Monday, April 09, 2007

NY Times "Beaming Up 3-D Objects on a Budget"

I once worked with archaeologist Joel W. Grossman, Ph.D., (Berkeley Ph.D. on Peruvian prehistory) who was a 3D innovator in archaeology. We had a 3D stand in beta with "joy stick-like" potentiometers to digitize ceramic sherds, which at the time were then "completed" for example to determine volume. He also had a circular disc built on a tripod to photograph deposits that were then 3D slides for viewers of the "Augustine Heerman Warehouse" in old New Amsterdam also photographed with an overhead bi-pod holding a camera next to Whitehall Street in lower Manhattan during the winter excavations in early 1980s. A similar bipod (or monopod?) was used by the French "Museum of Man" to document the excavations in the hydroelectric project in Uruguay investigated by my Welsh/Uruguayan classmate, Mary FitzHerbert, continued by a Fulbright scholar who reported on southeast research in "American Antiquity".

In the late 1980s early 1990s I was involved with Joel Grossman again and then he was working with Prometric Technologies, now of Markham, Ontario on the 3D close-range photogrammetric recording of archaeological features using the Rolleimetric MR2 system, also used in accident reconstruction, building "as-builts", petroglyph recording (one a spiral around a basalt column next to a precipice created after the depiction, another I speculate might be the "Little Bighorn" recorded from the native's perspective in Moosejaw, Canada where Sitting Bull fled), to document the movement of stonework of the Mexico City Metropolitan Cathedral built on top of an Aztec ceremonial center, perhaps, and other metrology especially as we were involved in the archaeological evaluation and recording in the EPA's National Priority Superfund cleanups, it was seen as a tool for least contact method of recording. As a tool it's what you want to know however that makes it useful.

Sometimes, a few of the RFP's I've heard about that have been sent out requesting estimates, require that the company not just do the "standard job" but require some new "spiffy" ("sexy") new advancement in the "discipline" in order to be given the work. Some of these never were part of the final design plan, as the researched exposure levels, objectives and politics change the underlying assumptions, creating other situations.

I'm not sure how 3D is applied in other work. I worked in AutoCAD since it became 3D and it was part of our reports using State-Plane coordinate info from transit readings, a standard used by surveyors for the clients in the US. Getting them might be difficult. One of the problems in archaeology is getting "aerial" coverage of the area(s) of impact especially in a construction impediment situation, to provide adequate documentation of efforts and descriptive explanation for evaluation and review. Sometimes that has meant putting someone in a backhoe bucket and trying to photomosaic the series of photos one hoped overlap enough, without depth of field, etc., interfering with the effort. Rollei had a pneumatic monopod that used compressed air to raise the height of the camera for that kind of description and their photogrammetric system was also tested by marine archaeologist of the NOAA, Erv Garrison, and reported as one of the techniques available in an article he wrote. Another interesting demonstration I saw was by the photographer Ken Hansen whose constructed a monopod made of nested square tubing within which were pulleys and steel cable, enough to lift a then standard television broadcast camera up to a height of 30' with video feed to pan, tilt and point it. Apparently some of the "only" video from the first siege of Baghdad, Iraq came only through this method from behind and over the top of the US Embassy wall which I think was why it was designed, to be sent there. Prometric had a similar setup, in that a small video camera and feed from a 12V battery showed what was seen through the medium format camera lens, pointed by a fairly weak however electrical pan-and-tilt attachment. Reseau plate and photo integration (film is held against the glass plate during exposure) however, in software "works" mathematically better in a series of additionally oblique exposures to the subject to create the "3D" virtual reality. (See "Reseau Plate" used on the Moon in Wikipedia) Posted to histarch 4/09/07

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