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Poor man's LIDAR ?

  • 30-07-2012 4:46pm
    #1
    Registered Users Posts: 316 ✭✭


    I've been experimenting with using aerial photography (from camera laden RC-Plane) as an archaeological surveying tool to capture 3D surface topgraphy.. Photogrammetry is a relatively new computational technique that discerns the three dimensional character of a target from a series of photos taken from slightly differing (and overlapping) perspectives. The posted picture is of a model I've created using this technique of the earthwork remains of a 17th century star fort in Duagh, Waterford (Can make it out from this Bing Satelite Image: http://binged.it/M5wsYj). Any thoughts?

    7677708352_b3af2380a8_b.jpg


Comments

  • Moderators, Science, Health & Environment Moderators Posts: 5,218 Mod ✭✭✭✭slowburner


    Simon.d wrote: »
    I've been experimenting with using aerial photography (from camera laden RC-Plane) as an archaeological surveying tool to capture 3D surface topgraphy.. Photogrammetry is a relatively new computational technique that discerns the three dimensional character of a target from a series of photos taken from slightly differing (and overlapping) perspectives. The posted picture is of a model I've created using this technique of the earthwork remains of a 17th century star fort in Duagh, Waterford (Can make it out from this Bing Satelite Image: http://binged.it/M5wsYj). Any thoughts?
    Fascinating.
    Can an image be rotated in all directions?
    If so, I could see this as a powerful tool, and not just for archaeological applications.
    Landscape archaeology is nothing more than refinement of the capacity for discerning topographical patterns.
    Any method which aids this capacity has to be good for archaeology.
    Without doubt, such a technique could reveal previously unnoticed earthworks, especially when employed at a macro level.

    I can certainly think of quite a few places where I would dearly love to see your rc plane frightening the birds ;)
    If you're interested, drop me a pm to discuss.

    Is the aspect in your photogrammetric image (sp.?) the same as the Bing image, by the way?


  • Banned (with Prison Access) Posts: 1,934 ✭✭✭robp


    Simon.d wrote: »
    I've been experimenting with using aerial photography (from camera laden RC-Plane) as an archaeological surveying tool to capture 3D surface topgraphy.. Photogrammetry is a relatively new computational technique that discerns the three dimensional character of a target from a series of photos taken from slightly differing (and overlapping) perspectives. The posted picture is of a model I've created using this technique of the earthwork remains of a 17th century star fort in Duagh, Waterford (Can make it out from this Bing Satelite Image: http://binged.it/M5wsYj). Any thoughts?

    7677708352_b3af2380a8_b.jpg

    Very nice result. I surveyed that site for my undergraduate and wow it was a lot less visible using our basic surveying approach.


  • Registered Users Posts: 316 ✭✭Simon.d


    slowburner wrote: »
    Fascinating.
    Can an image be rotated in all directions?
    If so, I could see this as a powerful tool, and not just for archaeological applications.
    It's a 3d model, that can be spun round in all directions... Here's another output from it: EOPIF.gif
    slowburner wrote: »
    Is the aspect in your photogrammetric image (sp.?) the same as the Bing image, by the way?

    The aspect I posted of the model is from a North West point of view. You can see the depression of the stream (partially cut off) in the model going along the north & west edges of the site, which should help you line it up with the Bing satelite perspective....


  • Registered Users Posts: 1,676 ✭✭✭dr gonzo


    Very interesting and very well done! You might be interested to know that remote control planes and the like are actually being used in archaeology at present to a smallish degree. I believe ROV's are being used to great effect in the Vale of Pickering in Yorkshire at present, although I havent seen the results.

    That is not to take away from what youre carrying out yourself of course. Keep up the excellent work and throw stuff up here when you can, I'm sure I'm not alone is wanting to see more of what youre coming up with.


  • Registered Users Posts: 69 ✭✭Briskit


    Interesting work there Simon.d

    It's amazing what the individual can get around to doing in this day and age without needing €millions on equipment. I'm sure you've invested plenty in your RC plane and the technology you're using, but it is still very impressive to see you end result like that... especially how you can rotate it around and view if from all angles.

    The RC aspect also gives the individual that extra capactity to get to places where a hiker might not be able to go... Very good of you to have highlighted this method your using as its always nice to learn something new.


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  • Moderators, Science, Health & Environment Moderators Posts: 5,218 Mod ✭✭✭✭slowburner


    Incredible imagery.


  • Moderators, Science, Health & Environment Moderators Posts: 5,218 Mod ✭✭✭✭slowburner


    Bit of an aside, but I wonder what the ridges are in this area?


    216035.jpg




    Image above is from here in the original image

    216033.jpg


  • Registered Users Posts: 316 ✭✭Simon.d


    slowburner wrote: »
    Bit of an aside, but I wonder what the ridges are in this area?


    I think this is them: https://maps.google.ie/maps/myplaces?ll=53.719492,-6.481376&spn=0.015364,0.042272&ctz=-60&t=h&z=15 .. Mushroom Farm?


  • Moderators, Science, Health & Environment Moderators Posts: 5,218 Mod ✭✭✭✭slowburner


    I'd guess you're spot on there.

    It's interesting to note how the topographical feature eastward of the mushroom farm, is not visible in the Google image.

    216039.jpg216040.png


  • Registered Users Posts: 69 ✭✭Briskit


    Simon.d wrote: »

    Imagine if google maps had a LIDAR layer..



    ...A Really Nice preview of the future there... I hope... you did a very nice job of accurately overlaying the two shots...

    Is there anyway of creating an animated gif like the one you just did, but where the laser image would only be seen if you held the cursor over the image? so that you could interchange the picture at the rate you want it??

    Thanks for the cake by the way, it's always just a thing with me with always trying to eat some of it!!


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  • Registered Users Posts: 316 ✭✭Simon.d


    Briskit wrote: »
    Is there anyway of creating an animated gif like the one you just did, but where the laser image would only be seen if you held the cursor over the image? so that you could interchange the picture at the rate you want it??

    I don't think it can be done with a gif, but you can you can use arrow keys to alternate them here: http://imgur.com/a/cDl4j#1


  • Registered Users Posts: 69 ✭✭Briskit


    Simon.d wrote: »
    I don't think it can be done with a gif, but you can you can use arrow keys to alternate them here: http://imgur.com/a/cDl4j#1

    Super... absolutely spot on... just tried this here and its the bees knees... exactly what I wanted...

    Also, you're introducing me to a new 'photobucket' type site in imgur. Many Thanks. Love finding out new things and also good websites.

    Funny... you come to the Archaeological forum and you end up talking about the future & google earth etc., and getting more abreast of technological updates... Cool paradox


  • Moderators, Science, Health & Environment Moderators Posts: 5,218 Mod ✭✭✭✭slowburner


    Briskit wrote: »
    Super... absolutely spot on... just tried this here and its the bees knees... exactly what I wanted...

    Also, you're introducing me to a new 'photobucket' type site in imgur. Many Thanks. Love finding out new things and also good websites.

    Funny... you come to the Archaeological forum and you end up talking about the future & google earth etc., and getting more abreast of technological updates... Cool paradox
    Well if the technical wizardry here is anything to go by...who says archaeology is all dirt and sweat.

    Thinking even further into the future, I suspect a time will come when excavation will be looked back on with horror.
    Without doubt a technology will be developed which will give as much (if not more) information about a site, and without any form of destruction.
    I heard recently of a geo-physics technology which can detect the existence of buried human remains up to two hundred years old.
    It's something to do with the conductivity of the soil in the immediate area being altered by the decomposition of electrolytes in the corpse.

    I often wonder to what extent archaeology is the developer of such technologies, rather than the borrower.


  • Moderators, Science, Health & Environment Moderators Posts: 5,218 Mod ✭✭✭✭slowburner


    Simon.d wrote: »
    Here's an attempt to clarify what's what:


    There's a faint indication on the LIDAR of a large circular enclosure (about 100m in diameter) evident around this mound to the north of the soccer pitch https://maps.google.ie/maps/myplaces?ll=53.718822,-6.472235&spn=0.00096,0.002642&ctz=-60&t=h&z=19

    Imagine if google maps had a LIDAR layer..
    That's the one I was referring to above.

    Thanks for the gif but it should probably come with a health warning - you know, like when they warn about flash photography before a tv clip.:D

    Thank heavens Google doesn't have access to Lidar...yet, I'd never get away from the screen.


  • Registered Users Posts: 69 ✭✭Briskit


    slowburner wrote: »
    Well if the technical wizardry here is anything to go by...who says archaeology is all dirt and sweat.

    Thinking even further into the future, I suspect a time will come when excavation will be looked back on with horror.
    Without doubt a technology will be developed which will give as much (if not more) information about a site, and without any form of destruction.
    I heard recently of a geo-physics technology which can detect the existence of buried human remains up to two hundred years old.
    It's something to do with the conductivity of the soil in the immediate area being altered by the decomposition of electrolytes in the corpse.

    Yes indeed... have to agree with you on all points. I like this non-invasive archaeological style as well and often wonder if our predessors were not throwing away the most valuable aspects of digs with their more rugged approach...

    I like that idea of using electrolytes to measure for corpse location. There was something similar a few years back in Guatemala & Honduras, where a lot of Mayan architecture and structures remain buried in jungles. They found a way of measuring a difference in folliage from outer space via - well, it seems that the stones used to builid certain structures like Tikal/Copan/Palanque use limestone (I think), and that trees and shrubs growing on old sturctures absorb more lime, thus it has some affect on Chlorophyll, so that they could utilise NASA satelites to distinguish and area of the forrest with such an affect with infrared or UV imagery or the likes, and from there they could then send out a team to probe it, as appossed to just prodding around in the dark...

    I just finished a book this summer about a Henry Rawlinson deciphering Cuniform around the 1850's out in Persia and Mesopotamia... Very interesting, but when you read the descriptions of how they (his peers) dug into sites and then pryed out great sculptures with crobars to send home to museums in London & Paris... its kind of harsh to modern ears but I guess it was a different time then! .. and sometimes, they even had to cut large stone sculptures in two to make them more transportable and manageable!!!! Ouch.

    However, I do like how Dr O'Kelly left a certain percentage of Newgrange unexcavated so that it would be available for future scholars and better techniques... now there's a forward thinking individual who probably would have been a technological innovator had he not passed away so young.

    "I often wonder to what extent archaeology is the developer of such technologies, rather than the borrower." Absolutely, good scholars are often multi-disciplinary, so I think that you should always get a fair amount of symbiosis from talented individuals from many facets of the sciences. Also, having people from opposite polar extremes come together, helps to let people see different approaches to using devices/technology in a way or a manner in which an engineer, dentist may never have thought of and vice versa.

    Must say... I've enjoyed this thread today, although, shame on me for not having discerned the football pitch that Simon.d refers to in your quoted post. I'll go back and have another look.


  • Registered Users Posts: 69 ✭✭Briskit


    slowburner wrote: »

    Thanks for the gif but it should probably come with a health warning - you know, like when they warn about flash photography before a tv clip.:D

    Felt the exact same, but Simon.d then uploaded this link which rectifies this problem... and you can to and fro to your heart's content without experiencing a seizure :D

    Just use the left/right arrows to alternate


  • Registered Users Posts: 316 ✭✭Simon.d


    slowburner wrote: »
    Well if the technical wizardry here is anything to go by...who says archaeology is all dirt and sweat.

    Thinking even further into the future, I suspect a time will come when excavation will be looked back on with horror.
    Without doubt a technology will be developed which will give as much (if not more) information about a site, and without any form of destruction.
    I heard recently of a geo-physics technology which can detect the existence of buried human remains up to two hundred years old.
    It's something to do with the conductivity of the soil in the immediate area being altered by the decomposition of electrolytes in the corpse.

    I often wonder to what extent archaeology is the developer of such technologies, rather than the borrower.

    Definitely agree that destructive archaeology will be somewhat shunned in the future.. Even now it's difficult not to cringe when seeing something like this: 1328093544638.jpg

    I'm no expert on the technologies like GPR, magnometry, resistivity etc, but I'd be confident all the same that improvements in resolution, material identification and their capacity for 3d representation of what is being scanned is bound to improve in the coming years.. I also think improvements in the post processing of data acquired using such techniques could potentially aid in discerning some of this information, in a similar manner to which photogrammetric post-processing can portray topographical information hidden within photographic data.


  • Moderators, Science, Health & Environment Moderators Posts: 5,218 Mod ✭✭✭✭slowburner


    Simon.d wrote: »

    ...I'd be confident all the same that improvements in resolution, material identification and their capacity for 3d representation of what is being scanned is bound to improve in the coming years.. I also think improvements in the post processing of data acquired using such techniques could potentially aid in discerning some of this information, in a similar manner to which photogrammetric post-processing can portray topographical information hidden within photographic data.
    Absolutely.
    If you look at some of the print-outs from geo-phys surveys from 10-15 years ago compared to today, they look positively primitive (dot matrix printers :eek:).
    Having said that, I am a bit surprised at the relatively slow integration of advances in 3d visualisation technology, but I suspect a quantum leap is just around the corner.


  • Moderators, Science, Health & Environment Moderators Posts: 5,218 Mod ✭✭✭✭slowburner




  • Registered Users Posts: 316 ✭✭Simon.d


    slowburner wrote: »


    Would just love to go to that... Looks interesting..

    Just started down the road of kite aerial photography in the last few weeks, an even more affordable platform than the plane (€40), but more fiddly to get to grips with (so far).. Had the camera up at dusk only to date, so images aren't great.. Will hopefully see a bit of sunshine on a day off sometime soon!..


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  • Registered Users Posts: 1,020 ✭✭✭Coles


    Briskit wrote: »
    Felt the exact same, but Simon.d then uploaded this link which rectifies this problem... and you can to and fro to your heart's content without experiencing a seizure :D

    Just use the left/right arrows to alternate
    Does anyone know what mapping system is used in the second image on the above link? Many thanks.


  • Registered Users Posts: 6,700 ✭✭✭Mountainsandh


    There's a little double page in the National Geographic this month about Satelitte Archaeology. It focuses on the work of one arch, Sarah Parcak, University of Alabama at Birmingham, who has used it to identify previously unseen features in Egypt.
    "in 2011, relying on infrared satellite pictures, Parcak and her team identified 17 potential buried pyramids, some 3000 settlements, and 1000 tombs across Egypt." They have an example layered drawing of the city of Tanis.

    Nothing ground breaking in the article tbh, it's very short, but if anyone is interested I'm sure her crowd at the University must have released some more specific info on their work to date.

    p. 60 by the way !


  • Moderators, Science, Health & Environment Moderators Posts: 5,218 Mod ✭✭✭✭slowburner


    An interesting piece on photogrammetric modelling.

    http://www.ahiddenview.com/?p=814

    (by the way hypr3d has been taken over by a biz by the name of 'Cubify' and is no longer free, as far as I can see :()


  • Registered Users Posts: 316 ✭✭Simon.d


    slowburner wrote: »
    An interesting piece on photogrammetric modelling.

    http://www.ahiddenview.com/?p=814

    (by the way hypr3d has been taken over by a biz by the name of 'Cubify' and is no longer free, as far as I can see :()

    Noticed that the other day too :( ... 123dcatch (and a few others) are still free, and I'm finding it to be a superior service interms of deciphering detail. Downside with it is it tends to bring in some erroneous crack like features into the model, but not a major issue...


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