About the verification of the RPW data quality.
RPW QUALITY_BITMASK CDF VARIABLE
Definition
The formal definition of the QUALITY_BITMASK CDF zVariable is provided in the "Metadata Definition for Solar Orbiter Science Data" document (SOL-SGS-TN-0009). There is one value per CDF record.
For RPW L1 CDF
WARNING: QUALITY_BITMASK SETTING IS NOT FULLY IMPLEMENTED IN L1 CDF
The QUALITY_BITMASK CDF_UINT2 zVariable in the RPW L1 CDFs is set by the RPW operations and data pipeline (RODP) hosted at LESIA.
Table below gives the list of possible values for L1 CDFs. It assumes that these values are common to all RPW L1 CDF products.
| Bit | Decimal value | Meaning | Justification | Computation | Comment |
| RPW +Z ANT PA in the line of sight of the HGA during TX ON. | The HGA TX may have an impact on the RPW science measurement quality when the ANT PA in the HGA light of sight | To be determinated by ROC from SPICE computation | |||
| SPICE Heat Shield Door is open | SPICE HSD may have an impact on the RPW +Z ANT bending effect | Known from HSD_SPICE_OPEN E-FECS event | |||
| LFR setting has changed before the end of the current data samples acquisition | According to LFR data acquisition mechanism and CDF structure, it can be impossible for some dataset (i.e., SWF) to take of a LFR setting change - performed via a command execution on-board - in a CDF record time window. Users need nevertheless to be warned when such LFR setting change occurred during a data sample acquisition. | Known from the reception of the TM_LFR_TC_EXE_SUCCESS {YIW00139} S1 TM that confirms the LFR setting change | |||
| Possible SWA-PAS high voltage contamination | SWA-PAS unit may provoke noise on RPW measurements | Inclusion of this event into the bitmask is TBC (quantification of the impact is TBD) | |||
| EMC QUIET window | SolO payload is in EMC QUIET mode | Known from EMC_MAND_QUIET E-FECS event | |||
| EMC NOISY window | SolO payload is in EMC QUIET mode | Known from EMC_PREF_NOISY E-FECS event | |||
| Spacecraft roll manœuvre | Indicate when the spacecraft perform rolls | Known from *_ROLL E-FECS event | |||
| Thruster firings | Indicate when the plateform thruster firings happen | Known from TMC+WOL E-FECS event | |||
| BIAS1_SWEEP - ongoing sweep | Ongoing sweep on one probe. | Should be set from 100 ms before the sweep to 1 s after the sweep on a particular probe. | |||
| BIAS2_SWEEP - ongoing sweep | |||||
| BIAS3_SWEEP - ongoing sweep | |||||
| BIAS1_CURRENT_NONCONSTANT | Changes in biasing current may (1) not be instantaneous, and (2) may have uncertain timestamps. | Should be set from 100 ms before to 1 s after any change in bias current on a particular probe (including sweeps). | |||
| BIAS2_CURRENT_NONCONSTANT | |||||
| BIAS3_CURRENT_NONCONSTANT | |||||
For RPW L2 CDF
The zVariable QUALITY_BITMASK is set in the L1 CDF by the RPW data pipeline at LESIA and must not be changed by the RPW Calibration Software (RCS) when producing the L2 CDF. QUALITY_BITMASK bits allocated in L1 CDF must be saved "as is" in L2 CDF. To store information specific to L2 data, please use the dedicated L2_QUALITY_BITMASK CDF_UINT2 zVariable instead.
The optional CDF_UINT2 zVariable L2_QUALITY_BITMASK can be used instead in the RPW L2 CDF, in order to provide information related to the equipment. The name of this zVariable must be the same in all the L2 CDF, but the bit meaning can different.
Table below gives the list of values to be set in L2 CDF by RCS.
INSTRUCTION: Table to be filled with extra information to be passed by RCS in the L2 CDF QUALITY_BITMASK zVar using free bits. "Bit" and "Decimal value" columns should be let free for the moment. "Comment" column can be used to specify the L2 CDF product(s) for which the QUALITY_BITMASK zVar must be set (if it is not specified, it is assumed that all L2 CDF products requires this information).
| Bit | Decimal value | Meaning | Justification | Computation | Comment |
| 0 | SCM outworking or unknown temperature | Indicate when the SCM temperature are out of working range | known from HK_LFR_TEMP_SCM T< -55°C or T> +85°C | Values defined by SCMCAL in the L2 magnetical data (-B) CDFs only | |
| 1 | SCM heater on/off transition | indicate EMC transient: - SCM heater on/off | - Known from HK_PDU_HEATER_CURRENT | Values defined by SCMCAL in the L2 magnetical data (-B) CDFs only | |
| 2 | LFR onboard calibration signal | Indicate when the LFR send calibration signal to SCM | known from HK_LFR_CALIB_ENABLED | Values defined by SCMCAL in the L2 magnetical data (-B) CDFs only |
RPW QUALITY_FLAG CDF VARIABLE
Definition
The formal definition of the QUALITY_FLAG CDF zVariable is provided in the "Metadata Definition for Solar Orbiter Science Data" document (SOL-SGS-TN-0009). There is one value per CDF record.
The possible values of the QUALITY_FLAG CDF zVariable are reported in the following table for convenience.
| Quality | Meaning |
|---|---|
| 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 which has received special treatment |
Implementation plan
The QUALITY_FLAG values of the RPW L1 CDF are all set to "3" by default.
From this initial status, the RCS must then decide in an autonomous way to change or not the value of QUALITY_FLAG records, when transferring the quality information to the output RPW CDF. The RCS decision must rely on relevant data (i.e, QUALITY_BITMASK, other data, parent data, etc.) as explained in the next section.
Computation
The detailed computation of the QUALITY_FLAG for each RPW L1R/L2 data product must be given in the RCS Software Requirements Specification (SRS) documents (see RPW Calibration Software Documentation).
RESOURCES
- The RPW science Data Validation and Verification Plan (DVVP) is available in https://confluence-lesia.obspm.fr/download/attachments/3113240/ROC-GEN-SCI-PLN-00077-LES_Iss01_Rev00%28RPW_DVVP%29.draft-2019011.pdf?version=1&modificationDate=1549625875889&api=v2
- Feedback from Clusted by Yury Khotyaintsev (IRFU): bitmask_quality.pdf