The active MASW needs a longitudinal receiver array with vertical oriented receivers and a constant spacing. A vertical impact source is required for excitation.

Receivers can be geophones with low natural frequencies (e.g. 4.5 Hz) or accelerometers. If the receivers are assembled to a landstreamer huge amounts of shot points can be measured in a short time. Small projects can be tackled with planted sensors. At least 12 receivers are necessary.

Accelerated drop weight mounted at vehicle

MASW Test using a landstreamer