Size, position and orientation of the captured U.S. stealth drone in Iran: an architect's analysis

Dec 23 2011 - 10 Comments

Many speculations and very few known facts surround the mysterious capture of the U.S. stealthy RQ-170 Sentinel drone in Iran. While the U.S. claim that the robot was lost as a consequence of a technical failure occurred during a spy mission from Afghanistan (the version that, backed by some local accounts, I consider now the most likely), Iran has always affirmed that the once secret UAS (Unmmanned Aerial System) was ambushed using a GPS-spoofing attack along with a complex cyber warfare operation that enabled its military to take over remote control of the Lockheed Martin robot.

Official statements aside, the only things we can be sure of are the images of the drone showcased in what looks like a gymnasium of a school, made available by Iran’s Revolutionary Guard website.

Whether you belong to the “party” of those who believe the drone is real or you think it is a fake, those pictures ,alongside the footage released by the State TV, are the only proof that the one in Iran is indeed the elusive ‘bot dubbed the “Beast of Kandahar”.

Many details can be discovered by analyzing the few available images that, at the same time, raise many more questions.

Bjørn Holst Jespersen is a Danish architect who has been following the developments of the saga of the Beast of Kandahar on this blog since the beginning. I’ve asked him to check if the gymnasium where the drone was showcased is compatible with the one pointed out a few days ago by a source as the location where the Sentinel was hidden.

Using perspective drawing techniques, by extending lines and establishing vanishing points to subdivide areas using diagonals, he has studied the photographs of the captured RQ-170 to determine both the building and drone size as well as the orientation of the gym.

Here is what he was able to ascertain from the images.

Size

It seems the gym-space is 36-meter long (6×6 meter sections) and about 20-meter wide. The building/drone size is calculated on the basis of markings on the floor. “The assumptions that I have based the reconstruction on are that the circle in the middle is a standard centre circle for basketball, and that there are markings (white lines) for volleyball”  Bjørn says.

“Markings correspond and point to a constructive section being 600 cm centre to centre (this is established by extending the lines until they hit the wall) corresponding with standard size Iranian brick that I googled. This together makes a strong case for the length of the building: the bricks can be larger than standard, but that would make the 300 cm markings for volleyball too wide and also make the 360 cm diameter basketball centre circle too large” the Danish architect explains.

“The width of the building was harder to get a handle on but based on the same assumptions I don’t see the gym-space being more than 20-meter wide. With walls and overhang this would be about 22 meters…unless the court is placed asymmetrically(!).

Orientation

By establishing the vertical sun-angle the solar-time (using this calculator) can be determined. This gives the compass-direction to the sun. By establishing the horizontal angle of the entering sun, the orientation of the building can be ascertained, giving an AM and a PM value.

“The drawing explains “which ray” I calculate. Since the lengths of the sides of the horizontal triangle is calculated from counting bricks, the brick size becomes irrelevant, but the counting could be wrong as could the estimated “entrance point” of the ray. Furthermore, the calculation is based on the end-wall leaving no gap behind the last steel frame. The further back the wall is, the more the horizontal angle will fit the building pointed out by the source.”

“The vertical solar angle is possibly lower than I have assumed due to 3 layer of bricks being 18 cm instead of 20 as I have used (have done some more googling since). This will set the time of day to 09.33 AM or 02.27 PM. If this is the case (and the horizontal angle is correct) the building pointed out by the source will be only 5 degrees off” Bjørn says.

Conclusion

According to Google Maps/Google Earth the size of the building identified by the source as the one where the drone is/was hidden is significantly bigger than that the architect has found (about 5 meters longer and some meters wider too).

However, as Bjørn says:  ”I cannot entirely exclude that I have made some error or – less likely – that the building is larger than the gym-space. I cannot even say how precise the measuring on Google Maps is. But if the building only has the gym-space, and the measuring on Google Maps is precise I’m close to excluding it as the right location. The ratio of length vs width looks about right.

Dealing with the orientation of the tiped off building: “compared to my the sun-angle study it seems to be about 5 degrees off at AM. This is more than I would like to accept as a margin, but realistically, it is still quite possible. (PM is impossible unless photos are mirrored).”

The two reference figures inserted in the satellite images at the bottom are not exact in size, only in orientation. The tiped off location is still within the margin of error – even though close to falling outside. Both because of the orientation, but mainly because of the size which seem too big.

So, if the U.S. were studying a raid on this gymnasium near Kashmar to free their drone, maybe it’s better they reconsider it…. :-)

Stay tuned.

This, along with all the previous articles on the Sentinel drone in Iran, can be found at the following link (click and scroll down): http://theaviationist.com/category/captured-stealth-drone/

  • iskandar

    Dear Bjorn,

    I think you did an excellent job. With less sophostication, I have looked at the images and I came up with an estimate of 5.3 meters between the steel profiles (counting bricks). AS is apparent from your graphs and my personal estimate, this would result in a wingspan of the “thing” between 15 and 18 m. As far as I have been able to find, the RQ170 should have a wing span of 28m. This far beyound the measuring error you or I have made.

    Conclusion?
    Either the specs I found for the RQ170 are completely wrong, or this is a hoax.

    • bjoern holst jespersen

      The specs of the RQ-170 are guess work. And – as far as I have read – with no other basis than previous drones and the Kandahar photos.
      The wingspan I get is as low as between 13 and 14 meters which is much lower than the 18 to 26 meter I have read. However this doesn’t change my mind about the “thing” in the pictures being real. Actually, I don’t see the Iranian army making a fake and then not making it fit the general trend in estimated specs.

      Btw. what size do you use as brick-size? I found two: 21×9.5×5.5 cm and 22x10x5 cm, and I’m leaning towards the second.

      • iskandar

        Dear Bjoern,

        I used the 22 size, just based on my experience as a hobby mason and added 1 cm for the mortar.

        When the width of the steel profiles (22 to 30 cm was my guess for a single profile) is taken into account, we come up quite close to the same value.

        • bjoern holst jespersen

          Yes we do. And thanks for your positive comment.

          My estimate is about 30 cm for the steel frame.

  • iskandar

    Dear Bjoern,

    That is exactly what I thought about the steel frame. In my opinion, a standard I22 profile would be too weak to support a roof as high as depicted so I went for a I30 profile.

    On another topic, would it be possible to correlate the date,time stamp of the images to your solar calculations? That would enable the calculation of an almost exact position of the GYm. might be revealing!

  • iskandar

    Dear Bjoern,

    Are you related to the famous composer Gustav Holst?

    • bjoern holst jespersen

      no known direct relation.

  • iskandar

    Dear Bjoern,

    If you are correct on the size of the “beast of Kandahar” (which I assume to be true) then this depicted “drone” can not fly.. The wing profile is completely wrong, not according to what I know. I have asked Professor Claes Johnson to join in this discussion.

    • bjoern holst jespersen

      Hi Iskander.

      Thanks for the info on standard steel frames. It further confirms that our calculated sizes aren’t that fare off.

      About the date: I have set the date of the pictures to dec 7. but possibly it should have been the 8th(?). Please elaborate on the time-stamp. And I agree a possible cross reference with the clock-time could be useful.
      It would also be interesting to have the professor elaborate on his opinion.

      • iskandar

        Dear Bjoern,

        With the time stamp I meant the EXIF info that might be present with some of the images. It may even hold the GPS coordinates if the camera was able to record them! (although that would be sign of a blundering which would be unimaginable) I have not looked for them yet, been busy with other things laterly.