Observing logs are simply a record of the observations.
You will find a careful log invaluable when it comes time to edit and calibrate your data. Please complete a log similar to previous log book entries. Some observers like to keep a record of the start and end times of every scan, and to note any unexpected effects apparent in the online visibilities. A record of data filenames is essential. If any fault occurs, no matter how trivial it seems , please note it in the Site Log Book .