Airborne geophysical survey: Massachusetts Coop '61 (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.

航空磁测数据由航空器搭载的仪器沿飞行航线采集，同步记录磁场数值与位置信息。在早期的航磁测量工作中，此类数据唯一的可视化表达方式为绘制带有等值线的模拟地图。本数据集为数字化等值线的成果形式，其数据生成方式包括沿等值线逐段追踪采样，或选取等值线与飞行航线的交点以获取对应磁场数值。本次发布的数据包含纬度、经度与测点磁场强度三项参数。