Borstad Associates Ltd. - Data sources (descriptions from the various web sites)

Data sources (descriptions from the various web sites)

One of the major findings from the watershed study was that some of the watershed management organisations already use satellite imagery, but the majority reported that “satellite data are expensive, difficult to use and require expensive software and extensive staff training”.

This section addresses the cost of satellite data. To ensure accuracy, the description of each satellite data product has been copied from the various web sites.

GeoGratis is a web and file transfer protocol (ftp) site that distributes geospatial data of Canada. Data are available for download, without charge. Vector mapping data are available in scales ranging from 1:50,000 to 1:30,000,000 in a variety of file formats. Not all vector layers are in all scales. Similarly, several types of full resolution satellite imagery are on-line. Please note that some files are large (single bands may be 55 MB), therefore plan to download outside Eastern Standard Time peak hours (a high speed connection >100 KB/s is preferable).

There are several methods to access GeoGratis data. It is recommended that clients go through the menu driven mechanisms on the left (of the home page). Data selection tools, format translation services as well as the online metadata are encompassed in this manner of access. The data collections on GeoGratis are also available through the: GeoConnections Discovery Portal.

Many clients who download large volumes of data prefer the functionality of FTP. There is also direct 'data archive' access.

GeoBase is a federal, provincial and territorial government initiative that is overseen by the Canadian Council on Geomatics (CCOG). It is undertaken to ensure the provision of, and access to, a common, up-to-date and maintained base of quality geospatial data for all of Canada. Through the GeoBase portal, users with an interest in the field of geomatics have access to quality geospatial information at no cost and with unrestricted use.

GeoBase responds to Canadians' requests for access to data at no cost to users. It is built on partnerships and innovative technology. By working together, multiple levels of government are increasing their efficiency in collecting and maintaining geospatial data. This also reduces duplication of efforts among agencies.

By creating the GeoBase portal, the partners are also improving Canadians' access to:

Administrative Boundaries
Canadian Digital Elevation Data (CDED)
Canadian Geodetic Network
Geographical Names of Canada (toponymy)
Landsat-7 Orthoimage
National Road Network (NRN)

GeoBase data has been produced and is available in accordance with established national standards and includes explicit metadata to facilitate its use. GeoBase data provides reference, context and underpinning to a wide variety of thematic data for government, business and individual applications. Canadians will not only benefit from access to data, but also from ongoing geospatial data updates, that will be delivered through the GeoBase portal.

The resolutions of available GeoBase data are:

between 1:10,000 to 1:250,000 scales for the Regional themes; and,
between 1:1,000,000 and smaller for the National resolution themes, available in the near future.

GeoBase is a key component of the Canadian Geospatial Data Infrastructure that has been promoted and facilitated through GeoConnections. The GeoConnections program has provided significant funding for the preparation of, and accessibility to, GeoBase data and the GeoBase portal complies with GeoConnections' vision and principles.

Easy to use index maps provide Landsat path/row or NTDB map sheet number for areas of interest. The data are emailed as zipped file within hours. The path/row identification facility in GeoGratis is also useful when using path/row to identify Landsat scenes for down load from the University of Maryland site.

GeoBase users are provided with links to a few no cost viewers. GeoBase does not endorse nor does it provide support for any of these viewers. Typical viewers for data in Shape format include:

http://www.esri.com/software/arcexplorer
http://www.mapmakernorthamerica.com
http://www.digitalgrove.net/fgis.htm
http://www.vividsolutions.com/jcs

Similarly, for viewing for CDED data:

http://www.pcigeomatics.com/freeware/freeware.html
http://mcmcweb.er.usgs.gov/drc/dlgv32pro/index.html

The Earth Science Data Interface (ESDI) is the Global Land Cover Facility’s (GLCF) web application for searching, browsing, and downloading data from the University of Maryland’s online holdings. http://glcfapp.umiacs.umd.edu:8080/esdi/index.jsp

If you are looking for Landsat data, use the Path/Row Search if you know the paths and rows for your area of interest (see GeoBase above). You can also use the Map Search to browse and query using an interactive map. You must use the Map Search when looking for Landsat Mosaics.

National Topographic Data Base (NTDB)	Updated Road Network (URN)
Canadian Digital Elevation Data (CDED)	Toporama
Administrative Boundaries	CanImage

The Centre for Topographic Information (CTI) distributes a range of spatial data products that may be useful to the watershed manager. However, there is often a charge attached to the service. For instance, municipal boundaries for all of Ontario cost $1,874+taxes with the price for boundaries of individual municipalities ranging from about $10 to $100+taxes. There is a minimum service charge of $25+taxes, even when the data set is “free”.

The full list of products can be found on the CTI web site. Only those needed to fulfil the tasks specified earlier are described here. As an example, the prices are provided for NTDB coverage of the Ottawa area at 1:250,000 map (031G) and the 1:50,000 (031G05).

“High speed” Internet connections with typical transfer rates of 116 KB/s were used to down load data from FTP sites. A single Landsat-7 band is about 55 MB and took about 6 minutes to download from GeoGratis. A CanImage 9.2 MB zipped file containing an RGB Landsat-7 image corresponding to a 1:50,000 NTS map area took about 1.5 minutes to down load.

National Topographic Data Base

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.

031G $414.32+taxes 031G05 $538.89+taxes

Individual themes and their prices are listed under the “metadata” button”. Each theme can be purchased separately for between $0 and about $130+taxes.

Canadian Digital Elevation Data

The Canadian Digital Elevation Data (CDED) comprise raster data from NTDB contours at the 1:50,000 and 1:250,000 scales. These data are used in geographic information systems (GIS) for land-management applications. In addition to providing estimated values of elevation points, CDED can be used to determine orientation and slope of each point when used in GIS applications. CDED can also be used for terrain modelling, for inter-visibility studies, for satellite image rectification, for flood simulations, etc. For example, in telecommunications, CDED can be used for wave propagation studies.

031G $0 031G05 $0

Administrative Boundaries

The Administrative Boundaries comprise digital data sets represented by lines and areas. Each file (data set) contains six types of entities: international boundaries, provinces, municipalities, national parks, national wildlife areas, and migratory bird sanctuaries. A total of 13,351 files at the 1:50,000 scale and 980 files at the 1:250,000 scale are created for the entire Canadian landmass.

031G $87.47+taxes 031G05 $8.53+taxes

Updated Road Network (URN)

The Updated Road Network (URN) files comprise updated digital vector data sets that will cover the entire Canadian landmass. The URN provides a base of properly structured vector data (like with NTDB) designed and suited for geographic information system (GIS) applications.

The URN data are recognised as equivalent to those offered at no cost, since November 19, 2003, on the GeoBase portal under the National Road Network (NRN) theme. Since then, they are also distributed at no cost on the CTI Web site, with the exception of the $25 minimum charge per order.

As GeoBase data are intended to replace equivalent NRCan data, the URN will soon cease to be distributed on the CTI Web site, this gradually as NRN data are made available on GeoBase. We thus encourage you to look into the data specifications and the download functionality of the GeoBase portal.

031G not applicable 031G05 $0

Toporama

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 colours 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.

031G not applicable 031G05 $0

CanImage

CanImage is an image composed of three spectral bands originating from resampled Landsat-7 orthoimages. The bands and projection (e.g. UTM or geographic) can be are chosen by the user and areas are based on the National Topographic System (NTS) at a 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.

031G not applicable 031G05 $25