Grid: Bethel/Russian Mission mag grid

Author: Jeff Phillips, USGS, Denver

Datum: DGRF removed

Data format: Ascii format, XYZ records
             Longitude (degrees), Latitude (degrees), Total Field (nT)
             written with FORTRAN format: (f10.5,x,f10.5,x,f8.1)

Notes:

This grid has been draped to 1000' above terrain (not reduced to the pole).
The XYZ records are extracted from the original 0.5 km projected grid 
(Transverse Mercator, baslat=0, cm=-160.5) and unprojected to
lat/lon coordinates.

This grid contains data from a field survey by Jeff Phillips during
work on the AMRAP project for the Bethel Quad (year?) as well as
data from later State of Alaska contracted surveys.