Details: The
Cranbrook map features an airborne aeromagnetic survey, conducted in 1993
and 1994. The files are also available for download
in georeferenced PNG format.
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Cranbrook Geophysics Map
Survey Background
CRANBROOK GEOPHYSICAL SURVEY
Open File GSC 2784
1995 Aeromagnetic Total Field Map, British Columbia
(Parts of NTS 82N/NW)
The aeromagnetic survey was carried out by Geonex
Aerodat Inc. using a Cessna 310 aircraft. A 0.005 nT sensitivity split-beam cesium vapour magnetometer was mounted in the
tail boom of the survey aircraft.
The survey operations were carried out
from June 3 to 26, 1993, October 8, 1993 to March 5, 1994 and July 7 to 12,
1994. The survey was flown at a mean terrain clearance of 305 metres. Average
traverse line spacing was 800 metres and the control lines were flown at a 5000 metre
spacing. Flight path was recovered using a differential Global Positioning
System and a Doppler Navigation System coupled with a vertically mounted
video camera.
After editing the survey data, the
intersections of traverse and control lines were established and the
differences in the magnetic values were computer analyzed and manually
checked to obtain the level network. The levelled total field values were
interpolated to a 200 metre grid. The International Geomagnetic Reference Field
has not been removed. The data were processed and plotted by Geonex Aerodat
Inc.
Copies of this map may be obtained from
the Geological Survey of Canada, 601 Booth Street, Ottawa, Ontario, K1A 0E8
and 3303-33rd Street N.W.. Calgary, Alberta, T2L 2A7. It is also
available online at the
MIRAGE and at the
Geoscience Data Repository. The geophysical data used to compile
this map are available in digital form from the Geophysical Data Centre,
Geological Survey of Canada, 1 Observatory Crescent, Ottawa, Ontario. K1A
0Y3.
Analogue and digital products
include data for magnetic parameters in two projections:
