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"http://www.geod.nrcan.gc.ca"
Geodetic Survey is responsible for providing and maintaining the
national spatial reference system, standards and national networks of
gravity and survey control points for Canada. Geodetic Su rvey ensures
the availablility of spatial referencing information, exp ertise and
services that are responsive to the needs of clients.
Since confederation, one of the functions of the government of Canada
has been to provide a national system of surveys. From the Dominion
Lands Surveyors, who helped open the west, to the present, Canada has
always relied on a consistent national survey system as an integral
part of the national infrastructure. In 1909, the Geodetic Survey of
Canada was created by an order-in-council and given a mandate to
determine the positions (and elevations) of points throughout the
country with the highest attainable accuracy.
The primary role of the Geodetic Survey Division (GSD) today is to
maintain, continuously improve, and facilitate efficient access to
what is now known as the Canadian Spatial Reference System (CSRS). The
result is a national coordinate system which serves as a reference for
all mapping, charting, navigation, boundary demarcation, crustal
deformati on, and other georeferencing needs.
While continuing to serve on-going requirements for survey control,
the growing demands of Global Positioning System (GPS) users in
particular have resulted in a new focus for the Division, a focus on
supporting positioning from space. The Canadian Active Control System
(CACS) wa s established during this decade in order to provide users
of GPS with access to the national standard for positions. A real-time
capability under development, is expanding that access. In 1994,
development of the Canadian Base Network (CBN) was started to provide
a high accuracy network of ground monumentation compatible with the
increased precisi on available from GPS.
Gravity and Very Long Baseline Interferometry (VLBI) are key elements
of the program. While gravity observations satisfy geophysical needs,
they also serve as the basis for defining the geoid model. And the
geoid model, in turn, contributes to the vertical component of the
reference system so that ellipsoidal GPS heights can be converted to
orthometric elevations for practical uses. Finally, VLBI establishes
the stable fiducialIn developing and carrying out the geodetic
program, the Division coll aborates with scientific agencies such as
the International GPS Service for Geodynamics for international
standards and with stakeholders such as the provinces both for
national standards and for delivery of se rvices to clients. Contracts
are let to industry for operational requi rements, and research and
development initiatives are often directed t oward universities or
industry. The result is a Canadian Spatial Refer ence System that is
evolving rapidly with the integration of technolog ies of computers,
communications and satellites, to meet the diverse p ositioning needs
of the Canadian people. reference frame for the entire system, fixed
with respect to deepest space, and contributes to the evaluation of
crustal motion.
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