Services : Digital Photogrammetric Mapping

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Over the years, we have played a key role in the development of accuracy and content specifications, workflows, procedures and training programs for several major private, public and military agencies in Canada, the USA and abroad. This expertise can be called upon, as required, to define optimum specifications for the mapping component of your projects.

Whether your project requirements involve full or partial planimetric feature data, DTM products, contour data and/or volumetric data, we have the tools and the expertise to provide the most reliable, cost-effective production available. FME file conversion and/or proprietary in-house software is used to deliver problem-free data in the format and structure of your choice (i.e.: DGN, DXF, DWG, KDMS and ESRI).

For final products, the photogrammetric model data is merged into map sheet format. Appropriate symbology, patterning and text edits are applied to enhance the cartographic quality of the product. Custom sheet layout and map surround design are also available to provide you with digital and hardcopy mapping products that will complement your presentations and add an element of visual clarity to the relevant issues in your project meetings.

Below, is information on:

• Planimetric Feature Compilation with Digitized Contours
• Digital Terrain Models (DTM)
• LIDAR Enhancement Editing

Planimetric Feature Compilation with Digitized Contours

The following production screen shot illustrates the ZI SSK Pro stereo-compilation environment, in dual 21" monitor configuration. Both monitors operate with stereo display and variable zoom definition for each view.

At AMT, we produce only the highest quality planimetric feature and contour data. Regardless of the scope of your project, all work will be completed with strict adherence to accuracy, content and procedural specifications.

Excellent interpretive skills, focused efficiency, thorough QC procedures and a solid knowledge base are the cornerstones of our production processes and the reasons for our continued success.

Digital Terrain Models (DTM)

A Digital Terrain Model (DTM) is an accurate, 3 dimensional representation of the surface of the ground, and is comprised of breaklines captured at all significant changes of slope and discrete profile points captured at a density suitable to the defined product.

Optimum profile point density depends upon photo scale, base product scale, contour interval, and the relief of an area and the nature of the specific project. While a dense grid of points is generally desirable in areas of undulating relief, too dense a grid can be problematic in very flat areas causing the generation of cartographically unacceptable depression and isolation contours. A grid of points that is too dense can also cause unacceptable contour anomalies in steep areas due to argumentative elevation data (profile points captured too close to breakline data).

DTM data sets are used to produce accurate triangulated surfaces, contours, profile lines, cross-sections and rectified digital orthophotography.

AMT personnel have been actively compiling reliable DTM data since the development of this approach in the early 1980's. All DTM data sets undergo rigorous quality control and edit through the stereoscopic review of DTM data and online-generated contours. These QC procedures ensure that our DTM data will produce consistently reliable and cartographically acceptable contours.

LIDAR Enhancement Editing

Stringent DTM QC services with online contour generation are also applicable for final stereoscopic review and edit of LIDAR produced data. In this edit, the accuracy of discreet elevation points is reviewed and point data is edited as required. Breakline data is added to the data set, where required to maintain the accuracy and cartographic acceptability of generated contour data. These services are available to LIDAR providers in an effort to embrace the ever-advancing technologies of today's mapping sciences.