Topographic Mapping
& Digital Terrain Modeling
What’s your application …1/4 foot contours
for highway reconstruction, 1’ contours for sewer
expansion or a Digital Terrain Model (DTM) for watershed
analysis?
Whatever your application, Axis GeoSpatial can apply
the appropriate technology to provide you with the most
accurate elevation data. For contour data, through our
eyes we will collect 3D breakline and masspoint data
in our softcopy stereo workstations to accurately portray
the terrain. Once the DTM has been collected, we then
can generate contours at the required interval to provide
you the detail necessary for your application.
For applications requiring Digital Elevation Models
(DEMs) of larger areas, Team Axis GeoSpatial can fly,
produce and post process DEMs through the use of LIDAR
technology. Various processes can be performed on the
raw LIDAR data such as vegetation & structure removal
or breakline supplement in a stereo environment …whatever
your requirement, Team Axis GeoSpatial understands.
Dispelling the Myth…
If you are a potential purchaser of LIDAR services or
data, please do your research. Seek out unbiased studies
and papers on LIDAR data from unbiased sources. LIDAR
technology is in it’s infancy and many “LIDAR
Companies” out there are still trying to figure
it out. Their unqualified salespeople will tell you
whatever to make a sale as they are being pressured
to keep their very expensive equipment utilized. The
final results are what you should be concerned with.
Understand that LIDAR data, as all technology, has
its limitations. LIDAR technology is being developed
and perfected every day and the relative accuracy and
point density is increasing, but RMS accuracy does not
translate into 1 & 2 foot contours. If you need
contours which accurately portray the terrain, understand
the LIDAR data must be put through certain processes
to allow accurate contour generation. Accurate contours
can only be produced from a DTM, not a DEM and there
is a significant difference. Just because the RMSE of
a particular LIDAR DEM is around 15cm does not mean
it will produce reliable and accurate 1’ Contours
for certain applications. If you’ve been hearing
LIDAR, you’ve probably already heard such claims
by novices in the industry. Anyone with any TIN software
can generate any contour interval from any DTM or DEM
…don’t choose just ‘Anyone’
to provide you data produced from this very complex
technology.
|