CTAM Projection:

The CTAM dataset has been converted from a geographic coordinate system
to a projected Lambert Conformal Conic system.  The following are the
specifics for the Lambert Conformal Conic system:

•	Projection:  Lambert Conformal Conic
•	Standard Parallels:  -82.850000, -83.650000
•	Longitude of Central Meridian:  154.500000
•	Latitude of Projection Origin:  -83.250000
•	False Easting: 300000 meters
•	False Northing:  175000 meters
•	Datum:  WGS84
•	Local Datum Transform:  [WGS84] World

/grids
contains final magnetic grids in Geosoft Oasis Montaj binary format:
ctam_usgs.grd - USGS final magnetic grid
ctam_bgr.grd - BGR final magnetic grid

/database
contains final database in both Geosoft .gdb and .xyz format

Database channels:

Longitude - Longitude WGS84
Latitude - Latitude WGS84
x - Lambert Conformal Conic
y - Lambert Conformal Conic
ellipsoid_elv - height of WGS84 ellipsoid
Date - Date
UTC - Universal Time Coordinated
mag_field - Total magnetic field
mag_field_lp - despiked total magnetic field with low-pass filter
	applied
base_station_raw - raw base station values
base_station_sm - base station values smoothed by removing dropouts and
	linearly interpolating with a spline filter
diurnal_raw - mag_field_lp diurnally corrected with raw base station
	data (60340-base_station+mag_field_lp, where 60340 represents an average
	base station value)
diurnal_sm - Mag_field_lp diurnally corrected with smoothed base station
	data (60340-base_station+mag_field_lp, where 60340 represents an average
	base station value)
IGRF - International Geomagnetic Reference Field for 10th January 2004 -
	Model year 2000
mag_final_sm - final residual mag with smoothed base station and IGRF
	removed (diurnal_sm-IGRF+60340, where 60340 represents an average base
	station value)
residual - Anomalous magnetic field (mag_final_sm-60340, where 60340
	represents an average base station value)
leveled - Anomalous magnetic field tie-line leveled using standard
	defaults with Geosoft software and microleveled using an amplitude of 10
	nT as cutoff