DIY Solar Scintillation Seeing Monitor with FC support

[PDB]

Hi,

I agree with GreatAttractor, it will probably make little difference recessing the sensor. Maybe you need to aim a little bit better for the Sun
(If you place a trimmer instead of the 220K resistor ove U1, you can adjust setting very easy)

I have added an Arduino sketch on my github ssMon pages (https://github.com/paul-db/ssMon )
Currently I am reworking the ssMon program, now only working on Linux, so that it will also run on Windows. There will also be an interface to Planetary Imager (already in the V.02.01 branch, but not officially released) and when I have time a connection to the newly released Linux version of FireCapture.

With regards,

Paul

[rsfoto]

Hi Paul,

Maybe you need to aim a little bit better for the Sun

I will try I asked as I thought it would be better to have it a bit protected. As written I will try to get a better aiming of my telescope to the Sun

Will take a look at your Arduino sketch. Does it run on an Arduino UNO ?

Thanks

[rsfoto]

Hi Paul,

Maybe you need to aim a little bit better for the Sun

I will try I asked as I thought it would be better to have it a bit protected. As written I will try to get a better aiming of my telescope to the Sun

Will take a look at your Arduino sketch. Does it run on an Arduino UNO ?

Thanks

Hi Paul,

Can not open the tar.gz file as I have Windows :-) Would you please make a zip file ? Thank you very much.

[PDB]

Now in ZIP format as well.

P.

[rsfoto]

Now in ZIP format as well.

P.

Hi Paul,

Thanks a lot.

[rsfoto]

Hi,

Well. Here it is and testing.

Does not look nice but seems to work. Did not get 20M Ohm resistor so I used 2x 10M Ohm and as well did not find a 3.3uF capacitor so I am used 3 1uF capacitors in Parallel.

I used a 500 Ohm Trimpot for adjusting the Sun intensity.

Some images

Set up sitting on a chairs back rest in order to get it close to my telescope.

IMG_2712_C1.jpg (422.18 KiB) Viewed 644 times

View of the front of the telescope with a white light solar film from Baader. Many years old The black box is the sensor of my Solar guider and the second image is the control box of my Solar guider.

IMG_2713_C1.jpg (454.5 KiB) Viewed 644 times

IMG_2719_C1.jpg (280.41 KiB) Viewed 644 times

Screen shot of the Laptop screen and the written values

IMG_2717_C1.jpg (345.18 KiB) Viewed 644 times

[rsfoto]

Hi,

Well I am in my Observatory, 420 km North of Mexico and Mr Murphy too



NO full sun shine, very high heavy clouds and can not calibrate it.

By the way, Does anybody have a graphic of how the values are when clouds are present ? Would be interesting for me to see how the Sun intensity is and the seeing value

Is it possible that with clouds the scintillation of the sun is less ?

This is my Sunshine at the moment

IMG_2720_C1.jpg (390.99 KiB) Viewed 594 times

[GreatAttractor]

Is it possible that with clouds the scintillation of the sun is less ?

I sometimes get high, thin clouds that don't interfere much with recording (judging visually by the raw video and by successful stacking). However, I'd think SSM output through the clouds is meaningless, as the brightness changes due to clouds will completely swamp and distort the scintillation caused by seeing.

[rsfoto]

Is it possible that with clouds the scintillation of the sun is less ?

I sometimes get high, thin clouds that don't interfere much with recording (judging visually by the raw video and by successful stacking). However, I'd think SSM output through the clouds is meaningless, as the brightness changes due to clouds will completely swamp and distort the scintillation caused by seeing.

Hi and thanks.

I guess the clouds act as a filter and dampen the scintillation of the sun. I continue chasing the sun and well nature is nature and hopefull some of these days I get a cloudless day

... distort the scintillation caused by seeing.

I think what you wrote there is a bit upside down. From what I know seeing is defined as quality of the sky and in this case the quality of the capability of seeing is the scintillation of the Sun eg. the less the Sun scintillates the better the seeing.

Seeing is a product of the scintillation of the Sun which is caused by air turbulence passing in front of the Light emitted by the Sun.

At least that is what I understand what seeing and scintillation is.

Happy festivities and regards

[rsfoto]

Hi,

Well, weather improved and I was able to play around with my SSM.

Had a few glitches which I have to observe but nothing deadly

It is interesting to observe in real time the images coming from my camera and compare it to the recorded values of the SSM. Afterwards when one processes the images one can corroborate that the image quality or at least the analysis AviStack presented in the diagrams are much in concordance with the values of the SSM.

So far I have not seen any wave tendency of the scintillation where I have my Observatory. At the moment I do not see a practical use for it apart from beeing a nice addition so one does not get bored while doing time lapses which take hours trying to get a flare or see something interesting.

Below some images of my setup and telescopes

IMG_2736_C1.jpg (938 KiB) Viewed 512 times

@ Paul, is the sensor well placed ?

IMG_2738_C1.jpg (1.04 MiB) Viewed 512 times

IMG_2740_C1_solarchat_a.jpg (263.12 KiB) Viewed 512 times

IMG_2742_C1.jpg (1.22 MiB) Viewed 512 times

IMG_2751_C1.jpg (1.5 MiB) Viewed 512 times

Below 2 graphs of the session of yesterday over on hour

RS-eeing_20171226_1h.JPG (203.45 KiB) Viewed 512 times

RS-eeing_20171226_1h_tendency.JPG (211.64 KiB) Viewed 512 times

and here the one hour video taken at 1260 mm focal length of Sun Spot 2692. I hope the next one is around the corner so I can continue with the tests and keep learning.

https://vimeo.com/248812555

Thanks for looking

[PDB]

Nice setup Rainer.
Seems you had decent seeing, which shows in the video as well.

Looking at the green graph some small clouds?
Maybe you also need to tune the intensity value. Sometimes it seems to go over 1 (if i read the graph correct)

Regards,

P.

[rsfoto]

Nice setup Rainer.
Seems you had decent seeing, which shows in the video as well.

Looking at the green graph some small clouds?
Maybe you also need to tune the intensity value. Sometimes it seems to go over 1 (if i read the graph correct)

Regards,

P.

Hi Paul,

Thank you. Yes and that is my problem. Today in the morning without having changed anything yesterday y started up everything and the RS-eeing Monitor was delivering values under 0.5 and even further down which was not logic for me as the sky is less cloudy then yesterday or could I be mistaken and the whole enchilada RS-eeing Monitor is working correct ?

Could the telephone cable be a problem ? I am using a 6 strand telephone cable and 3 of them are wired together so the resistance of the cable is more then low. Couls it be that is is an EMI = Eletromageetic Interference problem and should I go for a Coaxial cable ?

I just measured the 4m long cable and I have 2.8 Ohm on both triple strands.

The sensor is delivering about 2400uA ~ 2.4 mAmp at 0.5 Volt.

I think I will get a few meters of Coaxial cable and built a second sensor to see how it performs.

BTW now the Sun intensity is jumping around 1.0 and 0.7 ¿?

[PDB]

I use a coaxial cable with a length of 2.5 meter. I do notice some strange values sometimes but there I suspect some bad soldering on the cable ends. (I don't have a fixed setup and have to take scope, computer, cables out every time, reconnect everything, which is not good for the soldered connectors, have to redo these)
The fluctuations can be fairly high between days (transparancy of the air) and between seasons (air-mass?) I try to keep the input level between 0.5 and 0.9 . Unfortunately almost no sun in the last month(s) for testing, and the quark back to the US for repairs ....

P.

[rsfoto]

I use a coaxial cable with a length of 2.5 meter. I do notice some strange values sometimes but there I suspect some bad soldering on the cable ends. (I don't have a fixed setup and have to take scope, computer, cables out every time, reconnect everything, which is not good for the soldered connectors, have to redo these)
The fluctuations can be fairly high between days (transparency of the air) and between seasons (air-mass?) I try to keep the input level between 0.5 and 0.9 . Unfortunately almost no sun in the last month(s) for testing, and the quark back to the US for repairs ....

P.

Hi Paul,

Thanks. Will experiment and observe in the next days. While I am writing this very high thin clouds are passing so no chance to do a calibration which would make sense.

I just took out the arduino to the cold room in order to avoid the EMI of my 3 PC Monitors I have here.

[rsfoto]

Hi,

As usual Mr. Murphy is always there where he should not be



View to the South

South view

IMG_2762_C1.jpg (1.13 MiB) Viewed 500 times

and view to the North. As when you build a house they say to put the kitchen window to North as it is the most uniform light

North view

IMG_2763_C1.jpg (755.49 KiB) Viewed 500 times

[rsfoto]

Hi,

I have been having fun with the SSM.

Below a graph of measuring during 1.5 hours in order to see if there is a periodic wave form of the seeing which would allow us to plan imaging but I do not see any

So a SSM is a nice addition but so far not a big help for planning ...

RS-eeing_test_20171228_test_1.5h.JPG (181.52 KiB) Viewed 474 times

[GreatAttractor]

I like your results! Good correlation with the quality graph, so the device is working fine.

So a SSM is a nice addition but so far not a big help for planning ...

It seems to me that (apart from being a fun project) it's mainly useful for big-aperture people to trigger video recording during short moments of good seeing.

[rsfoto]

I like your results! Good correlation with the quality graph, so the device is working fine.

So a SSM is a nice addition but so far not a big help for planning ...

It seems to me that (apart from being a fun project) it's mainly useful for big-aperture people to trigger video recording during short moments of good seeing.

Hi,

Yes, could be. It is a question then of where to set the upper seeing limit as best quality measurement and a need for really fast cameras so it makes sense to trigger an acquisition.

I have been dealing with very high clouds all these days ...

I just finished building a second sensor and will test it.

IMG_2765_C1.jpg (795.32 KiB) Viewed 458 times

IMG_2766_C1.jpg (700.75 KiB) Viewed 458 times

[rsfoto]

I like your results! Good correlation with the quality graph, so the device is working fine.

So a SSM is a nice addition but so far not a big help for planning ...

It seems to me that (apart from being a fun project) it's mainly useful for big-aperture people to trigger video recording during short moments of good seeing.

Hi,

The above post made me think about how to decide what are good seeing values for the set up one has.

I guess it all depends of focal length and resolution per pixel. Am I correct in assuming that the less resolution ( more arcseconds per pixel) requires a better seeing the high resolution (less arcseconds per pixel) or is it the way around ?

¿ has anyone any info on how to correlate this ?

The original program takes 10000 measurements for one second values. ¿ has anybody tried to synchronize the seeing value to the speed of the camera ?

eg. My camera takes at an image size of 1632 x 1216 pixels 12 frames per second in average. So this could mean that if I go down and take 833 measurements the SSM would give me the seeing for each frame in my movie, more or less.

Will make some tests with this and then compare the SSM seeing graph with the graph AviStack delivers me about pixel movement. There should be then similar graphs. I suppose

Well I think I have found some use for the SSM.

The next step is to add a high speed ADC converter to the Arduino in order to have more values per iteration and frame. Have been looking at some yesterday.

Would a higher resolution then 10 bit give us an advantage ?

saludos

[rsfoto]

Hi,

I have a question in regard to the setting of the following offsets which I guess do affect the values of Sun Intensity and Seeing

...
IValueB=IValueB/Number+.0; // + or – small dc off-set
...
ValueB=ValueB-.05; // + or – small dc off-set
...

How can I determine the offset ?

Thanks and

[rsfoto]

Hi,

I have a question in regard to the setting of the following offsets which I guess do affect the values of Sun Intensity and Seeing

...
IValueB=IValueB/Number+.0; // + or – small dc off-set
...
ValueB=ValueB-.05; // + or – small dc off-set
...

How can I determine the offset ?

Thanks and

Hi,

Well after posting this message I read again the paper and the offset comes from the difference the voltage divider is delivering to pin 3 and pin 5.

I just measured the voltage there and my divider delivers 2.455 Volt and so I now added to the sketch the correction value of 0.045 in order to get the 2.500 V. In both cases I added it in the lines.

¿ was this correct ?

Sorry if this is becoming a monologue

[rsfoto]

Hi,

Interesting day today while playing around with the SSM. I think a seeing of about 0.14 ia a record here

Below some videos and graphs

900 mm focal length


https://vimeo.com/249199990

2017-12-30_12-44-14_graph.JPG (117.38 KiB) Viewed 437 times

1260 mm


https://vimeo.com/249200078

2017-12-30_12-49-17_graph.JPG (113.15 KiB) Viewed 437 times

1800 mm focal length which is more then the absolute limit for my setup using a 4x extender setup which gives me an f/21 and here I have to crank up the gain too much in order to have reasonable frames per second rates. I would say 1260 mm is more then enough for this.


https://vimeo.com/249200037

2017-12-30_12-56-17_graph.JPG (99.38 KiB) Viewed 437 times

The next move could be to use my TOA 130 but moving everything there is too much work

OK, let me add that in regard to the values you should add the offset of 0.045 to the seeing value as because I later found out ¿? how to add the offset to the Arduino sketch.

Interesting is that after many hours of measuring the sky the values start to diminish to unreasonable values and only umpluggin the sensor cable or restarting the Arduino brings it back to normality ¿ have you experienced that too ?

Tomorrow another session.

[PDB]

Hi Rainer,

seems I missed a few additions to this post. (Did not get any e-mails to warn me)
Never really thought about the DC offset, but what I noticed is that my seeing was much more optimistic with higher values. Maybe need to take my multimeter again and do some measurements.

I guess it all depends of focal length and resolution per pixel. Am I correct in assuming that the less resolution ( more arcseconds per pixel) requires a better seeing the high resolution (less arcseconds per pixel) or is it the way around ?

Well to my mind the limiting factor is your scope's maximum resolutiion when you use a camera that is not undersampled. In that case it will be the resolution of the camera which will be the limiting factor. Eg for my 80mm and ASI-120 @ f/24 I set the trigger usually around 1.2'' (scope = 1.5 theoretically)

I then use the SSM to trigger the start of a recording when seeind drops below that seeing level (hoping I will have some seconds of good seeing).

Regards,

Paul

[rsfoto]

Hi Paul,

Maybe need to take my multimeter again and do some measurements.

Measure from ground to pin 3 and 5 which are the ones which get the 2.5 Volt from the voltage divider with the 2x 10K resistors abd rest that value from 2.5 and you get the offset.

Have a Happy New Year 2018 ( while writing this still 15 hours to go )

Saludos

[rsfoto]

Hi,

Sitting in the observatory and making some tests I decided to connect an additional power supply to the Arduino and now the voltage at the 10K/10K divider is 2.488 Volt and so the offset is only 0.012 for the program.

Looks like I will have a small hole in the cloud cover :-) Let us see ...