An option is also available to run in automatic mode. Using this option, the program will ask you for the maximum angle between the source and the pointing direction that you wish to consider. It then searches through the EGRET timeline file to find all viewing periods where the source was within that angle of the pointing direction. The program then does the analysis once for each individual viewing period.
If you choose the manual mode you must type in the viewing periods you wish to analyze. You may enter multiple viewing periods or a single viewing period. You may also enter sub-intervals of viewing periods by typing in the starting and ending times of the interval you wish to analyze although periods shorter than one orbit will be interpreted as an orbit in length. Kburst will prompt you for all of this information.
One of the most difficult jobs for the kb code is to correctly break up the xpose output into orbits. There are no clear unambiguous signals in the xpose output file to indicate with 100% accuracy the beginning and ending of orbits. This problem is solved as follows:
A file is maintained called 'vp_occul.dat'. As mentioned above, this file is used by the kb code to determine orbit boundaries. For each CGRO viewing period, there is an entry that contains the year, the day and fractional day of the exact center of an occultation somewhere in the viewing period and finally the orbit period in minutes.
IMPORTANT: This part of the program needs to be maintained! A new entry must be added to the file for each new viewing period. Future updates to this file may be supplied by EGRET team member David Kendig firstname.lastname@example.org.