Airborne geophysical surveys

Survey name Type Altitude Spacing Flight line distance
HoquiamM/R-D121.9 m 9.60 km2,282 km
Longview NorthM-D304.8 m above ground0.80 km13,888 km
CentraliaM-D200 m above ground0.40 km23,501 km
Southwest Washington '51M-Dz304.8 m above ground0.80 km4,090 km
S.W. Washington-NW OregonM-D914.4 m (barometer)3.20 km2,245 km
Columbia RiverM-D228.6 m above ground0.40 km4,200 km