Airborne geophysical survey: Massachusetts Coop West (Includes part of Rowe ARMS '59)

Aeromagnetic data were collected along flight lines by instruments in an
aircraft that recorded magnetic-field values and locations. In the earlier
days of surveying, the only way to represent this data was to generate an
analog map with contour lines. This dataset is a representation of the
digitized contour lines either by following the lines or by choosing the
intersection of the contour and flight-line to create a value of the magnetic
field. The values presented are latitude, longitude, and map magnetic-field
values.

航空磁测数据（Aeromagnetic data）由航空器搭载的探测仪器沿飞行航线采集，同步记录磁场强度与位置坐标。在航空磁测的早期勘探阶段，此类数据唯一的可视化表达方式为绘制带等值线的模拟地图。本数据集为数字化等值线的成果载体，可通过沿等值线追踪或选取等值线与飞行航线的交点来获取对应磁场强度数值。本次发布的数据包含纬度、经度与航磁场强度值三类信息。