I Calculating STEVE's Height from Two Photos 370km Apart

[astroscout]

A friend of mine was able to photograph STEVE and later found out that another photographer also captured the same event. One captured it from the south and the other from the north. He has asked me if using the the information from both locations, can the height of STEVE be calculated? The two photographers were about 370 km apart. Here is a drawing he sent me via Facebook.

 

[DaveC426913]

Link busted.
You can't link directly to Facebook.

Download the image to your drive, (right-click: 'open image in new tab', go to tab, right click: 'save image as...')
then upload it here as a file.Yes. You could calculate its height if you can get an accurate idea of the angle above the horizon from both pictures. That'll be easier said than done.

The next question is: will you get a more accurate altitude than that understood to be STEVE's normal.

According to Wiki, that's about 280mi.

 

[astroscout]

I tried but all I get with the image button is to paste a link. I see no option for selecting a file from my PC. Am I missing something?

 

[DaveC426913]

I tried but all I get with the image button is to paste a link. I see no option for selecting a file from my PC. Am I missing something?

Not on the toolbar. Bottom of message window: [UPLOAD], next to [POST REPLY].

 

[astroscout]

Got it . Thanx.

 

[DaveC426913]

Yes. As described. That's how you'd calculate it.

Those "known angles" oughtta be tricky tho.

(I thought you were going to upload the actual pics... )

 

[astroscout]

I just contacted my friend and he will send them and I will post them here. The other photographer has not responded to his message yet so it could be a while Here is a link to his youtube video of STEVE.

 

[berkeman]

What's a STEVE?

I just contacted my friend

Oh, your buddy. Got it.

(It's a good idea to define your acronyms, unless everbody in the target forum should know what it means.)

 

[astroscout]

berkeman...STEVE is a purplish colored skyglow event that is seen usually while auroras are present but they are unrelated. There is still a lot of research to be done though.

 

[berkeman]

berkeman...STEVE is a purplish colored skyglow event that is seen usually while auroras are present but they are unrelated. There is still a lot of research to be done though.

Interesting. What does the acronym STEVE stand for?

 

[astroscout]

STEVE = Strong Thermal Emission Velocity Enhancement

 

[DaveC426913]

There's something even berkeman doesn't know?
:cries with relief:

(intended to evoke a berkemanian smirk)

 

[astroscout]

Here is a screen capture of STEVE taken from the video at youtube.I enhanced it a bit to show the purplish color. This was taken by Paul Smith in Grassland, Alberta in Canada. He will use Stellarium to figure out the angle from his location.

 

[davenn]

Here is a screen capture of STEVE taken from the video at youtube.I enhanced it a bit to show the purplish color. This was taken by Paul Smith in Grassland, Alberta in Canada. He will use Stellarium to figure out the angle from his location.

ummm... that's the picket fence style aurora
STEVE is usually a single band, like a streamer across the sky

https://en.wikipedia.org/wiki/Steve_(atmospheric_phenomenon)

 

[astroscout]

I could be wrong about what I enhanced as being STEVE. I'll check with the photographer and will get back to you guys on this.

 

[astroscout]

I just checked with the photographer and the purple colored picket fence is indeed STEVE. I guess from some locations it will be seen as a single band and in others as an arc. I'm no expert so I will have to accept any other suggestions as to whether this is a STEVE event or not. I am going by the purple color and maybe the photographer is also.

 

[astroscout]

Here is another picture of the event from the same photographer. He says that the photos seen on the web are when STEVE is beneath. The one he captured was way north of STEVE. He also stated that his coordinates were 54.937806 -112.510886 and the other photographers was approx 49.709387 -112.866389.

 

[astroscout]

I just sent the photographer a link to this thread and I have advised him to sign up as a member of this forum and to answer any other questions you might have.

 

[davenn]

I just checked with the photographer and the purple colored picket fence is indeed STEVE. I guess from some locations it will be seen as a single band and in others as an arc. I'm no expert so I will have to accept any other suggestions as to whether this is a STEVE event or not. I am going by the purple color and maybe the photographer is also.

I have been observing aurora for 50 years ... I would be really surprised if it is a STEVE ... I have seen and photo'ed a number
of them over the years back in New Zealand, long before digital cams

Here's a scanned 1980's photo of mine from Dunedin, New Zealand
this arc went almost from horizon to horizon right overhead

Up to a few years ago, we all ( worldwide) were calling these things proton arcs ... It's only a couple of years ago that
the name change to STEVE was made when the truer nature of the arcs were better understood

I am 99.99% certain that SETVE's do not produce green picket fence type of displays ... that is just one form of normal aurora
And you need to be aware that purple in an aurora is very common

another couple from my NZ collection

Dave

 

[Paul m Smith]

Hello all. I am the original photographer of the Steve event and have lots of experience photographing aurora. I'm part of an online community called Alberta aurora chasers. The admin of this group is Chris Ratzlaff , he originally named the airglow band Steve and is very active in the citizen science community.This is indeed a Steve event that was observed for almost one hour by multiple people early morning April 10th 2018 over Alberta Canada. Sar arcs are a separate phenomena altogether. Steve events ( the purple/white ribbon) can sometimes be accompanied by the green picket fence lines which may originate from the same process as typical aurora vs Steve which is thought to be ionic drift. If there are any further questions about steve or this capture I would be more than happy to help any way I can. I thought it would be ground breaking and really interesting if the height / thickness of the band, and the size of the pickets could be determined from observations from multiple viewpoints. Thanks for any help

 

[Paul m Smith]

I should add . The green picket fence features are magnetically aligned substructures, thought to be produced by particle precipitation ( like typical aurora) . But they are exclusively observed accompanying Steve events

 

[davenn]

But they are exclusively observed accompanying Steve events

That I have to very strongly disagree with !

They are seen very regularly as part of typical auroral displays when there is absolutely no sign of a STEVE event

 

[Paul m Smith]

I'm sorry, but I am very well versed in aurora and vertical picket fence aurora is ONLY captured with STEVE events. There is literally no documented evidence of the contrary whereas there are hundreds of captures of picket fence aurora with STEVE. I have come here for help with a question and not to get uneducated responses. Please , I only ask for help with the question, I am not here to argue against invalid responses

 

[Paul m Smith]

I am working with another photographer to get an image with GPS coordinates and timestamp. I will be able to post a diagram to better illustrate the question. As a side note , these images and the video I captured have been requested and commented on by Elizabeth MacDonald who is a program scientist specializing in aurora and STEVE at NASA Goddard. It is a STEVE, without a doubt and indeed picket fence aurora ONLY occur during STEVE events. I have photographed aurora over hundreds of evenings and the picket fence is only there when STEVE is

 

[Drakkith]

It is a STEVE, without a doubt and indeed picket fence aurora ONLY occur during STEVE events. I have photographed aurora over hundreds of evenings and the picket fence is only there when STEVE is

Are these STEVEs always easily visible alongside the picket fence, or is there sometimes a reason the STEVE isn't visible? I only ask because I found several photos on google images that appear to show a picket fence aurora but no STEVE. Here's an example:

Perhaps the STEVE is the glow to the upper right of the aurora?

 

[davenn]

I'm sorry, but I am very well versed in aurora

likewise ... since 1960 and you ??

I have seen dozens of aurora with picket fence displays and many photos from other people with no STEVE present

 

[Paul m Smith]

Are these STEVEs always easily visible alongside the picket fence, or is there sometimes a reason the STEVE isn't visible? I only ask because I found several photos on google images that appear to show a picket fence aurora but no STEVE. Here's an example:

View attachment 236055

Perhaps the STEVE is the glow to the upper right of the aurora?

Thank you for proving my point. STEVE is right there in that picture above the pickets

 

[Paul m Smith]

likewise ... since 1960 and you ??

I have seen dozens of aurora with picket fence displays and many photos from other people with no STEVE present

You are not looking hard enough. STEVE will always be there , whether faint or out of frame

 

[Paul m Smith]

likewise ... since 1960 and you ??

I have seen dozens of aurora with picket fence displays and many photos from other people with no STEVE present

I just told you the facts coming from the mouth of NASA scientists and you a disagreeing? Please only comment if you are contributing to the question. I will respectfully ignore all other posts otherwise. I strongly urge you to research before you comment, the information is out there if you wish to be educated

 

[Drakkith]

I just told you the facts coming from the mouth of NASA scientists and you a disagreeing? Please only comment if you are contributing to the question. I will respectfully ignore all other posts otherwise.

Don't take offense from Davenn. We have no way of immediately knowing whether your claim is true, and personal experience is hard to trump without access to a reliable and verifiable source of information on the topic.

 

[Paul m Smith]

Don't take offense from Davenn. We have no way of immediately knowing whether your claim is true, and personal experience is hard to trump without access to a reliable and verifiable source of information on the topic.

Thanks, I understand. But there is a lot of reliable and verifiable information out there. Most of my learning is from the experts like Eric Donavan and Elizabeth MacDonald (both with NASA) with whom I interact via the Alberta Aurora Chaser facebook group. I cannot link information directly from there. I don't take offense to Davenn 's comments , but it is frustrating to face resistance from people who don't care to research.. I will get to the point and post the diagram when I can. My question will be more apparent then.

 

[Drakkith]

Thanks, I understand. But there is a lot of reliable and verifiable information out there.

Such information is much more difficult to find than you would imagine. Especially for many PF users who don't consider anything short of a textbook or a peer-reviewed paper reliable. A quick browse of the first fifty or so google and arxiv hits turned up nothing for me regarding whether or not STEVE always accompanies a picket fence aurora or not. So what information there may be out there isn't particularly easy to find. One thing I noticed is that this appears to have been seriously investigated only recently (around March of this year), which means that there is unlikely to be very much reliable information at all.

If you want to change peoples' minds, I suggest finding and providing links to reliable sources instead of telling people to "do some research".

 

[Paul m Smith]

https://www.facebook.com/PhenomenalSTEVE/
All information can be found here. Links to papers are within threads. Yes, it is a relatively new topic of research...

 

[astroscout]

Please guys...Lets focus on what is needed to calculate the height of the purple arc. If he were to get the angle using stellarium, can we calculate the height or do we need the info from the second photographer?

 

[Tom.G]

Gonna need that second observation... and hopefully a third one to get at least a vague idea of the error band.

 

[astroscout]

Thanx Tom. Good to know. We'll see what we can do.

 

[DaveC426913]

My concern is how you will be able to determine the angle above the horizon. You won't be able to calculate altitude without that.

I suspect that you'll need
1] a shot with the horizon (or other object with known angle) in the pic with the phenomenon
2] EXIF data from your camera that will include such things as focal length setting for the shot

Although, I suppose you could always reference any visible star formations in the shot. Coupled with time and date, that would do the trick. Yeah.

 

[astroscout]

I was able to use starry night software and astrometry.net to find the star formations and the altitude of Beta Sextantis using the timestamp and location of Paul Smith at the time of the photo.
Timestamp = April 10, 2018 at 1am
Altitude of Beta Sextantis = 22 deg
Location of the camera = Latitude = 54.937806 N Longitude = -112.510886 W

 

[DaveC426913]

I was able to use starry night software and astrometry.net to find the star formations and the altitude of Beta Sextantis using the timestamp and location of Paul Smith at the time of the photo.
Timestamp = April 10, 2018 at 1am
Altitude of Beta Sextantis = 22 deg
Location of the camera = Latitude = 54.937806 N Longitude = -112.510886 W

OK, can you do the same with the other one?

 

[astroscout]

Paul has not been able to contact the other photographer yet. Hopefully he will. If he can't, can the info I found be enough to get an approximation?

 

[DaveC426913]

Paul has not been able to contact the other photographer yet. Hopefully he will. If he can't, can the info I found be enough to get an approximation?

No.

I mean, no better than simply checking the general understanding of STEVE altitude. If you want to add to the body of knowledge, you'll need that other photo.

You know, that photographer is surely not the only one who took pics of that particular event. Looking around the webernets, you could probably gather quite a few photos and correlate them all.

Wait. You mean you found another photo in addition to the photographer's? Then yes. If you can find the location and date/time of the other photo.

 

[astroscout]

We will continue to try to contact the other photographer and get the info needed. Thanks Dave.

 

[stefan r]

Please guys...Lets focus on what is needed to calculate the height of the purple arc. If he were to get the angle using stellarium, can we calculate the height or do we need the info from the second photographer?

Do we know the STEVE (or the aurora) is radiating the same in all directions. Rainbows make a counter example. Someone else sees violet in the section where you see red. The red photons you see are coming from water droplets over a deep range. Two photos of a rainbow would not accurately tell you where a squall line was located.

 

[Tom.G]

Here is a rather detailed semi-technical article on STEVE published in SCIENCE magazine.

http://advances.sciencemag.org/content/4/3/eaaq0030.full

Cheers,
Tom

 

[TEFLing]

Plasmasphere cools and contracts on Earth's night side, leading to radially inward current flows, if I understand correctly

https://wiki.oulu.fi/download/attachments/5243547/plasmasphere.gif

https://wiki.oulu.fi/display/SpaceWiki/Plasmasphere

Out beyond the Plasmasphere, where the plasma is tenuous and relatively warm, whistler-mode waves create primarily rising chirps, like a flock of noisy birds. This type of wave is called chorus and is created when electrons are pushed towards the night side of Earth... When these low energy electrons hit the plasma, they interact with particles in the plasma, imparting their energy and creating a unique rising tone.https://3c1703fe8d.site.internapcdn.net/newman/gfx/news/hires/2017/1-nasalistensi.jpg

https://phys.org/news/2017-07-nasa-electrons.html

 

[TEFLing]

"The ring current (e.g., Frank, 1967) consists of geomagnetically trapped 10 - 200 keV ions (mainly H+, He+, and O+) and electrons that drift azimuthally around the Earth at radial distances of about 2-7 Re (Earth radii), overlapping the radiation belt region. The drift is a combined curvature and gradient drift which is eastward for electrons and westward for ions, i.e., the direction of the current is westward ."

https://wiki.oulu.fi/display/SpaceWiki/Ring+current

 

[astroscout]

Here is the photo taken by the other photographer, Savoie. Looks like he didn't get the top of the arc like Paul did so I guess we are out of Luck in trying to figure out the height of it. Any Suggestions?

 

[DaveC426913]

Here is the photo taken by the other photographer, Savoie. Looks like he didn't get the top of the arc like Paul did so I guess we are out of Luck in trying to figure out the height of it. Any Suggestions?

If it were possible to identify common elements of each, you should be OK.

But - it's also possible that STEVE's change fast enough that, even if they were taken less than a minute apart, they would have no common elements.

Unfortunately, the implication that is that the boundary of the phenomenon - including its maximum height - is ever-changing.

And that means any attempt to triangulate its height would be little better than a vague estimation.

 

[astroscout]

Thanx Dave. The only common elements is the picket fence that comes and goes in their videos. I'll see if I can find anything in STEVE.

 

[DaveC426913]

Here is the photo taken by the other photographer, Savoie. Looks like he didn't get the top of the arc like Paul did so I guess we are out of Luck in trying to figure out the height of it. Any Suggestions?

Were you able to get any time/location alt/azimuth and direction info on this one?