Request to specify target start and end by altitude

Right now I can specify my target end time, but as I image a target over several nights (or weeks or months) the time that the target goes behind the trees changes, so I have to keep updating the end time manually.

It would be great if I could give the altitude of the target where it hits the trees and let SGP end the target based on that.

Same applies for target start.



Nice idea. I would guess this would not be super hard as it is really just a calculator of sorts.

Andy - we’re thinking along similar lines again. I suggested that too on 28Dec. Jared responded it was on his backlog and he’ll get to it sometime.

Agreed. It’d be nice to define the horizon locally (preferably using an app on your phone so you could ‘draw’ the horizon from inside your obs, I’d totally pay about 5-10 bucks for that feature) and then determine if the object is approaching your defined horizon and moved on to the next event as if it hit a time limit.

1 Like

Not guaranteeing an implementation identical to those described above, but this is definitely on the 2.5 list.

thirding or maybe fourthing this. i have a ridiculously small window to image thru at home (like 2h of RA) and it would be nice to just make horizon constraints and have SGP compute when to run each target in the list.

1 Like

Agreed. It would be nice for multiple night runs so you didn’t have to change the stop time.

+1 I could have used this last night!

Another +1 for this feature. WHen I was using CCD Commander I found this to
be very useful.

Plus on this one too, I fortunately can’t go under +30° on all size because of my roll-off walls

1 Like

Plus another one - I’m only using start and stop times as a means to determine when a target is above the murk and thus imagable. One way would be to use Alt-Az limits but this is too restrictive for me, I would much prefer + and - RA angle setable independently for each target. Doing it this way would mean I could just start a sequence at any time with multiple objects and have them cycle through whatever the date.

This could also be implemented as a selectable horizon chart a la TheSkyX for example which allows the horizon to be drawn with a mouse.

If this is going to be implemented in some way then the targets may need a priority to ensure the most important get first choice where target imaging times overlap.

Just my two-penneth.


Not having to hard code the start - stop times for a target is a useful option. Using a minimum altitude above the horizon to start and / or stop the imaging sequence would be a good way to do this. However, I believe the situation is a bit more complicated in that imaging equipment considerations could add to the start / stop time restrictions.

Let’s say I don’t want to ever do a meridian flip during imaging. Then, in addition to target altitude, I want an additional limit of “don’t start until meridian -3 hours (east)” and “stop at meridian +1 hour (west).”

With a sequence setup with three properly selected targets, I can get a full night of automated imaging with no flips. This sequence can be run on multiple nights without making any changes – even if those nights span multiple months.

This approach means the list of targets is scanned at sequence start to pick the “best target” to image. This criteria is simple – the target selected is the one closest to its ending time. When that target is ended, the remaining targets are scanned with the same criteria and the second target is selected. When no target has anything to do, the sequence is ended.

It seems to me that both the altitude restriction and meridian restriction are actually global parameters and not specific to a selected target. So the altitude limits and meridian limits would be setup in the equipment profile. Then when a target is created, there would be the normal start / stop times available or the imager could select “Use Global Limits” and the automated target start stop times would be calculated at sequence start.


CCD Autopilot displays the objects time crossing at the meridian and at 45 degree altitude ( I think you could can this to 30 degrees etc).

Also, the program shows astronomical twilight start/end and moon rise/ set. This is a feature I miss.
I hope SGP adds something like it.


An “imaging mission” is two part – the planning phase and the execution phase. SGP is all about execution and I like that. I personally think planning should be off loaded to other tools.


I have to disagree. If you are going to have SGP stop 30 degrees above horizon. Then you have crossed over to planning in anyway.

Besides if you spent the extra money on the mosiac wizard you already have a planning feature. There are certainly planners and schedulers that will do this and more.


We are probably caught up in semantics in defining execution -vs- planning. If you want just one target to stop at 30 degrees above the horizon that might be considered planning. If you want all your imaging to stop at 30 degrees above the horizon that would seem to be an execution constraint…

By the time you get to using the FMW, you have already planned and selected a target. The FMW allows you to specify your execution strategy by selecting the number and orientation of the panels. Clearly that could also be considered as planning.

To me, planning is when I sit down in front of my computer in February and start hunting for three or four targets that will be well positioned to image in April. The “visual guys” have a lot of help from products like Deep Sky Planner, Astro Planner and others. While these products can be used for planning an imaging run (I personally use both), the special needs of imaging planning don’t seem to be well supported at this time.


+1 for the request to be able to start and stop by altitude. Astroplanner has a fantastic horizon mapping function and so there is truth in the comments about planning.

However once you have a multi-object run set up to run from suburbia, its amazing how many days and weeks can go by in between clear nights/work/family etc. Could be SO helpful to have altitude start/stop options for each target rather than having to tweak start/stop times manually every week or so.

Nothing more frustrating than missing out on a few key filter frames when getting close to finishing an object. In a worse case, you may end up shelving a project until the follow year, so these minutes really are precious. I had started a request thread some time ago suggested local sidereal time could be useful, but inclined to agree object altitude is a simpler concept to run with.

1 Like

Any new developments on this front? Any chance start and stop imaging by altitude is still on the wish list?

Yes, it is absolutely still on the to do list. With limited time and necessary (vs nice to have) items that are in front of it, we cannot commit to a timeline.

Thanks Ken. You guys work miracles as it is, so glad to hear its still possible at some future time.