High-Resolution, High-Accuracy Topographic Mapping Services
The Harris Geospatial Marketplace offers a top-of-the-line photogrammetric mapping service called “HiDEM”. This service involves collecting a pair of
stereo images to create high resolution, high-accuracy Digital Elevation Models
(DEMs). A team of experts with more than
25 years of photogrammetric mapping experience work behind the scenes on HiDEM
to deliver the best surface and terrain models in the industry.
Figure 1 Overhead View of HiDEM Data
Project Deliverables
- Key
Deliverables:
- 1 meter Digital Surface Model (DSM) data
- 5 meter Digital Terrain Model (DTM) data
- 1 or 2 meter Contour data (1m contours displayed
in above image)
- 0.5 meter Natural Color Ortho Image data
- Highly accurate at sub-meter RMSE vertical using client-supplied ground survey control points (GCPs
- Source Imagery: Pleiades-1, WorldView-2, WorldView-3 WorldView-1, & GeoEye
Why Use HiDEM?
HiDEM custom tasking is the perfect service if you need high
resolution and highly accurate elevation data for a project site. Below are a
few examples of how customers are using this data:
- Drainage and hydraulic projects, such as mapping
out sites to build a dam
- Mapping out sites before building a mine
- Mapping the area along pipelines for oil and gas industry
How It’s Done
Because end users will often have trouble sending a land
survey to his or her project area (due to large area size, difficulty accessing
the area, etc.), remote sensing is used. In this case, stereoscopic satellite pairs
are collected. With our HiDEM service, the points of objects on the ground are
determined by our photogrammetric team from the pair of images. Lines of sight
are constructed by finding the same points between the images, then determining
the three dimensional location of each through the intersections of these
lines. While the creation of the elevation model through satellite mapping is
similar across the imagery, there are processes and algorithms used by our
production team that make Harris Geospatial process unique.
The Harris Geospatial
Marketplace Advantage
While many companies create elevation models with comparable
resolutions, our hands-on approach delivers a more refined, better –quality end
product. Our photogrammetrists take the time to look over each model of a
project area to account for details that may have been missed. For example,
with a 5 meter resolution terrain model, a pipeline in a project area that is
say 4 meters in width would not show up in the raster image. A member of our
team would identify this detail and add break lines around the pipeline to
account for it. Many of our competitors generate terrain models automatically
which would miss key details like this one and create the potential for costly
problems down the road.
Additionally, our team will work with you throughout the
project to make sure nothing is overlooked at any point along the way. A project
manager will assist you in selection of ground control points (GCPs), defining
area boundaries, and identifying other details that need to be addressed. As a distributor
for all the leading satellite imagery providers with access to a large
constellation of sensors, we can facilitate getting your job done quickly and
efficiently, both in terms of time and money. Furthermore, with a large archive
catalog to choose from, we can find the best stereo pair imagery and deliver it
to you faster than a company who only works with their own satellites. All of these
factors mean that Geospatial Marketplace customers get the best elevation
models within the shortest time frame for the best value – hands down. Not a
customer yet? Talk to us to see how the HiDEM service can work for you.