Sample Digital Orthophoto Images

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mardi 15 février 2011

Neolithic extraction pits of Ri (Orne, France)

In year 2008, the A88 motorway construction gave the opportunity to rediscover and excavate two hectares of flint extraction pits.

Just under the topsoil, the pits are not very deep, but they open into radiating galleries.

We were asked to carry out a 3D survey of the pits, using 3D laser scanning technology.

To provide a workable map of the surface, I produced this orthophotography, in which a section of the basement has been overlaid.

click to enlarge

vendredi 11 février 2011

Saint-Pierre medieval gate in Nantes

Last summer, I was called to carry out the 3D survey of the "Porte Saint-Pierre" in Nantes.


That was an interesting operation.

First because I didn't know Nantes, and the week I've spent there makes me feel that this town is a really good place to live.

I've met interesting people, talking about the use of 3D scanning, lidar survey and orthophoto in archaeology and architecture, and that was great to get the feedback on the data we produced.

The gate was not so easy to survey. Two of the 4 faces of the building are hidden by big trees so I had to use either a bucket truck and a telescopic mast to reach the best point of view for each photo and get a full coverage of the elevations.


For the 2 elevations that were easy to photograph, only 20 photos were used to get the good orthophotos. The 2 other ones required more than 170 images...

click to enlarge

mardi 8 février 2011

Unrolled column of the Great Hypostyle Hall of Karnak

Although the temple of Karnak is the second most visited monument in Egypt, the decoration of the 134 columns has never been surveyed.

Because of their shape, traditional techniques of representation couldn't be undertaken.

So, after discussion with Emmanuel Laroze, architect and director of the CFEETK (Egyptian and French Center for the study and conservation of the temples of Karnak), we decided to unroll them.

In 2007, we first completed the full 3D scan of the Hall and its 134 columns (3 weeks of measurement) : a pointcloud of 1 billion 3D points has been surveyed !

One year later, we achieved a complete photographic coverage of the columns (more than 4400 images).

Here is a result, produced in year 2005 from a preliminary test, undertaken to validate the method.

click to enlarge

vendredi 4 février 2011

Timimoun : The Red Oasis

Timimoun is located in the hyper-arid zone of the Sahara,1200 km southwest of Algiers.

To document the stand of the Algerian Ministry of Culture in the Second Panafrican Cultural Festival in Alger, we've been asked for Orthophotos and a 3D model of a nice mud building.

Everything has been 3D scanned and photographed, so we were able to provide any maps or 3D render.

Click to enlarge

See also a video of the 3D model here

jeudi 27 janvier 2011

Waste management site : terrestrial survey but aerial orthophoto

We used to survey this big waste management site twice a year with our long range 3D scanner (Reigl 420i at the beginning, then our Riegl 620).

The goal was to monitor settlements and to deliver accurate volumes.

 

An overview of the 3D mesh derived for our Riegl measurement

One day, our client asked us to fill up our maps with an orthophoto with a resolution of 5cm : we already had the DEM, we just lacked the photos. So we spent a day on the field, positionning big targets with our GPS, then we hired a little plane for an hour and we photographed the site with or Canon EOS I Ds Mark II (17 millions pixels).

Overall, that was easy to do, and a very cheap solution !

Click to enlarge

mercredi 26 janvier 2011

Conic unrolled orthophotography of a dam

In 2006, I've been asked to produce an orthophoto of a dam elevation than could be used to locate disorders in the concrete surface.

To maintain a relatively accurate distance measurement along the surface of the image, I proposed to use a cone as the surface of projection.

 

The Fabreges dam, its 3D mesh and the 3D model of the conical surface of projection

That was quite a special work, with lots of problems dealing with calibrating big telephoto lens, using very long range 3D scanner, programming specific orthorectification software. But there it is !

click to enlarge

The big red footprints have been painted by activists against the reintroduction of bears in the Pyrenees.

lundi 24 janvier 2011

Welcome !

Hi !

This is a new blog created to promote terrestrial orthophotography, and talk about the fantastic documents that are created using this technology.


I will try to tell about my experience about it, and I want to show you different ways to use orthorectification of calibrated images : aerial views, architectural elevations, archaeological maps, unrolled images.

So welcome to Orthophotography.net !

Mohammad Bin Saud first Mosquee

Founded in the 15th century, Atturaif was the first capital of the Saudi Dynasty, north-west of Riyadh.


The Unesco World Heritage Committee meeting in Brasilia has inscribed this site in July 2010.

In 2009, I've spent several months there to manage a full 3D scanning and high resolution photography acquisition and processing.

We delivered a high value-added graphical documentation to archaeologists and architects to feed the application to Unesco.

Mohamed Bin Saud first Mosquee : Click to enlarge

Traditional mud house elevation : Click to enlarge

Dinosaur footprints in Loulle (Jura, France)

A funny orthophoto of footprints leaved by dinosaurs 155 millions years ago.

Footprints have been painted by paleontologists to follow and study each seropod track.

Click to enlarge

Gavres Sand beach in Morbihan (France)

Here is an aerial orthophoto generated with a dataset acquired from terrestrial mobile 3D scanning and drone aerial photography.


Click to enlarge

dimanche 23 janvier 2011

Vieux archaeological excavation

A true orthophoto with a resolution of 2mm, covering archaeological excavation in Vieux-la-Romaine (Calvados, France).


More than 400 photos were taken with a nikon D200 + 14mm lens, mounted on a 3m high portable mast.
The site has been scanned with a long rang 3D laser scanner and the orthorectification has used a 3D model generated from a 12 millions 3D pointcloud.

The original image is 27000 x 12740 pixels.


((/public/archaeology/vieux_mini.jpg|Archaeological excavation in Vieux (Calvados, France)|C|Archaeological excavation in Vieux (Calvados, France), Jan 2011))

Click on the image to enlarge

Sommieres Roman Bridge

The main road bridge into Sommieres was built in the years 19 to 31 for the passage of the Roman road from Nimes towards Toulouse and Lodeve.

Built as a 17-arch bridge, 189 m long, there are today only 7 of the arches still visible. The others have been swallowed up by houses constructed at the ends of the original bridge. 

This image shows how the town has settled on the bridge during middle age period.


Click on the image to enlarge