In some cases, it is desirable to remove some frames (observations) from a group. For example, you make 5 observations of a source but you see that when the pipeline combines observation 3 into the group the noise is dominated by this observation. In order not to contaminate the group when observations 4 and 5 are coadded the pipeline must be instructed to remove observation 3 from any further group operations.
Observations can be turned off by using a special type of Orac-dr index file (cf. index files generated by skydip and calibration observations).
This index file is called index.badobs and should be present in the ORAC_DATA_OUT directory. It should
contain a line for each observation to be removed. Each line should contain the observation number
and the 8 digit UT date (YYYYMMDD), e.g.: