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I particularly like it when, at work, other members of staff tell me my code isn’t written in the Python style and dismiss working, structured, debugged and documented code as somehow flawed.
I have twice had to demonstrate that doing image processing without using a linked list is generally faster and uses a lot less memory: which makes a big difference when you have a runtime greater than a few minutes.
I was forced to use Python at work after IDL licences were deemed too expensive and Matlab was clearly next on the chopping block. The libraries it has are great. The language itself, sucks.
It won’t be elegant or finished for a few days – I’m bug hunting at the moment – but it will be a single self contained file (probably 1800 lines or so). Mainly uses standard stuff like numpy. I’m running it under Anaconda.
May be able to improve the speed and memory usage yet. As far as possible I’m avoiding the temptation to resample images using splines or similar when I translate them to try to avoid the blurring/smearing that causes and maximise pixel counts. Happily, with well set up mounts the rotation isnt much. I’m doing integer shifts and translates where I can.
Python does gobble the memory though – havent checked yet but its probably converted the images to floating point or 64bit ints or something silly.
I got bored last night and so had a quick go at implementing a barebones blind stacking process that was totally self contained and and didnt use GPUs (not an area of programming I have ever had cause to venture into). To keep it simple I used Python3. It was able to stack a 60x 1Mpixel image set on a given drift/rotation rate in about 5-6seconds. So if you are wanting thousands of them, be prepared to wait thousands of seconds.
If you’ve a spare desktop knocking about then you can just start it running and come back in a few hours. Not a big deal.
Tycho wins though on being: 1, fast 2, fully integrated 3, largely already debugged and tested.
I think Python is part of the Linux install these days isnt it, so you can have some fun.
Its not that hard to do, you just have to be willing to throw CPU at the problem and wait. 🙂
But looking more closely at the manual, its obvious the author has put in some considerable effort. So, I think I will have a rummage around and see if I have a compatible old GPU knocking about. Could be fun.
Its not exactly an expensive licence afterall.
This makes interesting reading…. someone has imaged it.
If anyone fancies having a look to see if the new/improved paint job on one of the Starlink satellite has had a good effect, then have a look at Starlink-1130. If its worked well, then we should see an obviously dimmer satellite in the train. TLEs are on Celestrak as “supplemental”.
Last year I was part of a team that did some work on debris in the GEO belt. Using the INT we were still spotting debris objects down to mag 20/21. It didnt look like the population was tailing off even then. But without being allocated time on a bigger scope its hard to know.
Well, as the satellites are not illuminated by the sun after twilight in the winter, the winter may become the best time for long exposure wide angle imaging. Mid-summer is going to be horrific if thousands of these things go up.
As I recall, one of the Musk sats has a new paintjob that is supposed to be lower albedo. Does it look obviously dimmer? Has anyone observed it yet? My best guess is that if they will have managed an attentuation of the order of 2-2.25 mags. So they will still be bright enough to ruin almost any telescopic image.
The ordure is really going to encounter the ventilation system when they start failing, attitude control is lost and the tumbling starts. Some of the flares are going to be impressive. But hey, its okay, someone will get rich on the back of this.
A supernova at that distance is going to be pretty bright. Are any wavelengths reaching us likely to cause problems?
Happy Christmas/Hannukah/Saturnalia/Yule/Solstice
Thats really worth knowing. I have previously steered clear of trying to solve images with severely trailed stars assuming it would say “Sorry guv, no stars in here”.
Stop Press: seems to depend on the aspect ratio of the trails. The longer a trail is compared to its width the less likely it is to solve. Still worth knowing that Astrometry.net can be quite tolerant.
I was wondering how you did that. In the earlier pictures the stars were starlike but images 9-11 contained significantly trailed stars. Is astrometry.net really that forgiving/tolerant or did you extract some positions manually as a text list?
Even if they push the albedo from (say) 70% to 10% thats only going to be 2 and a bit magnitudes, so you go from a 3rd mag satellite mucking up your images to a 5th mag. Great.
Given that even geosats mess up deep sky images (and they are normally 8th mag or fainter) I’m not seeing much benefit.
The problem is he has a business plan to make money. What is his incentive to stop?
If we said anything, I wonder what he would call us?
Ah, I see. A 20 min running average certainly helps.
Impressive. Noise level at the 8-10mmags level perhaps.
This seemed appropriately timed: https://www.xkcd.com/2202/
