Moon Phase Clarification

I would commonly image broadband targets with moon phase up to say 30%, with decent angular separation, and narrowband up to say 60%. In Rowlands most excellent blog post on constraints it is suggested that a maximum moon phase target constraint applies even with the moon down. That would make the maximum moon phase constraint unduly onerous on sequencers target selection I.e a full moon way below the horizon would mean no targets with maximum moon phase constraints would run.


I was thinking the same thing Chris. Seems it might be better to be able to ignore the moon phase constraint if the moon is below the horizon by a certain amount (could be user selectable).

Have also been thinking about what constraints I would use in relation to moon phase and separation for broadband and narrowband, so was interested in what you were using and would be good to hear what others are doing also. Obviously depends on many factors - target brightness, filter bandwidth etc.


I had my first run of Sequencer in Advanced yesterday and I think the above is exactly what happened to me. By selecting Moon Down and Max Phase 35% for L imaging, most of my early evening targets were being ignored - even though the Moon was below the horizon BUT its phase was 36%. I only had a couple of hours of clear(ish) skies last night. I’ll try again today with less restrictive conditions.


The constraints are all in AND logic … so if you put moon down and moon phase also if the moon is down the phase might not match the constraints.

We have the moon avoidance constraints (a new one in addition) that will put in or the moon conditions with a correlated formula on development.

So be care about the constraints to avoid reject result.

All the best

Some sort of correlated formula that takes into account whether the moon is up, the phase and the distance from target would be great. I assume you are saying something like if 25% moon and 60 degree separation ok to image or 50% moon and 90 degree separation ok to image. (As a simple example).

With the current constraints is it feasible to have the option of moon down and moon phase as OR logic? For example if moon is down or moon phase less than 25% ok to image. Not sure if this is difficult to do with your model or not.


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Its possible Leigh, this is something I find useful during my personal test and I put in the todo list
But now I’m interested in see engine running, so priority now is on the robotarget manager