QC definition - ORAC-CC/orac GitHub Wiki
Understanding the Quality Control Flag
The ORAC outputs contain a field called 'qcflag'. It is a bit mask highlighting where the retrieval has exceeded prescribed limits:
| Bit # | Flags | Details |
|---|---|---|
| 0 | Excessive uncertainty in optical thickness | > 0.08 |
| 1 | Excessive uncertainty in effective radius | > 3.0 um |
| 2 | Excessive uncertainty in cloud top pressure | > 200 hPa |
| 3 | Excessive uncertainty in cloud fraction | > 0.2 |
| 4 | Excessive uncertainty in surface temperature | > 2 K |
| 5 | Lack of convergence | Change in cost > (0.05 * # of measurements) over 40 iterations |
| 6 | Excessive cost | > 100.0 |