By Asatron on Friday, 24 December 2021
Posted in Syndicate Lounge
Replies 6
Likes 0
Views 691
Votes 0
just so all the member know, most of the jobs put in recently have had "Moon down' in the notes section, this means it has very little to do all month with the moon up and will sit idle most nights as the moon is down for only so many days a month. As I have said before, its your pier to do as you wish, so that's fine with us if you want to do all images moon down I am just making you aware is all Steve
Steve, When I started out on this pier I received some data completely comprised by strong moonlight. I believe that you advised I needed to put some moonlight restrictions in the comments box. Now I don't really know how the scheduling software works e.g. what weights to the various observing conditions; cloud, zd, moon phase etc., is it fully automated or is there some human intervention? Without this detailed knowledge, I have tended to err on the conservative side by requesting moon down or < 25%.    My thinking is as follows.  This is an OSC camera, and most DSO imaging will be impacted by the moon.  An image is only as good as its weakest band - for am OSC thesis the B filter in the Bayer matrix.  As a professional, I always used the dictum that the time to call it quits with sky brightness was when the sky counts were doubled over a dark sky.  For B band this occurs at roughly Day 5 moon, or around 25%. Hence framing my request as moon down or < 25%.  If we were to use this approach, then 10 nights per lunation fulfil that criterion and a further 8 or so nights still have moon down for an average 50% of time - giving approximately 14nights per lunation - approximately half the time.   I am not sure this is what you mean by "only so many days per month", but it doesn't look to back to me. Ideally it would be helpful to frame the request as "please only take the image when the sky brightness is fainter than 21mag/arcsec", but again I am not sure if the scheduling software has the ability to interpret this.   So, in the absence of better information, my request will still request moon down or
·
2 years ago
·
0 Likes
·
0 Votes
·
0 Comments
·
Steve, When I started out on this pier I received some data completely comprised by strong moonlight. I believe that you advised I needed to put some moonlight restrictions in the comments box. Now I don't really know how the scheduling software works e.g. what weights to the various observing conditions; cloud, zd, moon phase etc., is it fully automated or is there some human intervention? Without this detailed knowledge, I have tended to err on the conservative side by requesting moon down or < 25%.    My thinking is as follows.  This is an OSC camera, and most DSO imaging will be impacted by the moon.  An image is only as good as its weakest band - for am OSC thesis the B filter in the Bayer matrix.  As a professional, I always used the dictum that the time to call it quits with sky brightness was when the sky counts were doubled over a dark sky.  For B band this occurs at roughly Day 5 moon, or around 25%. Hence framing my request as moon down or < 25%.  If we were to use this approach, then 10 nights per lunation fulfil that criterion and a further 8 or so nights still have moon down for an average 50% of time - giving approximately 14nights per lunation - approximately half the time.   I am not sure this is what you mean by "only so many days per month", but it doesn't look to back to me. Ideally it would be helpful to frame the request as "please only take the image when the sky brightness is fainter than 21mag/arcsec", but again I am not sure if the scheduling software has the ability to interpret this.   So, in the absence of better information, my request will still request moon down or
·
2 years ago
·
0 Likes
·
0 Votes
·
0 Comments
·
Merry Xmas Brian Yeah, moon down for some dim objects in conjunction with other normal objects being used with standard moon avoidance parameters can be a very productive way of using the pier I was just letting members know in case they were unaware the vast majority seem to be moon down of late and this could impact data collection, especially during unsettled weather periods that may fall over new moon for instance. This could mean little data collection PS the automated moon avoidance parameters are at the top of the lounge as a sticky . We cannot do specials like
·
2 years ago
·
0 Likes
·
0 Votes
·
0 Comments
·
Hi Steve, And a Happy New Year to you! I was aware of that sticky note, but I  must admit to being somewhat skeptical of those moon avoidance settings.  It has been my experience that, as soon as a bright moon (e.g. more than 7 days old) is in the sky, most of the sky is flooded with ilight, irrespective of distance from the moon.  However, that s only my experience,  coupled with a few scientific papers on night-sky brightness at certain locations. Nevertheless, I am sure that these curves must be based on empirical or modelled data based on the Roboscopes site.  Given that some thought/modeeling must have gone into these curves, what max increase in sky brightness do these curves actually correspond to?  Also I was a little confused by the "120 & 5" condition applied to each avoidance settings.  I get the 120deg min separation at full moon, but wasn't sure what the &5 refrerred to (also the width 5) bar on each chart.  Also what it the yellow line on each chart?  I wasn't aware that the system couldn't interpret
·
2 years ago
·
0 Likes
·
0 Votes
·
0 Comments
·
Hi Steve, And a Happy New Year to you! I was aware of that sticky note, but I  must admit to being somewhat skeptical of those moon avoidance settings.  It has been my experience that, as soon as a bright moon (e.g. more than 7 days old) is in the sky, most of the sky is flooded with ilight, irrespective of distance from the moon.  However, that s only my experience,  coupled with a few scientific papers on night-sky brightness at certain locations. Nevertheless, I am sure that these curves must be based on empirical or modelled data based on the Roboscopes site.  Given that some thought/modeeling must have gone into these curves, what max increase in sky brightness do these curves actually correspond to?  Also I was a little confused by the "120 & 5" condition applied to each avoidance settings.  I get the 120deg min separation at full moon, but wasn't sure what the &5 refrerred to (also the width 5) bar on each chart.  Also what it the yellow line on each chart?  I wasn't aware that the system couldn't interpret
·
2 years ago
·
0 Likes
·
0 Votes
·
0 Comments
·
Thanks Steve. The penny has finally dropped. You are using the BAIT moon avoidance function. That explains a lot. i am glad it works for you. 
·
2 years ago
·
0 Likes
·
0 Votes
·
0 Comments
·
View Full Post