RPW Data Center
solo_L3_rpw-tnr-surv-flux
The data product solo_L3_rpw-tnr-surv-flux provides fully calibrated E-field spectra, measured in survey normal and burst modes over the 4 frequency bands – A, B, C and D - of the TNR receiver of the Solar Orbiter/RPW instrument.
DOI: https://doi.org/10.57780/ESA-3XCJD4W
Publisher: ESA
Citation: European Space Agency & Maksimovic, M. (2024). RPW, Radio and Plasma Waves instrument (Version v1.0) [Dataset]. European Space Agency. https://doi.org/10.57780/ESA-3XCJD4W
Link to the data repository
Data files are available from the Solar Orbiter Archive home page.
Copies of the files are also stored in the LIRA local data repository.
Data product overview
The radio flux density is given in physical units (W/m^2/Hz or SFU). The calibration takes already account of the harness + pre-amplifiers + antennas gain/phase contributions.
The receiver background is already removed from the signal. The antenna calibration method is presented in this paper.
| Type of data | Spectrum |
|---|---|
| Intensity units | W/m^2/Hz or SFU or dB |
| Frequency range | 4 to 978 kHz |
| Frequency number | 128 |
| Frequency step | 4.5% * f |
| Frequency scale | Log |
| Time resolution | 1s to 12s |
| Data format | CDF |
| File name | solo_L3_rpw-tnr-surv-flux_[YYYYMMDD]_V[version].cdf |
| Granularity | 1 file per day |
| Expected data volume | 25 MBytes per file |
Data organization
Each CDF record contains data for a given TNR frequency spectrum (also called sweep hereafter). Each sweep covers the 128 frequencies of the 4 TNR bands.
Epoch times correspond to the acquisition time of the first data sample in the current TNR sweep. The acquisition times for next data samples in the sweep can be computed using the offset values (in seconds) in the ELAPSED_TIME_SINCE_EPOCH zVariable. Missing/bad data samples are interpolated.
Table below gives the name, data type, units and description of the main zVariables stored in the CDF file.
In the the “TYPE” column, the expected size (i.e., number of elements along each dimension) of the zVariable for a CDF record is given between bracket (e.g., “[1]”).
Non-record-variant zVariables are indicated by a “(NRV)” additional label in the “TYPE” column.
| NAME | TYPE | UNIT | DESCRIPTION |
|---|---|---|---|
| Epoch | CDF_TIME_TT2000 [1] | ns | Epoch time of the record Taken at the acquisition time of the first data sample in the current TNR sweep |
| FREQUENCY | CDF_FLOAT[128] (NRV) | Hz | TNR frequency values |
| SENSOR_CONFIG | CDF_UINT1[1] | unitless | Channel receiver antenna configuration. Possible values are: 1 (V1) 2 (V2) 3 (V3) 4 (V1-V2) 5 (V2-V3) 6 (V3-V1) |
| ELAPSED_TIME_SINCE_EPOCH | CDF_FLOAT[128] | s | Elapsed time in seconds since the beginning of the current sweep |
| INTERPOL_FLAG | CDF_UINT1[128] | unitless | Flag that indicates the state of the current record. Possible values are: 0 = no data sample, 1 = real data sample, 2 = interpolated data sample, 3 = data sample amplitude is below background |
| PSD_V2 | CDF_FLOAT[128] | V^2/Hz | Power spectral density measured by the TNR receiver (preamplifier contribution is included) |
| PSD_FLUX | CDF_FLOAT[128] | W/m2/Hz | Radio flux density in physical units measured at the spacecraft location, after receiver background subtraction and antenna calibration |
| PSD_SFU | CDF_FLOAT[128] | sfu | Radio flux density in Solar flux units (i.e., 10^22 W/(m^2 Hz)) normalized to 1 AU, after receiver background substraction and antenna calibration |
| PSD_SFU_DB | CDF_FLOAT[128] | unitless | Normalized Radio flux density in dB measured at the spacecraft location. Values are computed using the relation 10*alog10(PSD_FLUX / BG), where BG is an estimation of the background computed from the 1% percentile of the signal for each frequency. |
| SC_POS_HCI | CDF_FLOAT[3] | km | Spacecraft position in the Heliocentric Inertial (HCI) system |
Rules of use
Please read the text of the Rules_of_use global attribute in the CDF files.
See also in https://rpw-datacenter.obspm.fr/spip.php?article4.
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) |
|---|---|
| Some RPW TNR frequency channels are affected by Electromagnetic contaminations. | TNR E-field spectra are interpolated over the 50 cleanest frequency channels. |
| RPW MY (3) electrical antenna signal was lost intermittently between November 13th and March 15th. TNR acquisitions were impacted when measurements were performed on this antenna or dipoles V3-V1 and V2-V3 | Specific entry added for the global attribute CAVEATS and QUALITY_FLAG zVariable set to 1 for impacted records. |
Release notes
See MODS global attribute in the CDF files for an history of the data modifications.
Authors
Antonio Vecchio, Xavier Bonnin, Quynh Nhu Nguyen and Milan Maksimovic, with the support of Vratislav Krupar
References
• The Solar Orbiter Radio and Plasma Waves (RPW) instrument, Maksimovic et al., A&A, 2020 (https://doi.org/10.1051/0004-6361/201936214)
• Solar Orbiter/RPW antenna calibration in the radio domain and its application to type III burst observations, Vecchio et al., A&A, 2021 (https://doi.org/10.1051/0004-6361/202140988)
• THR-Calibration Procedures, A. Vecchio, [ROC-TST-CAL-PRC-00031-LES 1.0] (available on demand)
• Metadata Definition for Solar Orbiter Science Data, Helen R. Middleton
• RPW Data Product Description Document (DPDD)
• NASA CDF Web portal
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