Line - Line number in local coordinates
Station - Station number in local coordinates
UTME_NAD83_Z7N - UTM zone 7N easting coordinate in the NAD83 datum 
UTMN_NAD83_Z7N - UTM zone 7N northing coordinate in the NAD83 datum 
X1 - X20 - Twenty x channels (nV/m^2/A)
Y1 - Y20 - Twenty y channels (nV/m^2/A)
Z1 - Z20 - Twenty z channels (nV/m^2/A)
ZN1 - ZN20 - Twenty z channels normalized to the primary field (nV/m^2/A)
Gain - Gain setting 
Primary_N_Gain - Primary field (nV/m^2/A)