The Perl script sexpacman.pl takes one argument on the command line: the configuration file name (usually, but not necessarily, called sex.conf). The default command has been aliased to startsexpac, which also writes any output to a file sexpac.log for later inspection (See also Section 2.3.3). This script will run in an infinite loop, and the configuration file consists of a list of directories where it should look to find the particular files it needs. Here is an example of what such a file should look like:
In essense, sexpacman.pl is a wrapper program for corr_im_fast (Section 7.5) and SExtractor. It periodically scans the linkdir (defined in the configuration file) for new links to ROTSE-III images, created by camserverd (See Section 3.6). First, sexpacman.pl calls corr_im_fast to perform the dark- and flat-field corrections. Once an _c file has been created, sexpacman.pl calls SExtractor to process the corrected image. The resulting output yields three files: a list of objects (called an sobj file), an image which contains a measurement of the sky brightness of the image in a 6464 grid (called a sky file), and a file (usually called sobjlist) which is a list of the sobj files. This list file is monitored by idlpacman (Section 8.2.2) in order to calibrate the source lists against the USNO A2.0 catalog.
The process also creats a small, ``thumbnail'' version of each image in JPEG format which is copied via a cron job to the web server at UofM, and can be viewed in an archive on the web page at www.rotse.net. The most recent thumbnail is also displayed on the front page at that web site, and can be viewed through pressing a button on the real-time status monitor web page (Section 8.4.2). An example thumbnail is shown in Figure 8.2.