wiki:QC

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