Table 2.
Summary of the target issues for each Data QA/QC module.
| Module | Issue category | Issue |
|---|---|---|
| Timestamp Alignment | Wrong timestamp specification |
• Misspecified beginning or ending timestamps • Timestamps not matched with time zone specification • Use of daylight saving time • Data streams not synchronized |
| Radiation measurement issue |
• Tilted radiation sensor • Shaded radiation measurements • Higher than expected radiation readings |
|
| Physical Range | Plausibility check |
• Excessive outlier (i.e., out-of-range) points • Percentage-ratio check (i.e., percentages provided as ratios) |
| Variability check |
• Trend • Step change • Repeating patterns or filled constants • Measurement or processing cut-off • Other unrecognized patterns |
|
| Multivariate Comparison | Short-term mismatch |
• Outlier (sporadically erroneous data) • Short-term mismatch (erroneous data for a specific period) • Shaded radiation (periodically erroneous data) |
| Unexpected relationship |
• Variables not synchronized in time • Derived one from another (perfectly fit) |
|
| Change of slope |
• Trend (systematic change in the regression slope) • Step change in full range (change in the regression slope) |
|
| Diurnal-Seasonal Pattern | Misalignment between median diurnal composite |
• Change of the sign convention • Shift in timestamps |
| Unexpected data ranges |
• Physically unlikely values • Excessive outlier • Step change in the full range |
|
| USTAR Filtering | FC-USTAR filtering |
• Filtered FC by USTAR threshold • Filtered USTAR |
| Variable Coverage | Unexpected variable coverage |
• Long data gaps • All empty columns • Missing mandatory variables • Mismatched or inconsistent variable naming |