Exercise for apprentice photointerpreters (click images to embiggen)

[fivemack]

This photograph, students, was taken at 1238 Dubai time on March 13th from seat 47A of Emirates flight 763, which had taken off from Dubai airport en route to Johannesburg almost exactly two hours earlier. The aircraft was proceeding southwards oven the Yemen at approximately 900kph at an altitude of ten thousand metres; our operator used a 27-millimetre focal length lens on a Nikon D50, and the aircraft crossed the coast between al-Hajaf and al-Bahiyah approximately twenty-one minutes later. Today's exercise should be no great problem for you: find the confluence of river canyons at the bottom on Google Maps, and tell me how you did it.

Once you have given up in frustration, marvel at the strange things one finds in the desert; this picture was taken about twenty minutes after takeoff, the point of the teardrop is at 24.144N 55.923E, near the UAE/Oman border at the town of Al-Ain - note that there's nothing on the Google map in that location, though a good deal on the satellite picture. There's been a fair amount of new construction since the Google Maps satellite image was taken)

and the amazing shapes of the terraced hills of Ethiopia (taken about an hour after the Yemeni canyon image, and looks as if it must be somewhere around 9.7N 42.5E, but the season's different on the Google Earth images of that bit of Ethiopia and I haven't a clue how to make a more exact match)

Comments

[dd-b.livejournal.com]

Draw the great-circle track between takeoff point and coast crossing. Test the speed against that track, making some allowances especially at the beginning. If it passes sanity check, back off from the coast (the nearest fixed point) the measured time.

Determine which side of the aircraft the seat is on. Guestimate the camera down-angle; figure where the center of the frame would be based on this and the track. (This may be a waste of time, as the accuracy of the track may be low enough that this correction is irrelevant.)

Calculate the size of the feature from the distance and focal length and sensor size.

Select topographic mode in Google maps. Zoom to a scale where the feature size will be about the same as in the photo.

Orient the photo to match the map orientation.

Look around the area for matches.

Eventually, give up in frustration.

(Sorry, I've got time to speculate briefly, but not time to actually see how it works; work, and Minicon this weekend, are killing my time.)

[twoeleven.livejournal.com]

I'd be tempted to skip Google maps and use a high resolution GIS set containing just water features. The wadi juncture looks distinctive enuf to find knowing only the rough location. I happen to have such a set, but I won't have look until at least the weekend.

[naath.livejournal.com]

In future send GPS unit with photographer :-)

Lovely pictures. Amazingly clear for things taken from a plane.

[movingfinger.livejournal.com]

[Friendsfriends cruising]

There are several sites that can give you real-time flight tracking; at least one of them renders the flight path over GoogleEarth, but I can't remember which that is. As far as I know, the sites don't store the path, so if you can find one that renders it on a field with a useful amount of information and watch the flight next time it goes, you may be able to narrow your search area down.

Your big problem is probably that detailed topo information for the Middle East and Africa on the web is nothing like that for Switzerland or even the USA.

I love aerial photography. Your photo of the terracing in Ethiopia is fascinating.

[downybearded1.livejournal.com]

Oooh, the third image looks so fractally *drools in happiness*