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  #1  
Old 27-12-2017, 03:30 PM
g3n1u5 (Tony)
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Talking Analogue Computer and Spectrosocpy

Good Afternoon,

I have noticed a resurgence in Analogue computing, and there seems to be strong ties with Spectroscopy. I have a Star Analyser 100, and a bunch of different pass through filters, etc.

I am interested in communicating with other people who are interested in breaking down the light into meaningful data.

Regards
Tony Nolan
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  #2  
Old 27-12-2017, 04:01 PM
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Merlin66 (Ken)
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Tony,
I’ve been actively involved in most aspects of spectroscopy for over ten years - even published a few books on the subject....
I’m not sure what you have come across Re Analogue computing but would certainly be interested in following up.
Using a Star Analyser is a great starting point - I call it “Spectroscopy 101”.
We have developed many very effective processing processing software solutions which have had a significant impact on the amateur community.
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  #3  
Old 28-12-2017, 08:29 AM
g3n1u5 (Tony)
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Thanks

Good Morning Ken,

Thanks for your reply.

There is starting to be a move away from binary coputing ie 0 & 1, to analogue computing like fuzzy logic 0 - .99 for example. There are some interesting ways to use cameras, and break down the light into its RGB components, and then assign a number of digital fingerprint to that specific combination. Then you can do soem interesting maths with them, in optical calculations, etc.

I am interested in how I can get readings from the stars, and see the differences between them. I am interested in seeing if you can identift a star from its spectrum, rather than its position ?

Regards
Tony
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  #4  
Old 28-12-2017, 08:42 AM
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Merlin66 (Ken)
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Tony,
I think I understand...
Using filters - RGB, Photometric or Narrowband to separate different sections of the star spectrum is not uncommon, and can be used determine stellar magnitudes.
Unfortunately to positively identify a unique star is almost impossible even from a high resolution spectrum. The best we could probably do would be to say it's a G2v type star......and there are thousands of those ;-)
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  #5  
Old 28-12-2017, 08:49 AM
rally
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Hi Tony,

Can you provide some links to this information so we can read about it please.

Thanks

Rally
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  #6  
Old 28-12-2017, 12:45 PM
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Ken,
Not to hijack the thread but could you please link to your books. As I built a few spectrometers of differing designs recently. It would be good to see a “been there, done that perspective”
Kind Regards,

Trent
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  #7  
Old 28-12-2017, 01:08 PM
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Merlin66 (Ken)
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Trent,
"Astronomical Spectroscopy for Amateurs"
https://www.amazon.com.au/Astronomic...+spectroscopes
Covers some history, spectroscope design, commercial spectrographs and software as well as construction details for a DIY instruments.

"Grating Spectroscopes - How to use"
https://www.amazon.com.au/Grating-Sp...+spectroscopes

Primarily for users of the Star Analyser/ Rainbow Optics gratings. How to set them up and process/ analyse the spectra.

"Imaging Sunlight - Using a digital spectroheliograph"
https://www.amazon.com.au/Imaging-Su...aging+sunlight

Background history and details of solar phenomena - photosphere and chromosphere. Solar filter design and commercial solar filters. Applying hi resolution spectroscopes to obtain AVI files of the solar spectrum, converting these to a very narrowband solar image. Examples of many SHG built around the world.

Hope this helps,
Ken
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  #8  
Old 28-12-2017, 02:14 PM
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Thank you.
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  #9  
Old 28-12-2017, 02:29 PM
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Merlin66 (Ken)
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Trent,
On our webpage you will find some great links - I must give honorable mention to Christian Buil's excellent resource material....well worth the visit.
http://www.astronomicalspectroscopy.com/reference.html
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  #10  
Old 28-12-2017, 02:47 PM
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sheeny (Al)
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Having used real analogue computers at uni, you had me intrigued...

FWIW I don't think fuzzy logic in a digital computer qualifies as "analog". I don't mean to crash your thread, so I'm just offering the following FYI so everyone is on the same page. I was expecting Op amps and feed back and feed forward loops, etc .

https://en.wikipedia.org/wiki/Analog_computer

That's OK, fuzzy logic is cool too.

Having done a bit of spectroscopy, I'd be interested to see how fuzzy logic applies. The existing digital processing tools seem pretty adequate to me, so you've got me intrigued how fuzzy logic would add something to the mix.

Pass the pop corn...

Al.
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  #11  
Old 29-12-2017, 02:04 AM
robin_astro
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Machine learning techniques have been applied quite extensively to the automation of classification of astronomical objects from their spectra eg
https://arxiv.org/pdf/1609.03147.pdf

Robin
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  #12  
Old 29-12-2017, 07:16 AM
g3n1u5 (Tony)
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Analogue websites

Hi Rally,

there are a few articles on the web, and in the IEEE mags. I will be making a webpage with a list of them very soon.

Regards
Tony
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  #13  
Old 29-12-2017, 07:39 AM
g3n1u5 (Tony)
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fuzzy (Analogue) vs crisp (binary)

The group / focus I come from, believe that digital computing is dead, and was a cheap and easy branch of technology, but now its showing it cant cope with what is required.

Jack Ma, the guy that owns Alibaba has been saying for a while now, that almost all artificial intelligence work is down the wrong track, and that platforms could be to blame.

So when you apply fuzzy logic and digital hashes to optical calculations using light, in a single 10th of a second photon pulse, you can transmit a number between 0 and 16.7m. A practical application, is to have 3 analogue sensors which produce a colour, which is transmitted to a sensor that breaks down the colour and controls a systemic response. So lets say for example, you have a humidly, temp, and wind speed. The combination of them produces one of 16.7m different colours, and the reciever is programed to turn on and off watering systems when a range of colours appear. And this process is at the speed of under a second, etc

By applying fuzzy to a value, rather than 1s and 0s, speeds up the whole operation.

The app, i have in final stages of development, can read light transmissions, do calculations between 0 and 240 trillion, map sound and motion patterns. Especially with horse or muscle memory, and it can encrypt messages in jpgs, that can be transmitted.

So i can write a computer program in english, transform it into colour using my hash, and then send that jpg to some one, and they can decode it, save the program, and it will run.

But that is just where we are at now, and there is more play time ahead.

But I am really interested in the Spectroscopy side of it, which is what took me down this inventing path in the first place. But i do have to confess, I am not only interested in stars, but also in the viewing of objects in normal sun light also. So i have turned my lens/filter onto trees, metals, buildings, people, etc.... to try and better understand the variations.

But now I want to focus on stars, and better understand how to use it. Im on ASNSW, and i heard there was a special interest group in this, but i tried to make contact several times, but never ever got any replies. So here i am, hoping that others might have an interest like mine.
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  #14  
Old 29-12-2017, 07:58 AM
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Merlin66 (Ken)
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Executive summary of the 17 page paper referenced by Robin:

Spectra of 100,000 stars was used to train a computer to recognise the spectral classes (OBAFGKM etc) using three different algorithms (PNN, SVN and K-means).
These algorithms were then used to identify a batch of 300,000 spectra.

It was necessary to use 700 data points on the spectrum between 3850 and 8900A.
These algorithms have been able to correctly classify approximately 80% of the data set.
It took between 23 and 29hr computing time to do the analysis.
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  #15  
Old 29-12-2017, 08:39 AM
g3n1u5 (Tony)
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one link

https://spectrum.ieee.org/computing/...m_medium=email
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  #16  
Old 30-12-2017, 06:49 AM
g3n1u5 (Tony)
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Software

Good Morning,

Is there software, that can be used with a cam and filter please?

Regards
Tony
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  #17  
Old 30-12-2017, 07:03 AM
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Merlin66 (Ken)
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I've detailed most of the available software on the website.
I use and recommend BASS Project.
http://www.astronomicalspectroscopy.com/process.html
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