Laser scanners are routinely used for structural deformation monitoring, and
it's a piece of cake to use a reference system tied into a national datum.
Sadly (or otherwise) terrestrial photogrammetry is being rapidly replaced by
laser technology as a means of recording fabric, just when photogrammetry
was becoming affordable too.
Greg Jackman
PAHSMA
-----Original Message-----
From: George Myers [mailto:[log in to unmask]]
Sent: Wednesday, March 24, 2004 7:19 AM
To: [log in to unmask]
Subject: Re: Administrivia ( was Re: social sciences vs the bible?!)
One part of the "problem" is that the recordation and metrology requires
photography at the Federal level for HABS-HAER usually or tradionally in the
form of B&W 8"x10" records of photography. At the time it was thought that
the newer close-range photogrammetry might have a place as a bridge over the
"Why" of history. Unfortunately, I think, that hasn't changed and requires
special cameras and techniques to file officially, even though some of the
architecture contains many repeating elements.
Another part of the "problem" is the changing standards of digital record
keeping as we rush around getting different operating systems, using
different file systems (here comes Longhorn's MSFS designed in reponse to
database overload) and media for keeping records.
SOme of the laser scanning stuff is really interesting used in the San
Francisco Opera building going "where no man has gone before" (maybe the
Phantom of the Opera) into the structure supporting the beautiful domes. I
have looked at some of that construction in Tweed Courthouse in NYC. A
colleague was involved in the "Statue of Liberty" recording a number of
years ago, Ms. Tillar. My grandma was a nanny on Bedloe's Island for a
caretaker there back in the early 20th century. Unfortunately it's closed
until American Express can find enough money to reopen it because the
government is too cash strapped apparently.
Interstingly they had a "shoot out" in a couple of places between the laser
and the camera ("Starship Troopers" and an instiute for the study of
architecture in archaeology at Bryn Mawr University) and the topic seemed to
revolve around speed which of course one with a laser wins. However, it
depends on the subject of the study. The Metropolitan Cathedral of Mexico
City was being investigated photogrammetrically to determine the relative
movement of it's interior stone work from one time to another to perhaps
design a strategy to keep it intact or remediate "creep". I'm not sure a
laser scanner would be good for that, perhaps. The system I worked with
from Rollei, created the absolute coordinates of the film plan, from the
surrounding datums, perhaps the laser would rely on a datum that might be
recoverable at another time.
George Myers
----- Original Message -----
From: "geoff carver" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Tuesday, March 23, 2004 2:16 PM
Subject: Re: Administrivia ( was Re: social sciences vs the bible?!)
> You might want to look into the use of laser "scanning" theodolites for
some
> of this - check out the examples at (sorry, the page with the cool pix is
> only available in german):
> http://www.arctron.de/3D-Vermessung/3D-Laserscanning/Beispiele/
>
>
> geoff carver - SUNY buffalo
> [log in to unmask]
> http://www.thememoryhole.org/memoryblog/
>
> -----Original Message-----
> From: HISTORICAL ARCHAEOLOGY [mailto:[log in to unmask]] On Behalf Of George
> Myers
> Sent: Tuesday, March 23, 2004 13:46
> To: [log in to unmask]
> Subject: Re: Administrivia ( was Re: social sciences vs the bible?!)
>
> Well, to go back on target, it's interesting to be asked to record with
> close-range photogrammetry the church in Murray Hill, Manhattan, NYC. Each
> of the stone's faces were to be catalogued and conserved based on records.
> "As-builts" can be recorded from photos that provide real dat that can be
> measured out of the field. One use of it I've seen was a Canadian prairie
> church and sur ebeats trying to climb all over it with a tape measure.
>
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