A significant bug related to mosaicing (or primary beam correcting) of specific recent data has been uncovered in Miriad. The bug will affect data when all of the following apply: the data was observed since October 2003; mosaicing or primary beam correction of the data is important; the data has been loaded using an atlod with version date earlier than 23-Oct-04, and the data has been split with uvsplit with a version date of 16-Aug-04 or later. Note the version dates of atlod and uvsplit used on a dataset are recorded in the data history. The version dates of the currently installed versions are given whenever a task is executed.
The problem will become apparent at the imaging stage. Users are encouraged to update their version of Miriad to eliminate the bug. A simple procedure can be used to correct the problem in existing, partially reduced data.