Remote Sensing

Today Kendal McDonald will finish a magnetometer survey of the World War I Spruce Mill site east of the reconstructed fort. On Wednesday, Kendal conducted a workshop with the students on the main parade ground and then collected data from a 20 X 20 m square on the suspected site of the original US Army flag pole. Kendal's magnetometer is a Geometrics G-858 dual sensor cesium magnetometer configured as a gradiometer. She records the magnetic signature of the sediments she walks over and contrasts it with the magnetic "noise" of overhead power lines, solar radiation, and other intrusive magnetic disturbance. The resulting magnetic gradient between the two is used to look for changes in the sediment magnetic signature tied to metal objects, old pits, hearths, and foundations. 

Besides the flag pole location, we hope to find foundations, rail lines and other remains of the spruce mill. The mill cut spruce logged from the coast range into pieces suitable for making aircraft during the Great War.