Process help - deciding how to best sequence multiple targets over several months
I have chosen a set of imaging targets I would like to do over the next 3-6 months weather permitting. I am wondering if there is a range of cooperating software that will let me execute a multiple night multiple plan that can select targets based upon their promixity to an ideal elevation in the sky at any given moment and the completeness of my desired imaging plans?
So broadly I need to:
decide how much data to get on each target over a multiple months and
plan how best to allocate imaging time each available night to objects in the target list based on how favourably they are positioned and hom much data I have collected and am yet to collect on each and
automate as much of possible of each nights' subsequent imaging plan - by importing the nights play list into APT / SGP and being able to track my achieved data gathering process for these targets over many nights.
I expect N.I.N.A. can do large parts of this - but before I learn that I normally use APT and SGP to execute single night plans on 3-5 targets a night.
What I want to do now is plan how I will collect data on 20 NGC targets over the next 3-6 months.
Can any folk give me pointers on software and workflows to help progress the 3 points above.
I see re point 2 above N.I.N.A. now has a plug in as of a few weeks ago that is targeteding to do exactly that - raised the idea to Ivo from APT to see if he could leverage the same.
To help me plan my imaging plans I am coding a very small simple Excel spreadsheet - for OSC and then I will add Mono LRGB and L Ha SII OIII planning templates. I keep imaging runnings to sets of 30 minutes initially to simplify everything planning wise.
Many thanks - I certainly will! I just went through Telescopius and reviewed 3,000 targets to find 75 I think I will place on my to do list - enough to keep me busy for quite some time.
The think I didn't cotton on to at first is most of my targets are beween Magnitudes 9 to 12 - so I should adjust my imaging plans with greater sensitivity in regards to the targets I am after!
Just looked at Voyager Advanced - seems more into the sequence execution and control versus target planning and exposure optimisation.
Certainly powerful but not cheap - and I guess it competes against Freeware N.I.N.A. with its freeware Sequence selection and Target execution alah the latest plug-in by Tom Palmer that looks really advanced
It would really help me if you give me a screen shot of what it can suggest on say a pretty standard target at random I pick NGC 1672 in Dorado. So what exposure plans would it recommend for Bortle 6 skies with no Moon for a magnitude 9.8 target for my three gear combinations:
Actually Voyager advanced is pretty much all about target planning and prioritisation.
I really wrote war and peace here but without looking at advanced directly, it would not make much sense. To put it simply, you can set up as many targets as you want, with various constraints about hour angle limits, moon phase and distance etc and many others, and just let it go. One of the best bits I find is having it split time between narrowband and broadband on the same target. You set the target up twice (Which is quick and easy to do) one with broadband and one with narrowband filters to shoot, and with the target constraints set up properly it will on a third quarter moon for instance, start the night shooting RGB and when the moon rises it will change to narrowband. Similarly you can limit what hour angles it shoots the target within, so if you want to only shoot two hours either side of the meridian that is easy to set up and it will only shoot those angles then move on to another target that qualifies if you have set up another that does. I have had it shoot data on four successive targets in a night before.
So I am going to look more into Voyager Advanced - but so far I didn't hear you confirm:
1. Can it help you plan an individual imaging run - how to best allocate time for a OSC or Mono + LRGB or Mono + Ha SII OIII - and it was the imagining run allocation so N x lots of what mix of time per filter per target magnitidue versus local sky conditions and refractor size
and
2. Does it offer any more that N.I.N.A. freeware scheduler and dispatcher linked above. From the sounds of it Voyager Advanced offers exactly the same as freeware N.I.N.A. plug in.
Can you clarify your understanding of those two points please!
I am not 100% sure what you mean by planning an individual run.
In terms of splitting time between NB and broadband I let the moon constraints do the work. I generally try to shoot quite a bit of LRGB on targets, so for instance I set a "Moon up" constraint on my narrowband sets, so if the moon is down, it will shoot LRGB exclusively (Which I have often set up with a "Moon down" constraint though I am now playing with the moon Lorentzian constraints, which set a moon distance based on the phase, and have three sets, so I use an LRGB, a narrowband and a seperate Oiii onbe that falls between the other two given Oiii tends to be more sensitive to the moon that HA or Sii.
That way for instance if you are under a first quarter moon, it will shoot narrowband until the moon sets then change to LRGB. And under a three quarter moon the opposite happens, it shoots LRGB until moonrise then changes to narrowband, and you do not need to mess around night by night working out what time to shoot NB versus LRGB, the moon constraints do it for you.
I tend to throw multiple targets at it (With the slight pain of planning targets to suit a single camera angle as I don't have a rotator) with the targets planned to pass through the meridian a few hours apart. With hour angle constraints to shoot maybe two hours either side of the meridian per target, if you are setting up and tearing down each night you might widen that window to get as much data as you can on a target per night but I try to stay not more than + - 3 hours. Mid winter I have had it shoot data on three targets in a night.
In my experience Voyager nails focus time after time, better than anything else I have used, and it does it quickly. A single star focus (Robostar in Voyager terms) takes about the same time as full frame focus (Localfield) even including the slews, and NB focus via Robostar takes about the same amount of time as LRGB does as it slews to brighter stars so the exposure time is about the same.
And then there is the error detection and actions. I help a friend with a bit of a temperamental camera, the driver or firmware occasionally mess up and with every other software package he had used it would be the end of his night unless he was up and saw it. It required the cam to be power cycled and USB connection cycled to revive it. I helped with a dragscript (Which is a drag and drop method of setting Voyager up to work as you want it) so that on the camera throwing an expose error it will stop the mount, close PHD2 (Which sometimes didn't behave itself afterwards) then via "Viking" (Another bit of software by the same developer, to control interface equipment) disconnect the setup, power and USB cycle the camera via his Powerbox Ultimate, reconnect the setup (Which will re-launch PHD2) cool the cam and keep on going, emailing us when it does so. I have seen it revive the camera three or four times in a night before. You still loose time to it (Cooling the cam particularly) but not nearly so much as the cam lockig up just after you go to bed.
I can't compare Voyager to NINA as I went to Voyager when NINA was in it's infancy and at that time it was not able to do what I wanted but notwithstanding that Voyager is a subscription model I can't see any reason I would change, for me it just works too well at integrating everything. For those that want to there is also a version that can control an array, so you can have up to four scopes on a single mount, shooting different cub lengths and it will coordinate the exposures, focus runs etc, and make sure you don't do something like have it dither the mount while one of the cams is still exposing.
Thanks for that detailed description - and it makes sense!
For me I break the night up into 30 minute time chunks and then allocate them to targets that meet my critieria. So say NGC 300 is in a position I like and I allocate 6 x 30 minute blocks of time to data capture.
Within each 30 minute mini plan then I split time across my filters and subs lengths - dependedent on Moon size and proximity - whether the target has High Dynamic range (e.g. M42) or not - whether I am using One Shot colour or LRGB or Narrow band and my skies, my gear and the targe lumonsity.
What I was curious to know was can Voyager take in thos parameters and advise how long to make my subs - not how much time to give to any one target (which I think of as scheduling and dispatching imaging plans) - an important but separate topic of conversation.
So as a guide I created my time allocation strategy per 30 minute time slots - I was wondering how in a 30 minute window Voyager would advise me I allocate my time to OSC, LRGB or Narrowband on say NGC 300?
So my 30 minute time allocation strategy so far was in the image above - I am asking can Voyager do much better?
Hmmm, I did war and peace again and deleted it after reading your post one more time as it really wouldn't answer your questions.
First up, Voyager won't do planning for you in terms of suggesting sub lengths per target, I don't know what software does that? I find my ideal sub lengths empirically by test shots on target, sticking to regular lengths (I.E. 30-60-120-24-300 seconds) shooting more than one length if required for really high dynamic range targets like M42. One length giving around 1000 saturated pixels per sub, and a longer one for the faint stuff. Normal targets I will just pick the approx 1000 saturated pixels and go.
Regards the 30 minute block time allocation strategy. I would not necessarily call it "Better" as that is subjective, but Voyager Advanced is going to do it very differently. It sounds like you are breaking up your 30 minute chunks to shoot different filters based on target location and moon distance (Dependant on phase)
To tackle moon distance and phase first, that is covered by the moon avoidance Lorentzian constraints (And why I create LRGB/HA-Sii and Oiii versions of the target, to make use of different Lorentzian settings) and you can be more explicit and set up discrete "Moon down" and "Moon up" constraints to force LRGB only when the moon is down, and NB only when it is up.
As to position of the target, the constraints you set per target do that for you, though it will probably be the same in terms of hour angles target after target. I prefer hour angle to altitude given it is constant regardless of declination but if you have an unfavourable horizon to the south east as an example you can use a custom horizon so that if a target would fall into your hour angle constraint but be blocked by a building or other obstruction, it won't be shot until it clears it.
The Voyager advanced way is rather than trying to actively schedule the imaging run in discrete blocks night by night, just set up your constraints, set how many subs per filter and how many repeats then set it going.
Appreciate your thoughts - yes I am not aware of any software that helps you determine optimal sub lengths per target and filter combination.
My allocate time in 30 minute blocks was just to make it far simpler when I want to switch targets imaging on two scopes if every target's plan is just a variation of a group of subs totalling 30 minutes per cycle - it makes target swapping simpler.
So give I have about 75 targets I wish to image - you guessed it I have 150 imaging plans and all look cohesively similar - so I would guess its likely not optimially set up.
I am rather curious by of your technique comment "One length giving around 1000 saturated pixels per sub" - how do you measure it and why do you choose it?
I presume you are saying in a camera with maybe 20 million pixels you desire around 1,000 pixels to have a full light well - do I have that correct?
Very interesting proposition - so only a fraction of total pixels - and those for the bright points in your subs are totally exposed - but how do you measure it?
I use APT and SGP to control imaging - and perform a low stretch on my subs when they are displayed.
So if I look at a 300 second shot of NGC 300 through my 132mm refractor into a ZWO blue filter into a 1600MM-c I see the following histogram - stretched which doesn't look like many pixels are at all near saturation - must check if I am reading that correctly!
What are you using to determine how many pixels are saturated - Voyager again?
I assume if you have 74 targets that you want to image, they are of varying RA and will come into good positions throughout the year? That being the case you could in theory set up all of them at once in the Robotarget manager and they will be done in turn as they pass through the hour angle constraints that are normal to set. I have to look into it more as I have not used it so far but there is a "West preferred" setting for Robotarget, meaning that if you have two targets which qualify and which have the same scheduler priority set, Voyager will pick the most westerly one first.
As for picking my 1000 of so saturated pixels. My reason for choosing that is to make sure as few stars or bright objects as possible are saturated to white, to preserve star colours if I can.
There is an image viewer packaged with Voyager which shows some basic image statistics, such as minimum pixel value (And how many pixels are at it) Mean, median and maximum value (Normally that will be saturated, and how many pixels are at that value, which is where I pull that figure from)
It may get a bit subjective, I recently had to accept a lot more saturated pixels than I normally would due to bright stars near a dim target.
As it happens, in my case a typical LRGB cycle takes about 40 minutes as 120 second exposures seem to work pretty well, but when you can let the scheduler do the work it does not matter too much, if the target passes out of the hour angle limit or fails some other constraint it finishes the running sub and moves on to the next target.
