Next Generation Robust Low Noise Seismometer for Nuclear Monitoring

Effective global monitoring of nuclear explosions calls for a worldwide network of seismic stations. This project is aimed at the implementation of the next generation, very low noise, broadband, wide dynamic range, very robust force-balanced digital seismometer for seismic monitoring of nuclear explosions. The seismometer will incorporate a high-resolution, low noise, low-power 24-bit digitizer that will provide digital outputs with velocity-flat (and optional acceleration-flat and combined velocity/acceleration-flat) response. The noise level will be at least 10dB below the USGS New Low Earth Noise Model, with a dynamic range no less than 136dB over the 0.02 to 16Hz frequency band. The new instruments will stay fully functional at installation tilts of at least ±10°. In addition to the digitizer, each seismometer also will contain an ultra-low power microcontroller that will monitor gain and transfer function stability; provide for prompt, accurate temperature compensation over the full operating temperature range; and perform on demand or periodical seismometer calibration. A few proof-of-concept prototype seismometers will be built in Phase I, with full pre-production units built in Phase II. Commercial Applications and other Benefits as described by the awardee: The new seismometer should serve vital national interests by greatly facilitating global compliance with nuclear non-proliferation and detecting possible violations of the Comprehensive Nuclear Test Ban Treaty. The new seismometers also should be very competitive in various niches of the worldwide seismic market, due to their low noise over broad passband and exceptional ruggedness. The new instruments would be easily and quickly deployable in field and stationary vault environments, and would offer low cost of ownership since they require no maintenance.