TOOLBOX /
distance meter. The EDM was the
replacement for the steel tape. At first, the
EDM’s were stand-alone units mounted
on tripods and powered by car batteries.
As they became smaller, they were
mounted on top of a theodolite, and then
angles and distances could be measured
simultaneously. This connection would
soon be transformed into what is called a
total station. This electronic instrument
can display angle and distance readings.
As total stations evolved, they began to
do the trigonometry involved by reducing
the measurement from the raw slope
distance to the more useful horizontal
and vertical distances. They next began
to include a data collection feature so
transcription errors could be avoided very
helpful considering the volume of shots
typical to a topographic survey. Over the
past few years, robotic instruments and
BSLA
some models with a built-in laser scanning
capability are features in top-of-the line
in surveys. In the past, a typical project
involved a basic drafted topographic
survey showing contours, spot grades,
and the main site features and would be
drafted on vellum, linen or mylar. Modern
products produced now range from raw
3D point clouds, 2D plans or advanced
3D models based in Revit and other BIM
software. The change brought about by
computer technology has driven most
of the differences currently seen in the
surveying profession.
Lidar, or laser scanning, has entered the
mainstream of surveying practices. One of
the first laser scanners made for the AEC
market, the Cyrax 2400 (manufactured
by Cyra Technologies now owned by
Hexagon), was envisioned to aid in the
Boston Society of Landscape Architects Fieldbook
11