Passive Seismic

Description

The purpose of the passive seismograph experiment (PSE) (S-031) was to monitor lunar seismic activity and to detect meteoroid impacts and free oscillations of the moon. Lunar crustal tidal deformations could also be detected. The experiment consisted of two seismic assemblies -- (1) a long-period (LP) seismometer (triaxial orthogonal) with a seismic frequency response of 0.004 to 3 Hz (80 db dynamic range) and (2) a short-period (SP) seismometer (uniaxial, vertical motion) with a seismic frequency response of 0.05 to 20 Hz (80 db dynamic range). The minimum detectable signals of the PSE were 10 microns for the SP and all LP seismic signals, 0.4 arc-sec for the LP horizontal tidal output signal, and 320 microgals for the LP vertical tidal output signal. The PSE electronics package, located in the central station, was connected by cable to the seismometers.