We have also found hundreds of pottery sherds, both Indian and Spanish, as well as food remains, beads, buttons, nails glassware and lead musket balls. Before digging, we often take advantage of information provided by remote sensing. A magnetometer survey records differences in the magnetic properties of the soil, which can tell us where metal is concentrated, and also where burned deposits are located. Aeriel image taken by Daed a lus Multispectral Scanner Low-level aerial imagery of the kind used by satellites can show us different properties of the soil beneath the surface. This one reveals different heat-holding properties of the earth, which can show where buried organic material is concentrated.
Trees are dark blue, and shell deposits and marsh mud are usually dark red.
Dr. Ryan Williams of Boston University conducting a magnetometer survey of the Fountain of Youth Park site before the 2001 excavations Ground-penetrating radar also helps us detect where underground disturbances are present. We later found another very large post containing a large amount of Spanish material.