"Copy Target Settings To..." Does Not Adjust End Time

Sequence Generator Sequencing
1

I have a sequence of asteroids that I want to track during the night. I want to make sure they are all above a certain altitude when tracked. These are all imported automatically using C2A to generate the list and SGP to import them using Starry Skies format. I import the list three times to get three time-separated observations of each asteroid during the night. Time/altitude constraints are not imported.

Start time does not concern me so much as I can start the sequence appropriately using the first target but I was hoping to use SGP’s Target Settings to automatically set the end time for each object corresponding to, say, 30 degrees altitude by using the copy functions that are available by right-click on the target cog-icon.

If I generate the first target settings by typing in the end altitude, it works fine for that object. Then if I copy the first target settings to all other objects, I get exactly the same values for all. Perfectly understandable as the constraint is not checked and the altitude is not locked. If I check the first target end constraint and copy the settings, the time constraint is used and the altitude is adjusted accordingly for the other targets. Also perfectly understandable. If, however, I check the end target constraint and lock the altitude (or use the planning tool) then copy the settings, the other targets get the altitude limit as expected but the time is incorrect and doesn’t appear to relate to the altitude in any way. I was expecting the end time to be correct for the given altitude. Am I missing something? I am ignoring some small round-off errors that appear in the altitude.

Since I might have 75 or so separate targets, it is onerous to manually set a stop altitude/time for each. BTW, an issue related to entry errors with multiple targets of the same name is here:

Capability for Multiple Runs on Same Targets

I am using Version 3.1.0.544

2

This feature was added prior to altitude constraints. Under the hood, SGPro is not aware of and does not care about altitude constraints. When target settings are copied, only the times are ever copied to the receiving targets and altitude is derived as needed during sequence execution. I’ll need to think about a way to essentially “fake” the copy of data that does not exist to another target based on that target’s constraint config.

Are you able to embed time constraints in the import data?

3

SGP seems to do the “right” thing when I copy the time constraints without locking. That is, at the time I do the copy, it adjusts the altitude in the constraint window properly to match the time. It you’re doing that, can you not also do the inverse, i.e. adjust the time to properly match the altitude when locked? If you don’t do that, there might be a surprising end to the night for some future unsuspecting user who does a locked copy. You just have to get the HA from the LST - RA, and use a little spherical trig with that and the DEC, LST and latitude to get the altitude. But you probably know all that.

I would have to talk to Philippe Deverchere (C2A author) to see if he might want to add Time/Altitude constraints. He already made the import from his program possible by setting up a minimal Starry Night output capability for me. Having an automatic, proper end time is very useful to me as I now have to manually guarantee that I’m not going to hit the floor with my 18" behemoth.

Really like your program and thanks,
Kent