The Unofficial Home Page of
Canadian Geodetic Networks
Michael Craymer, Ph.D.
Coordinator, Reference Frames & Earth Dynamics
Canadian Geodetic Survey, Natural Resources Canada
588 Booth Street, Ottawa, Ontario K1A 0Y7, Canada
Tel. 613-791-0157, Fax. 613-995-3215
Last revised 2015-10-24
- International Terrestrial Reference Frame (ITRF)
- World Geodetic System 1984 (WGS84)
- North American Reference Frame (NAREF)
- GNSS Reference Frames
- Canadian Active Control System
- Canadian Base Network
- Adjustments & Analysis
- Geodetic Software
- Other Links
- WGS 84 (G730 & G873) - Department of Defense World Geodetic System 1984: It's Definition and Relationships with Local Geodetic Systems,
Third Edition, Ammendment 1, National Imagery and Mapping Agency Technical Report TR8350.2, 3 January 2000.
- WGS 84 (G730) - Maintenance and Enhancement of the World Geodetic System 1984,
by Malys and Slater, Proceedings of the 7th International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GPS 1994).
- WGS 84 (G730) - Improved WGS 84 Coordinates for the DMA and Air Force GPS Tracking Sites,
by Swift et al., Proceedings of the 7th International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GPS 1994).
- WGS 84 (G873) - Refinements to The World Geodetic System 1984,
by Malys et al., Proceedings of the 10th International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GPS 1997).
- WGS 84 (G1150) - A Refinement to the World Geodetic System 1984 Reference Frame,
by Merrigan et al., Proceedings of the 15th International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GPS 2002).
- WGS 84 (G1150) - Addendum to TR 8350.2: Implementation of the World Geodetic System (WGS 84) Reference Frame G1150
- WGS 84 (G1674) - Recent Updates to the WGS 84 Reference Frame,
by Wong et al., Proceedings of the 25th International Technical Meeting of The Satellite Division of the Institute of Navigation (ION GNSS 2012).
- WGS 84 (G1762) - Department of Defense World Geodetic System 1984: Its Definition and Relationships with Local Geodetic Systems,
National Geospatial-Intelligence Agency (NGA) Standardization Document NGA.STND.0036_1.0.0_WGS84, Version 1.0.0, 2014-07-08.
- World Geodetic System 1984 (WGS84),
UN Office of Outer Space Affairs, International Committee on Global Navigation Satellite Systems (ICG)
IAG Sub-Commission 1.3a: Regional Reference Frames - North America
Other Regional Reference Frames
GNSS Reference Frames
Compiled by International Committee on Global Navigation Satellite Systems (ICG),
UN Office of Outer Space Affairs
- The Evolution of NAD83 in Canada (Craymer, 2006).
The definitive source for transformation parameters between NAD83(CSRS) and all versions of ITRF.
- Transforming Positions and Velocities between the
International Terrestrial Reference Frame of 2000 and North American Datum of 1983
(Soler & Snay, 2004). The same transformation is used in Canada.
- ITRF-NAD83 Transformation and Definition of NAD83(CSRS)
(Craymer et al., 1998; Revised 2001-12-12). Added ITRF2000 reference frame, now used by IGS
products (precise orbits, coordinate solutions, etc).
- Current U.S. National Geodetic Survey Coordinate
Transformation between ITRF2008 and NAD83/NSRS (same as NAD83/CSRS).
- Prior U.S.
National Geodetic Survey Coordiante Transformations between various ITRF's and NAD83/NSRS. Only
transformations since ITRF94 are the same as those used in Canada; i.e., those involving "NAD83 (CORS96).
- New ITRF97-NAD83(CSRS)
Transformation Adopted by Canada and U.S. US NGS Announcement. Note that some small but
insignificant differences exist due to round off errors in the transformation parameters adopted by
Canada and the U.S. Either set of paraemeters can be used to give mm resolution. The Canadian values
agree with the official IGS values to sub-mm resolution.
- Realization and Unification of NAD83 in Canada and the US via
the ITRF (Craymer et al., 1999). Also available in Adobe PDF file
- Plot of NAD83-ITRF Differences at CBN Points
Transformation parameters between ITRF reference frames.
- IERS Conventions 1996. Official definitions of celestial and terrestrial reference frames and adopted
models, constraints and standards.
- ITRF Reference Frame Transformations
- IGS Reference Frame Transformations
- A Compendium of Transformation Formulas Useful for GPS Work
(Soler, 1998; 239 KB). The original publication is available on LINK
- TRNOBS (Transform Observations)
Software to transform GHOST and GeoLab data files between NAD83(CSRS) and various ITRF
- HTDP (Horizontal Time Dependent Positioning)
Software from the US National Geodetic Survey that, among other
things, can be used to transform between NAD83 and ITRF.
- NTv2 (National Transformation Version 2)
The Canadian national standard to transform between NAD27 and NAD83 reference systems.
Canadian Active Control System
Map of CACS Network (with station descriptions and coordinates; password required)
- CACS solutions in CGRSC Data Archive
(password required; restricted to CGRSC members)
Provides historic and currently adopted NAD83 & ITRF coordinates, confidence regions, and GHOST,
GeoLab & SINEX data files to use as constraints in adjustments. Latest version is CACS v6.0,
based on the ITRF2008/IGS08 reference frame or a densification of it.
- Histograms of absolute 95% confidence ellipsoids
- JPL Coordinate time series for ACP/CORS/IGS
sites in/near Canada
Canadian Base Network
Map of CBN Network (with station descriptions and coordinates; password required)
- CBN solutions in CGRSC Data Archive
Provides historic and currently adopted NAD83 & ITRF coordinates, confidence regions, and GHOST, GeoLab
& SINEX data files to use as constraints in adjustments. Latest version is CBN v6.0, based on a
densification of the ITRF2008/IGS08 reference frame.
- Network Maps
- Histograms of absolute 95% confidence ellipsoids
- CBN v3.0 (no significant difference with v3.1)
- CBN v3.0 Versus NAD83(Adopted)
- CBN v2.0 Versus NAD83(Adopted)
Adjustments & Analysis
- GHOST Adjustment Software
- GSD GPS-Related Software & Guidelines
(from Geodetic Survey Division, Natural Resources Canada). Provides precise cm-level GPS
coordinates with respect to NAD83(CSRS) and the International Terrestrial Reference Frame
- GSD On-Line Geodetic Applications
-- Precise Point Positioning in both NAD83(CSRS) and ITRF
Download PPP Direct for Windows.
-- Transformation of geodetic coordinates between reference frames/epochs and conversion
of coordinates between coordinate systems (i.e., Cartesian, ellipsoidal and projections).
Replaces TRNOBS & GSRUG.
Download Windows software.
-- GPS Height Transformation Between ellipsoidal heights with respect to various reference frames
and orthometric heights with respect to various geoids in Canada
Download Windows software.
-- National Transformation v2 Between NAD27 and NAD83 in Canada
Download Windows software.
-- Direct and Inverse Geodetic Computations
- US NGS On-Line Geodetic Toolbox
(from Geodetic Survey Division, Natural Resources Canada). Software to transform coordinates between reference
frames & epochs and convert coordinates between different coordinate systems (i.e., Cartesian, ellipsoidal and
For a description of the software, see the text file
- Woods Hole Institution's NDSF Coordinate Conversion Utility
Converts between Latitude/Longitude, UTM and X/Y coordinate systems. Note that X/Y is defined by WHOI as a
topocentric Cartesian coordinate system at a user-defined location with X defined as the axis pointing towards
east and Y pointing towards north (i.e., a right-handed coordinate system). The usual geodetic convention is to
define the topocentric system as a left-handed Cartesian coordinate system (referred to as the local geodetic
system) with X pointing towards north, Y pointing towards east and Z pointing vertically up.
- SOPAC Online Date Converter
Converts between various date formats, including GPS week + day of week, year + day of year,
decimal year, modified Julian date, and year + month + day.
- Free GPS Data Processing Services
Automated Precise Positioning Service (APPS)
(from Jet Propulsion Laboratory, California Institute of Technology). A free GPS
data processing service using the GIPSY/OASIS-II (GOA-II)
PPP software and observation files in RINEX format. Estimates coordinates of a single site using
precise point positioning (precise orbits and clocks). Upload RINEX files via Web, FTP or email. Replaces
original AutoGIPSY service.
Scripps Coordinate Update Tool (SCOUT)
(from Scripps Orbit and Permanent Array Center). A free Web/FTP-based GPS data processing service
using the GAMIT software. Estimates coordinates of a single site using IGS stations as fiducial
points (you can specify which to use or have SCOUT select the nearest ones). To use, your RINEX
file must be accessable via anonymous FTP or you must upload it to their anonymous FTP server.
OnLine Positioning User Service (OPUS)
(from US National Geodetic Survey). A free Web-based GPS data processing service based on NGS's
PAGES software. Allows users to submit a GPS RINEX observation data file where the data will be
processed to determine a position by averaging baseline solutions to three nearest CORS stations.
AUSPOS -- Online GPS Processing Service
(from Geoscience Australia). A free Web-based GPS data processing service that allows users to
submit dual frequency, geodetic quality, GPS data in RINEX format observed in a 'static' mode
and receive rapid turn-around coordinates in ITRF or GDA. This service takes advantage of both
IGS products and the IGS GPS network using the Bernese
GNSS Software and works with data collected anywhere on Earth.
- Mike's Software Archive
A collection of some of some Fortran & MATLAB software
programs and libraries by Mike and others.
- GPS Toolbox
Discussion forum and archive of source code and algorithms discussed in the GPS Toolbox
column of the journal GPS Solutions.
- Guidelines for New and Existing Continuously Operating Reference Stations (CORS),
U.S. National Geodetic Survey, January 2013. See Chapter "Guidelines for Establishing and Operating a CORS",
Section "B. Monumentation".
- , December 2013.
See Chapter II, CORS/RTN Monument Construction Guidelines.
- National Continuously Operating Reference Station (National CORS) Site Monumentation
, National Geodetic Survey
Process Action Team 20, Final Report, U.S. National Geodetic Survey, December 20, 2000.
- Procedures For Setting A CORS Monument
U.S. National Geodetic Survey guidelines used by SuomiNet
(a slight variation of the above Appendix B).
These web pages are the sole responsibility of Michael Craymer. They are not
an official product of the Canadian Geodetic Survey or the Government of Canada.
Michael Craymer makes no guarantees, representations or warranties respecting
the contents of these Web pages, either expressed or implied, arising by law or
otherwise, including but not limited to, effectiveness, completeness, accuracy
and fitness for a particular purpose. Michael Craymer shall not be liable in
respect of any claim, demand or action, irrespective of the nature of the cause
of the claim, demand or action alleging any loss, injury or damages, direct or
indirect, which result from the use of these Web pages. Any mention of
commercial products does not imply an endorsement of those products.