Often, the user will know that there is on-board coverage of a certain interval before attempting to correct the moments. Conversely, it is possible to run the software `blind' - i.e. to attempt to correct an interval about which you have no prior knowledge of coverage. If there are any moments within the interval requested (and there is associated data such as AUX (attitude) data), then those moments will be corrected. The start and end times of these moments may represent only a short portion of the input start and end times (and this will be conveyed in the summary at the end of the calculation), however the filename will contain the input times as part of its construction. This could be slightly misleading to the unwary, so it is advisable to consult the command history of PEACE (or use the -history option). Note that if the EFW and/or FGM data is not found, then the correction will still proceed, but for the potential a constant user-defined value (default 7 V) will be used and/or no anisotropy will be estimated. Again, this is conveyed to the user on the console.
Instead of running the corrector blind, you may wish to try to access and correct all the moments over a long duration (you would construct a script to accomplish this). Now the optimal data interval length becomes important, since the user must consider the managability of file sizes, and the possibility of reducing losses of data if the calculation fails during a particularly long run. Probably the maximum/optimal data interval (from existing user experience) is about 4 hours. This way, output files are easily managable, and each correction pass is relatively fast. Another way to speed up calculation on long batch operations is to make the guess loop step resolution quite coarse, and, erring on the side of caution, make the loop quite large (say -l-1000, -u1000, -r100).
Batch mode scripts can be written in your preferred language, for example Csh or Perl. The simple looping and arithmetic capabilties of scripting languages allow the user to construct powerful automated correcting facilities. Note that QTMC prints information to the console for (a) promotion of data, (b) progress of the calculation and (c) summary of calculation. In batch mode you should redirect this output to a file (say called console.log) and watch its progress with tail. For example, to execute the script `qtmcbatch':
@> chmod +x qtmcbatchMake the script executable (could also use chmod 755)
@> qtmcbatch > console.log &Run script in background and redirect output to log file
@> tail -f console.logWatch progress of console.log. Kill with Ctrl+C