Canadian Active Control System (CACS)

The Canadian Active Control System (CACS) consists of national and regional networks operated by CGS and other public agencies.  Each CACS monument is anchored to bedrock and all tracking stations are equipped with one or more GPS/GNSS multi-frequency receivers. The stations continuously record high-rate pseudo-range and carrier phase observations from all satellites in view. Some stations are also equipped with meteorological sensors measuring atmospheric pressure, temperature and humidity.

Stations of the Western Canada Deformation Array (WCDA) operated by the Public Safety Geoscience program of Natural Resources Canada monitor crustal dynamics along the Cascadia subduction zone. Access to CACS station data, including contributions from the WCDA and Nova Scotia ACS, is provided through the CGS web site. Users can download station descriptions and data archived at 1 sec or 30 sec interval from the NRCan CACS web interface.