Daily Archives: July 2, 2013

Laser imaging of Sitka poles

Lidar model merged with photograph to document carved pole, Sitka, Alaska.  Source: NPS.

Lidar model merged with photograph to document carved pole, Sitka, Alaska. Source: National Park Service.

This is an interesting application of Lidar technology – creating a durable, highly precise, digital image of a standing pole, which can then be wrapped with high-resolution photographs and used in a “virtual tour” context. It can also be  an archive for conservation.  The project is underway to record a couple of dozen Tlingit poles in an outdoor setting in Sitka, Alaska.

Lidar stands for “light distancing and ranging” and is basically like radar or sonar, only using laser beams.  Thousands of individual laser bursts can measure the three-dimensional surface of something like a totem pole to accuracy of a millimetre or less.  This creates an accurate digital record of the shape of the pole which can then be rendered on-screen in various three-dimensional ways.  Lidar has seen a fair bit of use in archaeological survey (especially its ability to digitally clearcut the trees) and also has seen quite a bit of table-top use to record artifacts in exquisite detail.  The “meso-scale” recording of features like poles is less common though, especially outside of historical and classical archaeology.  There is a lot of potential for recording petroglyphs I think — for example this recent dissertation (which I need to order) apparently shows proof of concept at Writing-On-Stone in southern Alberta.

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