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Station Report

Geoid velocity added

To correct for the vertical drift between reference frames, the velocity of the geoid height (VN) is now calculated and incorporated into the calculation of the orthometric height. View documentation to learn more.

WARNING: The use of small antennas on larger diameter concrete pillar CBN monuments can result in vertical position biases of up to 3 cm when using the GPS L2 signal due to potential signal multipath reflections from the top of the pillars. It is recommended to mount such antennas as close as possible to the top of the pillar to reduce multipath effects (e.g., 5 cm or less from the antenna reference point). Larger diameter antennas that cover most of the tops of these pillars are not significantly affected by this kind of multipath.

Site Identification

Name Province NTS map sheet Unique Number Provincial Identifier Network
LON1 LONDON PIER1 Ontario 040I14 813041 CBN

Station Coordinates

Unless otherwise noted, all displayed uncertainties are computed at the 68% (1-sigma) confidence level.

Changing these fields will auto-update the station coordinate information below.

The velocities are interpolated from the national Velocity Grid version 7.0.

h (metres)
Vφ (mm/y)
Vλ (mm/y)
Vh (mm/y)
X (metres)
Y (metres)
Z (metres)
Vx (mm/y)
Vy (mm/y)
Vz (mm/y)
Easting (metres)
Northing (metres)
h (metres)
N (metres)
H (metres)
Published date Project ID 2023-09-05       M18-020
VN (mm/year)
VH (mm/year)
Equipot. of geoid model (W0, m2s-2)

Vertical Data (levelling)

Vertical Datum Elevation (m) Order Gravity (mGal) Published Project ID
CGVD2013 (2010.0) 271.504 1st 980327.06 2013 H13ML1311
CGVD28 271.943 1st 980426.62 1999 N27U99

The CGVD2013 height reported in the Vertical Data table is approximate because it is calculated from historical levelling data and not from the combination of GNSS and a geoid model.

Vertical Datum Separation

Datum 1 − Datum 2 Elevation 1 (m) Elevation 2 (m) Elevation Difference (m) Epoch

Station Marker

Marker Type Inspected in Established by Status Comments
Self centering plate 2015 Canadian geodetic survey - nrcan Good


Accessible by passenger car or light truck and a walk of less than 50 m.

London london calibration baseline pier n0. 1 (cbn pillar), concrete pillar with steel top plate on southeast side of highway no. 401, 2.8 km southwest of highway no. 402 overpass, 3.8 km northeast of talbot road overpass, 111 m southwest of centre of scotland drive overpass, 36.7 m from centre line of eastbound lane of highway no. 401, 17.8 m northwest of centre of wonderland road (sideroad running parallel to highway no. 401), opposite point on wonderland road 8.8 m northeast of "intersection ahead" sign for eastbound traffic, 2.8 m northwest of fence line, about 4 m above level of highway no. 401. Elevation taken on top at centre of main circular plate anchored on top of pillar.

Use of Canadian Geodetic Survey products and data is subject to the Open Government Licence - Canada

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