December 25th, 2012
Back in May we processed an interesting data set from Easter Island, Chile at 30 cm / px GSD. Kim Anh Hoang from the Easter Island Statue Project used the 30 cm Orthomosaic and DEM to produce a 3D Flyby of Rano Raraku and an EISP excavation site. We've now re-processed the data at the highest resolution possible, 15 cm / px GSD. The original imagery was obtained using an autonomous UAV flying at an elevation (AGL) of ~330 meters with a consumer level Ricoh GR Digital III camera. The GR Digital III is not GPS enabled, so geo-tagging was accomplished locally using the UAV flight controller logs. In total, 140 NADIR images were shot at 10 mega pixel covering an area of 3.7 km^2.
"Rano Raraku is a volcanic crater formed of consolidated volcanic ash, or tuff, and located on the lower slopes of Terevaka in the Rapa Nui National Park on Easter Island. It was a quarry for about 500 years until the early eighteenth century, and supplied the stone from which about 95% of the island's known monolithic sculptures (moai) were carved. Rano Raraku is a visual record of moai design vocabulary and technological innovation, where 397 moai remain. Rano Raraku is in the World Heritage Site of Rapa Nui National Park and gives its name to one of the seven sections of the park." Rano Raraku - Wikipedia
A map of Easter Island/Rapa Nui, showing the three main volcanoes Terevaka, Poike, Rano Kau, as well as Anakena beach, the islets including Motu Nui. Modern Hanga Roa and Mataveri International Airport, the ruins at Orongo and the quarry at Rano Raraku. It marks major ahus with moai.
Above we've displayed a small subset of 8 images from the original 140. We recommend obtaining more overlap and imagery for an area of interest (AOI) this size.
Contact Us for the full geo-referenced downloadable data set.
Comments
Hi, old blog post I know, but I just watched "MYSTERY OF EASTER ISLAND" on NOVA. Was that your work featured in the show - used to find ancient road beds used to move the moai?
Nice! Perfect.
JP, thanks by your interest!
Yep. When controlled by the ArduPilot the shooting session will be commanded by the mission. So it starts and stops on given waypoints. Also is the mission who tells the capture rate. =)
Hi Sandro! The device you are building sounds awesome and very useful, I can't wait to check it out when completed. Maybe you could have the device just trigger the camera when the flight platform is over the area of interest (AOI).. this would be a nice time saver during the 'data clean' up phase of a mapping mission. essentially it would eliminate imagery that you don't need for post processing: Non-AOI, Take off, Landing, Turns (???)
That's really cool JP!
Those cameras are very light and powerful. I'm working on a small board that controls Ricoh cameras from ArduPilot telemetry port and also from a RC channel. My goal is a set of commands for enabling the camera, controlling the shooting session and disabling it for landing.
Hi all, thanks for the comments. The imagery was shot every ~4-5 seconds with an AGL of around 300m. Unfortunately, I don't know many details about the camera setup as the original 2D imagery is from a Gatewing UAV. I assume it has a USB trigger like mentioned above, that would make the most sense.
Hi there, my understanding is that the Ricoh GRD III could be triggered from the USB with no hack. Do you confirm it? I also use this camera with Gatewing X100, and I am just wondering if the camera's firmware has been modified for it or not.
Happy landings. Rodolphe