximum amplitude (maximum absolute value) exceeded the threshold from all samples is calculated. This value gives the median value of these maxima from all snapshots. |
| DU_NR_IMPACT | CDF_UINT1 | counts | Total number of valid snapshots processed during the statistics collection period and identified as dust impacts from all samples is calculated. This value gives the median value of these maxima from all snapshots. |
| DU_MED_AMP | CDF_REAL4 | V/m | Median amplitude of the dust spikes. For each snapshot identified as dust, TDS SW calculates the amplitude of the largest spike dust impacts from all samples is calculated. This value gives the median value of these maxima from all snapshots. |
| WA_AMP_MAX | CDF_REAL4 | V/m | Maximum of maxima of the amplitude of waves. For each snapshot identified as a wave, a maximum absolute value from all samples is calculated |
| WA_AMP_MED | CDF_REAL4 | V/m | Median of the peak amplitudes of waves. For each snapshot identified as a wave, a maximum absolute value from all samples is calculated |
| WA_RMS | CDF_REAL4 | V/m | RMS value calculated form all waves |
| WA_NR_EVENTS | CDF_UINT1 | counts | Total number of valid snapshots processed during the statistics collection period and identified as dust impacts from all samples is calculated. This value gives the median value of these maxima from all snapshots. |
| WA_MED_FREQ | CDF_REAL4 | Hz | Median frequency of all identified waves. This value is calculated from the largest peak in the averaged FFT and encoded logarithmically in an 8-bit value |
Caveats and known issues
Table below gives the list of main known issues and the actions taken to mitigate them.
Please read the CAVEATS global attribute entries in the CDF files to be aware of the possible issues and limitations concerning data.
| ISSUE | MITIGATION(S) |
|---|---|
| RPW MY (3) electrical antenna signal was lost intermittently between November 2023 and February 28, 2024. TDS acquisitions were impacted when measurements were performed on this antenna. | TDS receiver was switched into the monopole mode (SE1) configuration. |
Release notes
See MODS global attribute in the CDF files for an history of the data modifications.
Authors
David Pisa, and Jan Soucek.
References
• The Solar Orbiter Radio and Plasma Waves (RPW) instrument, Maksimovic et al., A&A, 2020 (https://doi.org/10.1051/0004-6361/201936214)
• Metadata Definition for Solar Orbiter Science Data, Helen R. Middleton
• RPW Data Product Description Document (DPDD)
• NASA CDF Web portal
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