Since Manfred's arrival last week the Octocopter has been talk of the town. With its eight battery powered propellors, mounted digital camera, fully automatic stabilisation system which uses GPS signals to maintain an exact position and 'direct view' remote-control unit this high-tech gadget has impressed all. The Octocopters capability to take aerial pictures from precise positions above the site by flying a pre-programed flight matrix will allow topographic mapping and 3-D imaging over a large area.
Early morning rises to avoid windy weather (the only disadvantage of such a device) have been routine for Manfred and his assistant (all team members have been sacrificing breakfast and rotating as assistants). When the big black transport box has been lugged up the hill and the gear is set up its time for take-off!
The programmed flight matrix tells the Octocopter at which exact GPS position the images are to be taken, guaranteeing a minimum 70% overlap for all images. This means a single flight can include up to 160 individual positions! The electrically controlled mount for the camera holds the device in the selected position, mainly 90° for aerial images, automatically and feeds a live image to the TFT 'direct view' display held by the operator. Manual controls for flying the Octocopter, used for take-off and landing, as well as displays for battery power, GPS signal strength and link strength between remote and Octocopter can also be found on the remote-control pad giving the operator, in this case Manfred, 'constant peace-of-mind' or alternatively ordering him to land immediately because a crash is imminent.
After the brave assistant has literally 'caught' the Octocopter from the air (landing process) the battery-pack is changed and the next flight sequence can be prepared. 6 battery-packs allow roughly 1 hour of flight time. This and favorable weather has meant that almost the entire site has been covered over the last one and a half weeks!
Survey points, in form of regular white bathroom tiles, placed strategically on the surface being photographed, are measured with the Totalstation to give an exact coordinate reference for the images. These are then processed using computer software to generate a variety of images or maps. Also 3-D models of the site can be generated using the images taken by the Octocopter, in which every individual pixel has a coordinate that can be referenced. This mind-boggling amount of data is needed to create precise 3-D models and topographic maps.
This very exclusive work with Manfred and the Octocopter continues to be very rewarding for all as it's not everyday such a fancy device is employed on an archaeological excavation!