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.