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Frequently Asked Questions

What is GPS?

The Global Positioning System (GPS) has become a widely used solution for surveying and other activities that require accurate geographic locations. GPS is a satellite-based positioning system operated by the United States Department of Defense and is used by both military and civilian users. Data collected through GPS is used for forestry applications, environmental studies, GIS database creation and maintenance, vehicle dispatching and many other applications. It allows users world-wide to obtain coordinates which are accurate to approximately 20m, or better. More accurate results require differential GPS (DGPS) positioning techniques to be used. This means the user requires two GPS receivers; one of the receivers must be capable of operating as a base station.

What is BCACS?

The Government of British Columbia, in cooperation with Federal agencies, local governments, Crown corporations and industry, is making it easier for users to collect, merge, and overlay geographic data by providing standardized, low cost and instantaneous positioning through the British Columbia Active Control System (BCACS).

The BCACS network comprises permanent, continuously operating GPS base stations which are linked via computer and telecommunication networks. These base stations provide data which allow users to correct the coordinates obtained with their single receivers to achieve positions accurate to less than 5 metres, or even less than 1 metre.

What BCACS real-time differential services are available?

The services available to provide real-time DGPS (digital global positioning system) corrections supporting all user needs, include:

  • Regional (coverage for British Columbia and surrounding areas, including all of Alberta) providing 1-10 metre accuracy
  • Municipal DGPS, providing centimetre to metre level positioning within urban areas
  • Canada-wide digital (CDGPS) service providing 1-5 metre coverage for all of Canada
  • An enabling environment for other value-added and integrated business solutions

What are the Benefits of a Municipal ACS?

  • Decreases maintenance (human and fiscal resources) over a physically monumented system - this applies for both Municipal and Provincial partners. The cost avoidance of maintaining and extending the present survey control monument base.
  • Supports other municipal programs (e.g., Intelligent Vehicle Location (IVL), E911 applications, Transit Authorities, etc.).
  • Provides a common GSR for all agencies with spatially positioned data (i.e. federal/ provincial/municipal and regional government; utility companies; private sector; etc.), supporting data sharing between agencies.
  • Avoids fragmented and single-purpose differential GPS service provisioning.
  • Improved accuracy, consistency, currency and completeness of positional information.
  • Ability to provide users with information regarding the integrity of the data.
  • Will enable the municipalities and the Base Mapping & Cadastre Section of GeoBC to fully meet the future requirements of GPS users with respect to timely and cost effective access to the GSR.
  • Will enable the realization of a precise and uniform provincial GSR consistent with modern spaced-based positioning technology. Will extend the relevance of the GSR more effectively to applications in geo-referencing, positioning and navigation requiring real-time or near real-time access.
  • Can help remove some of the cost barriers that limit the present utilization of provincial mapping standards by other organizations.
  • Will promote greater synergy between municipal departments through the provision of direct access to the positional framework of corporate databases.

What are the Phases in Implementing BCACSm?

BCACSm is undertaken as a partnership between municipalities and the Provincial government. As such, a Memorandum of Agreement is first signed between interested local governments and the Province. Components and phases of the implementation are:

  1. On line BCACSm Data Access
  2. Establish Municipal Active Control Points (ACPs).
  3. Establish BCACSm Post-Mission Service.
  4. Implementation of a Robust, Highly Accurate, NAD83 Control Network.
  5. Adopt NAD83 as Geo-referencing Standard.
  6. Re-adjustment and Adoption of New Provincial Vertical Datum.
  7. Implementation of a High Accuracy Geoid Model.
  8. Implementation of the BCACSm Real-time Service.
  9. Development and publication of BCACS and BCACSm Geo-positioning Standards and Municipal Application Standards.
  10. Testing demonstration and applications pilots
  11. BCACS augmentation

For further details contact the Base Mapping & Cadastre Section of GeoBC .

Who can use the BCACSm?

Anyone who needs precise positions can use the BCACSm. Positions accurate to 1 metre, or even to the centimetre level, are available instantaneously via a UHF radio link. Surveyors, engineers, mappers and others can effectively use the BCACSm for:

  • Land surveying - Cadastral surveys
  • Engineering surveys - as-built surveys, utility and infrastructure layout, inspections, etc.
  • GIS data collection - GIS pickup, thematic mapping, utility data capture
  • Police and Enforcement - incident analysis, tracking, spills, etc.
  • Fleet Management - vehicle routing, emergency response, fuels savings, time savings, etc.

How do I obtain GPS corrections for the BCACSm - CRD?

Differential GPS corrections are available for both real-time and post-mission applications from the BC ACSm - CRD.


Post-mission corrections can be accessed via Crown Registry and Geographic Base. Click here to complete an account.


To access the BCACSm - CRD real-time corrections; please contact the Capital Regional District at:

Peter Breen
Tel: (250) 883-1326

How do I configure Trimble Pathfinder?

Instructions for Configuring Trimble Pathfinder
Instructions for setting up Trimble Pathfinder Office to access BCACS RINEX files are provided in the document: BCACS - Pathfinder Office RINEX [PDF]
The FTP address format is included to eliminate the need to type this confusing address and to minimize typos. The codes for the Product and Station are included also.

More information