Where can I find the BAT enable-disable map for a given observation?
BAT enable-disable maps are presently organized by *time*, not observation number. They are stored in the bat/hk directory of an observation, and follow the format: swt[obsid]bdecb.fits. The “swt” at the beginning of the file name indicates that the value in the file name is the mission elapsed time of the first map in the file. It is quite possible for an enable map generated during one observation to be included in the subdirectory of a different observation. The maps are produced on-board as needed, not according to any ground-defined schedule. The ground processing pipeline is meant to find the nearest map in time. A reprocessing of existing Swift data is planned soon, which will, among other things, merge any files into a single one, and rename each one according to the observation number. Until then it is safe to take the first file. This is usually appropriate for GRBs since the GRB occurs at the beginning of the first observation snapshot.
