CTI currently distributes different digital products, each meant for a specific use.
Since every user has his own needs, the product should be chosen according to the best requirement available.
The following advice can help you decide which products to choose.
Advice on Choosing Digital Products
* Digital topographic data discrepancies
are subject to a discrepancy process.
National Topographic Data Base (NTDB)
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The National
Topographic Data Base (NTDB) comprises digital vector data sets that cover the entire Canadian landmass. This
product includes thirteen themes such as hydrography, hypsography and the road network (see also the Updated Road
Network product [URN]). The NTDB is a complete and uniform product that can be highly useful in a broad range of
activities. For example, it can be used for preparing thematic maps and makes it suitable for geographic
information system (GIS) applications because the NTDB and its attributes make it possible to use spatial analysis.
VMap0
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VMap0
database is designed to provide vector-based geospatial data at low resolution. The content of
the database is similar to the previously published Digital Chart of the World (DCW). This
vector product at the 1:1 000 000 scale covers the six continental regions of the world.
This database is excellent sources of base information for all aspects of global monitoring as well as for studying
and developing research methods in geography, spatial analysis, earth sciences, social sciences, resource, management
and communications. It provide a base for an unlimited number of value-added spatial overlays.
NTDB Correction Matrices (CORMAT)
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The NTDB Correction Matrices (CORMAT) is a product derived from the planimetric enhancement of NTDB data sets at the
1:50 000 scale. The correction matrices enable users to enhance the geometric accuracy of the less accurate NTDB.
Toporama
A new and improved Toporama is moving to the Atlas of Canada in early 2006 -- Read more about the features.
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Toporama is a site that provides
easy Internet access to free topographic images of Canada. It can serve for applications such as word processing and
drawing/image software. Just select an image, copy it, and paste it into your desk application, or select an image and
copy to disk. This product is a great way to give family and friends directions for getting to your home or cottage.
Toporama also has applications in geography and mapping: as a background map to which other information can
be added or to locate topographic features such as towns and lakes. It uses representation features such as symbols,
screens, and colors similar to a topographic paper map. Simple navigation tools and a legend are provided to make it
easier to find your way around. Finally, there is a series of index cards that users can consult to guide them to the
area for which they want images.
Canada 3D
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Canada3D is a digital
elevation model (DEM) consisting of an ordered array of ground elevations providing coverage of the entire Canadian
landmass. Canada3D is available in two forms: grids regularly spaced at 30 or 300 arc-seconds. DEMs have assumed a
major role in digital mapping. They are used in geographic information systems (GIS) for land-management applications.
Moreover, they play the same role as contours and relief shading on conventional paper maps but offer greater analytical
potential. DEMs can also be used for terrain modelling, for calculating the influence of the terrain on line-of-sight,
for radar imaging, for simulating flooding, and similar applications.
CanImage
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CanImage is
an image composed of three spectral bands originating from resampled Landsat 7 orthoimages. They are chosen
by the user based on the National Topographic System (NTS) at the 1:50 000 scale. This product is distributed
in GeoTIFF format.
Data acquisition dates can vary between scenes. Image content may differ from reality.
For example, roads built after the scene acquisition date will not appear on image.
Spectral bands have a pixel size of 15 m.
The files can be opened in different applications in response to specific needs: geographic information
systems (GIS) for land management applications; mapping software to visually represent a region; remote
sensing / digital image processing software and their algorithms (classification and other) to detect
topographic entities (vegetation, hydrography, roads, vegetation-free surfaces, etc.), different types of
crops and vegetation species, and so on.
CanMatrix
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CanMatrix raster data
is produced from scanned maps of Canada at the 1:50 000 and 1:250 000 scales. The Centre for Topographic
Information wants to create a national database composed of raster map data where each pixel has a distinct geographic
location (georeferenced data). Since CanMatrix is an image, it can be used as raster backdrop for various applications,
such as raster maps for Global Position Systems (GPS).
IRS
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The IRS
satellite data is reserved for federal government agencies and organizations as part of the federal government's
Emergency Preparedness Program. The orthoimages were produced with data from the Indian Remote Sensing (IRS)
satellite. The coverage is restricted to Canadian cities with a population of 25 000 or more.
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