At the SAS 2004 conference, someone suggested to me that a good test of ACPS would be to try the Messier Marathon. To that end, I wrote a script to generate RTML for the Marathon objects, and imported the batch into the schedule database. You can retrieve a ZIP file with the script and RTML here. You can play around with the exposure time, etc., in the script, regenerate the RTML, import and test with the simulator.

In order to get all of the Marathon objects, it was necessary to set things up a bit unusually. First, it's not possible to reach the extreme west and east targets if you wait till official astronomical night, which is when the sun is at -18 degrees elevation. I changed the scheduler engine's setting to -12 degrees. People told me that you have to start at twilight. Second, the simulated observatory had to be set to a zero degree minimum elevation. These adjustments were needed to avoid having some targets reported as "unreachable" by the scheduler. They didn't add much time to the run.

Conditions

• Location: Mesa, AZ
• Starting on March 20, 2004 at 0234 UTC
• Start and stop at -12 deg. sun elevation
• Allow observing down to 0 degrees elevation
• Dispatcher set to "Prefer West" and "Prefer Short Slews"
• 110 targets, per the SEDS Marathon website
• Exposure time 180 seconds
• Slew rate 5 deg/sec
• Slew settle time 2 sec
• Image download time 10 sec.
• Unguided exposures (no guider overhead)

Results

All 110 targets were acquired with time to spare. The charts below show the details of the run. These charts were produced with the standard Run Detail Plotter that comes with ACPS. Click the images below to see them full size. Use your browser's back arrow to reurn to this page.

The Timing chart shows that the scheduler had to wait for some of the eastern targets to rise into view before acquiring them. You can also see the sweep from west to east in the Meridian chart.

---