Author Topic: Chad pictures  (Read 43980 times)

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Offline 10538

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Re: Chad pictures
« Reply #45 on: June 10, 2008, 04:12:06 pm »
Is there EXIF data for Chad's photos? I'm curious about the time of day and the effect that sun angle is playing on the shadow cast on the tree.

No exif for those.  They are scans.  Going by the shadows and using the Navy sun angle chart, I would guess it would be about 3:00 pm.

Offline tomi

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Re: Chad pictures
« Reply #46 on: June 10, 2008, 05:33:25 pm »
Send me exactly what you want to ask him in a PM and I will copy it and send it to him.  In other words, you specify the questions and I will send them on.

Offline Kaelos

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Re: Chad pictures
« Reply #47 on: June 10, 2008, 06:24:06 pm »
Thanks for your work, a very important question...

Please, is it possible to give on a Google sight:

the exact orientation of chad's drone as seen on pictures (tail/ring) ?

A correlation with meridian, fault etc. could be done!


Same question for Raj and Ty of course...

Thanks

Offline spf33

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Re: Chad pictures
« Reply #48 on: June 11, 2008, 03:25:52 pm »
In other words, you specify the questions and I will send them on.

will do.  after lengthy phone conversation with the usgs, it was determined
that my questions needed to be fielded to someone with the appropriate knowledge, this person is supposed to return my call sometime thurs or after.  so let me have that conversation and digest it before i can think what to relay to the surveyor.

very cool conversation about the limits of DEM files, stuff i couldn't actually find online, how tree canopys affect data - especially evergreens, about resolutions, and about a new type of data they are incorporating into the ned on the national map seamless server - lidar which if i can figure out a way to get into max should give over twice the resolution being at 3m.



Offline 10538

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Re: Chad pictures
« Reply #49 on: June 24, 2008, 07:00:53 pm »
Can somebody tell how far the drone is from the camera?



Thanks


Offline nekitamo

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Re: Chad pictures
« Reply #50 on: June 26, 2008, 07:35:33 am »
Here's my estimate based on image FoV angle comparison and previously calculated size of the drone:



I assumed some vegetation growth, as you can see through slightly transparent Chad's image, and also included control distance to elevenaugust for comparison.

Btw, those 15m laser measurements in your image seem to indicate that distance measurements were taken from the spot slightly more to the left from the above background image? Judging by the apparent size of those trees/bushes, the one on the left is obviously far more distant than the other.

Offline 10538

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Re: Chad pictures
« Reply #51 on: June 26, 2008, 04:54:32 pm »
Thanks, Nekitamo.

I'm trying to ascertain the feasibility of the shadow on the bush being cast by the drone.



What do you think?




majicbar

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Re: Chad pictures
« Reply #52 on: June 26, 2008, 05:34:45 pm »
I'm pretty sure that the drone arm that is causing the shadow is the next one back, if the indicated arm were the one causing the shadow, then the crown antenna would also be casting a shadow on the tree, where the arm back would allow the crown antenna shadow and other shadows from the drone to fall in front of the tree. It might be a good execrcise to establish the time at which the photograph would have been taken to establish the sun azimuth angle to confirm the arm causing the shadow and to reconfirm the drone size.

Another question that comes to mind is the depth of field that is exhibited in this drone photograph, while it does not appear to exceed reasonable values, does the drone show sufficent depth of field given its range in the photograph and the scale of the scene?

Offline 10538

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Re: Chad pictures
« Reply #53 on: June 26, 2008, 06:32:57 pm »
I'm pretty sure that the drone arm that is causing the shadow is the next one back, if the indicated arm were the one causing the shadow, then the crown antenna would also be casting a shadow on the tree, where the arm back would allow the crown antenna shadow and other shadows from the drone to fall in front of the tree.
Yes, I'm open to that possibility.  My concern is that the angle of the shadow is not consistent with the other arm.  The shadow would be pointing more away from the camera it would seem.  I also considered the crown.  It could be that only the tip or outer half of the arm is casting a shadow that we can see in the photo.  Because the bush has a more vertical side, the shadow is elongated.

Quote
It might be a good exercise to establish the time at which the photograph would have been taken to establish the sun azimuth angle to confirm the arm causing the shadow and to reconfirm the drone size.

Another question that comes to mind is the depth of field that is exhibited in this drone photograph, while it does not appear to exceed reasonable values, does the drone show sufficient depth of field given its range in the photograph and the scale of the scene?

Agreed.  I think the exif from our photos would help in determining angle and azimuth.


Offline BigFnTuna

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Re: Chad pictures
« Reply #54 on: June 26, 2008, 07:05:14 pm »
Another question that comes to mind is the depth of field that is exhibited in this drone photograph, while it does not appear to exceed reasonable values, does the drone show sufficent depth of field given its range in the photograph and the scale of the scene?

Just a quick note, using Pythagorean, the drone looks to be 27-30 meters away and a similar height off that line of sight, IMO...

Tuna

Offline nekitamo

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Re: Chad pictures
« Reply #55 on: June 29, 2008, 11:19:47 am »
I'm trying to ascertain the feasibility of the shadow on the bush being cast by the drone.
What do you think?

I didn't consider this likely, but after some crude analysis it seems you could be right:
 


But here's something that we should double check before attempting serious 3D analysis: if I've correctly identified the tree marked with 85m in this mapquest aerial image, note that it is much closer to Chad's position than indicated - so perhaps the detectives used some other spot for their measurements (somewhere on the edge of drawn red circle)?

Offline onthefence

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Re: Chad pictures
« Reply #56 on: June 29, 2008, 11:44:16 am »
I didn't consider this likely, but after some crude analysis it seems you could be right:

One fin position should be moved.


Offline nekitamo

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Re: Chad pictures
« Reply #57 on: June 29, 2008, 11:55:41 am »
You're right, I didn't notice this - a flaw of the 3D model used (by goobermaster@OMF).


Offline Kaelos

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Re: Chad pictures
« Reply #58 on: June 29, 2008, 06:13:42 pm »
Thanks Nekitamo and OTF!

Could you give the exact orientation of the drone...on this picture and also on the others?

May be we could do a correlation with ground particularities like: meridian, fault, water, trees, roads, hightways... and what we could imagine!

Great thanks for your work!

Offline leviathan

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Re: Chad pictures
« Reply #59 on: June 29, 2008, 06:20:59 pm »
Wonderful work from people who know what they are doing.
IC
We at L E V I A T H A N were banned from the UFO Casebook Forum and it is so sad.
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