The Global Seismographic Network (GSN) produced specifications for a new generation of primary broadband seismic sensors. These instruments will replace the ~50 existing borehole sensors and the ~100 vault sensors in the network (plus spares). Starting in 2013, the GSN purchased, tested, and evaluated prototype sensors in order to begin replacement procurements starting in 2015.
The specifications provided below were assembled by the IRIS Instrumentation Committee, in collaboration with the USGS, and were used as part of a competitive bidding process. The specifications assume that sensors are traditional force feedback systems with three analog outputs which are digitized outside of the seismometer.
Noise model reference:
Berger, J., P. Davis, and G. Ekström (2004), Ambient Earth noise: A survey of the Global Seismographic Network, J. Geophys. Res., 109, B11307, doi:10.1029/2004JB003408