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

[astroscout]

@Siv Heang Tav I am now a member of the AAC so send it to me via personal message.

 

[Tom.G]

The link to 'rextester' resolves to 'no name found', the URL resolves to 5.35.224.2 which is an un-assigned address at the ISP 'hosteurope.de' in Germany.

 

[Siv Heang Tav]

@Siv Heang Tav I am now a member of the AAC so send it to me via personal message.

Cool, PM me on my Facebook Siv Heang Tav

 

[Bill Archer]

@Bill Archer @DaveC426913 I have a friend from Hungary named Jozsef Bor (http://www.ggki.hu/en/staff/researchers/bor-jozsef-mta-ggki/) that is in the process of trying to find a code that will take into account both photographers location and the curvature of the Earth and he will try to help us find a way to figure this out.

In the mean time, I used his code and assumed that STEVE was in between both photographers, in Latitude only, and got 157.363952 Km. This is a very big assumption so the results are not valid at all. I guess it is just a coincidence, but strange, that it is very near what Dave had calculated.

You can see the code and the Octave at this website:
https://rextester.com/YAXQ35757
https://rextester.com/l/octave_onli...eBfHoGePd5szW4Y5QFHHfQcmW7kiR2g6c4cPFjBaT4Pa4

Let me know if the links work.

I expect your answer of ~160 km is about right. From what I have seen so far anything between 130 and 230 km seems reasonable. Some of the differences in answers that people are getting probably from the different techniques used, but it is just as likely from genuine geophysical differences between events. It might be fun for multiple techniques to be used on a single event to see just how much it affects the altitude you get. I would not be surprised if the straightforward approach that does not account for the curvature of the Earth gets you 90% of the way there.

I also wanted to note that the "170 km" altitude stated earlier in the thread from my colleague Dr. Gallado-Lacourt is (I believe) based on red-line data. Although it is not apparent in the pictures Steve radiates in red wavelengths as well, very likely at different altitudes than at other frequencies.

-Bill

 

[astroscout]

It might be fun for multiple techniques to be used on a single event to see just how much it affects the altitude you get. I would not be surprised if the straightforward approach that does not account for the curvature of the Earth gets you 90% of the way there.

@Bill Archer Sounds interesting. My other approach to this is to find a longitude and latitude where steve can be seen looking straight up at about 90 deg and then use that location as a reference or a constant in the code. I will still need the location of other photographers, with the same timestamp, and who are located at a higher or lower latitude, but preferably not too far off in longitude. I could then use the same code that I used to calculate the height of my Gigantic Jet.

 

[TEFLing]

If we have any home radio astronomers, from what I've learned online, SAID / STEVE is associated with EMIC waves in the ELF / ULF spectrum, both deriving ultimately from the same population of westward drifting Ring Current cations (STEVE at high latitudes near the earth, EMIC at low latitudes far from the earth, but same ions on the same field lines)

 

[astroscout]

@Bill Archer I just got a facebook message from Andy Witteman of the AAC and here is the quote:

"In Fairbanks, we're a bit too far north to see him out (we've had 2 this year) but back in BC last year it was like a once a week thing. you would almost be best off setting up 3 or 4 webcams in ideal locations (BC, AB, YT, and NWT) and catching it that way. Its line of visibility is huge and that might give you a fighting chance at matching features within it!"

The part I like about this is that instead of using webcams we can use Watec cameras in different locations, where STEVE is most likely to be seen most often. Now, we would need the funding for something like this but it might pay off in the data we can get. If you set them up properly, you will be able to determine its height at every event and maybe figure out why it's height changes.

The last two of my captures below are soon to be published in scientific papers by the Florida Institute of Technology. One will be by Steven Lazarus and the other by Levi Boggs. All three were taken with a Watec 902H2 Ultimate camera mounted in a Watec APAQ2000 SERIES housing.

This camera was originally installed at the Arecibo Observatory but was relocated to my house in Cabo Rojo, Puerto Rico because of possible interference at the Observatory. I was asked to participate in a meteor campaign that was run by John Mathews of Penn State University. My job was to capture a visual of a fragmenting meteor over the Observatory while the Lidar at the Observatory captures the data within it. Hurricane Maria put a halt to this campaign but we will resume the campaign soon.

 

[astroscout]

@DaveC426913 @Bill Archer I just got some feedback from Jozsef Bor and he examined the photos we were using for the calculations and indicated, like what @DaveC426913 indicated also, that there are no common elements. I guess we will just have to wait for the next STEVE event and hope that we get the timestamps and locations of the photos that have common elements in them.

He did give me this link to some formulas that might help us later on.
https://www.movable-type.co.uk/scri...n8Azn0lF7k6L2e85A0FhWSaqiuXmVWprridXFkSc9Qhj8

 

[astroscout]

@Bill Archer @DaveC426913 I recently found a pair of images that could have been taken just seconds apart. I decided to find the highest altitude star, within the ribbon of Steve, for each photo and use that in the formula that @DaveC426913 used in his calculation.

I first found the highest altitude star in Alan's photo and then Jun's photo by using Starry Night Pro ver 6.
Chi Ursae Majoris (Alan) = 69 Deg
HIP67250 (Jun) = 73 Deg

I then calculated the distance between them using a link that Jozsef Bor sent me that factors in the curvature of the earth:
https://www.movable-type.co.uk/scri...ddfwETl9mb_a_NIw0pOgC6XP1A0CBS2zZFhqKZNun1iwI
and got 120 Km

Then I used @DaveC426913 link to calculate the height:
https://keisan.casio.com/exec/system/1272724233
and I got 173.01 Km as the possible height of Steve.

Jozsef Bor tried to do the calculation using a formula that factors in the azimuth and the elevation of each observer but came up with 347 Km as the possible height of Steve. That result is interesting because if you divide 347 Km by 2 you will get 173.5 Km.

The final result I got of 173.01 Km could be a fluke so we will have to attempt this same method again with the next Steve event to see if we get similar results.

 

[DaveC426913]

I recently found a pair of images that could have been taken just seconds apart.

Cool. Do you know the lat/long of the two locations?

 

[astroscout]

Yes... @DaveC426913 but I was asked not to post it because They were taken near their homes. I decided to just post the distance between them which was 120 Km.

Jozsef and I decided that the best way to approach this is to find an image that is directly below Steve and that one of the stars within the steve ribbon is very close to the 90 deg altitude. We will then use that location as our reference location for the other photos of Steve. We still need for the timestamps to be the same as the one at the reference location.

@Bill Archer I believe that you guys at the University of Calgary have an all sky cam. If the stars can be clearly defined, then we can use your location as our reference if Steve appears directly overhead. Then we could check for the timestamps of the others to see which ones match up. I will then use the same code I used to calculate the height of my Gigantic Jet a few months ago.

I am still planning on using the method I used to get the 173.01 Km result in my previous post. If we can achieve being able to use both methods, then comparing both results should be very interesting.

 

[DaveC426913]

I recently found a pair of images that could have been taken just seconds apart. I decided to find the highest altitude star, within the ribbon of Steve, for each photo and use that in the formula that @DaveC426913 used in his calculation.

Hang on. Something's fishy.

Both pics are taken from the same side of the phenomenon. (They are both looking North.)

It's an obtuse triangle with one angle being greater than 90 degrees.

Unfortunately, that produces a height of 1,535km!

Here's a visual calculator.

 

[astroscout]

@DaveC426913 Could this be why Jozsef was getting erratic results when factoring in the azimuth and elevation?

Is there another formula that we can use in this case?

Jun Wang was located directly north of Calgary and Alan was located southeast of calgary. They were about 120 Km apart.

 

[DaveC426913]

Is there another formula that we can use in this case?

The formula works fine. You just have to examine the geometry and recognize the correct larger angle is the complement (180-73=107)

 

[astroscout]

The formula works fine. You just have to take examine the geometry and recognize the correct larger angle is the complement (180-73=107)

So, is the result I got of 173.01 Km a reasonable calculation?

 

[DaveC426913]

So, is the result I got of 173.01 Km a reasonable calculation?

No.

The geometry you used assumes they were on opposite sides of the phenomenon. They are not;
- both pictures see the phenomenon toward the North of the image.
- both pictures are oriented the same way - if one were looking Southward at STEVE, the arc should be flipped (mirrored). Instead, it is merely rotated in the image itself. I corrected for the rotation of the image, but I wouldn't be able to correct for the flip without flipping the image. See top diagram, post 112, above.
So, both observations are - generally - parallel.

The formula takes the inside angles as input. The inside angle of an observer looking North will be the complementary angle - i.e. 180-73=107.

See diagram, post 112, above.

 

[astroscout]

Thanx @DaveC426913 When Jozsef came up with erratic results I kinda figured that my result of 173.01 Km was a fluke.

Hopefully, in the next Steve event we will get a location where Steve is directly overhead and then I will use the same code I used for my GJ event a few months ago.

There is still a chance that we might get photos from both sides of Steve in the next event, so fingers crossed.