APT Plan generator was born from a frustration: how to visit several targets during the night without sitting in front of the computer. I like to visit supernovae, but each doesn't need much time: about 30 minutes for each separate target. So over a summer night, I could visit 9 or 10 supernovae. In the winter much more. APT has the ability to create plans, but it's a very time consuming activity if your plan changes every night: stop guiding, move to a target, plate solve and check, start guiding, take photos, and so on. Creating a plan for 10 targets could take a very long time and would be prone to errors. So I looked into a way to automate that. This is how APT Plan Generator (APTPG) was born.
Using APTPG is simple: when it starts, choose from the "Data" menu whether you want to visit supernovae or DSO targets. APTPG was created with supernovae in mind, but works (albeit a bit slowly) with DSO targets too (a catalog is provided).
The screen has the following sections:
- At the top, the parameters of your plan: the plan name (which you'll see in APT's list of plans), the path to APT's log file (look for APT.xml on your disk), whether you use a digital camera or a CCD camera (as defined by APT), the start time of your plan(3) (important so that APTPG can create a schedule), the latitude/longitude of the observer, your hemisphere, the length of pauses in the plan for times when nothing needs to be done (600, i.e. 10 minutes, is usually good), the minimum altitude the targets need to be at to be considered for the plan (most people would use 30 degrees or so), the maximum magnitude you want the targets to be (this depends in part on the capabilities of your hardware and the time you want to spend on each target), the length of each exposure (individual image), and the number of exposures per target.
- A list of the targets in the catalog that match the search criteria.
- A graph showing the altitude of the selected targets over time during the night (i.e. between sunset and sunrise).
- Combo boxes to chose the sorting of the table, and 3 action buttons: "Reset", which unselects the targets in the table; "Reload", which reloads the data into the table, i.e. after changing some of the parameters of the plan; "Generate" that schedules the targets and inserts them into APT's plans.
Once you have selected the targets you're interested in, click "Generate". This will run a genetic algorithm (GA) that will try to schedule your targets between the start time you provided and the end of the night(1). If the GA finds a suitable schedule, it will be shown to you with the name of the targets and P (for pause when nothing needs to be done). If you confirm you want to use that plan, click "OK" and the plan will be added to APT's light plans(2). If you click "Cancel" the schedule is abandonned and APT isn't modified.
Now start APT (don't run APTPG while APT is running as APT will wipe the new plan when it exits if it didn't exist when it was started). In your light plans, you should see your schedule. Select it and start it at the time you specified in APTPG as start time.
The plan relies on the following features in APT:
- Guiding control (PhD).
- Plate solving (whichever way is defined).
Note that APTPG doesn't get realtime feedback from APT. That means that if you encounter problems with say, your guiding, your plan could get out of sync with the schedule and therefore no longer match what is possible (e.g. the targets might no longer be visible when you reach that stage in the plan). There is unfortunately nothing APTPG can do about that. The only way to mitigate the issue is not to fill the plan too tightly.
Keep in mind that APTPG is a Beta version and will contain issues. Please report them so that they can be fixed quickly. Feel free to also send suggestions.
(1) The end of the night is defined by default as 1 hour before sunrise. This is a personal preference and is partially season dependent. You can change that value in the file "SupernovaPlanGenerator.exe.config", option Dawn (in seconds).
(2) If you use a digital camera, you can set the ISO and quality in the file "SupernovaPlanGenerator.exe.config" with options "ISO" and "Quality".
(3) All times are considered local time.