Mleisa 1 Kite Orthophoto by Nathan Craig

Canon Powershot S90 KAP

This image accompanies a paper by Bibi et al. (2012) that was published in Biology Letters and is entitled “Early evidence for complex social structure in Proboscidea from a late Miocene trackway site in the United Arab Emirates”.
Here is a link to the paper:
rsbl.royalsocietypublishing.org/content/early/2012/02/22/rsbl.2011.1185 
The authors also established a website to accompany the paper. The link to this website is:
mleisa1.wordpress.com /
Here is information describing how the image was created:

Along the main concentration of tracks, a series of photographic targets was placed and measured to provide ground controls. Suspended in a downward looking gyro-stabilized mount, a Canon S90 camera was lifted by a Rokkaku kite. Using this equipment, parallel transects of overlapping (>30%) low-altitude vertical aerial photographs of the trackway site were captured. Photographs from this sortie were processed with the structure from motion photogrammetry application PhotoScan Professional to produce an image for measurement purposes. Lens distortion was estimated and corrected based on focal length and sensor size. On each individual image, reference points were established; between each image, reference points were matched. From these matches and the viewing parameters, the bundle adjustment was solved, and this provided an estimation of camera orientations and overall scene structure. Using PhotoScan’s height field routine, the surface geometry of the site was computed. The scale of this reconstructed surface was established from the measured ground controls visible in the photographs, and an orthographically corrected photomosaic was produced.