Specifications include, but are not limited to: The Broadband Seismometer (hereafter ‘seismometer’) shall produce 3 orthogonal outputs representing ground motion. 1.2. The seismometer shall have an analog output, (e.g. ±20 V), differential, one output for each channel, and have a flat response to earth velocity. 1.3. The seismometer shall have a sensitivity at differential output of no less than 1,200 V/m/s. 1.4. The seismometer and its associated leveling system shall be free of parasitic resonances below 100 Hz 1.5. The seismometer and associated leveling system shall make broadband measurements of ground velocity at instrument noise levels that are no more than the USGS NLNM within a frequency band extending over the range from ≤8.3 mHz (120 s) to 10 Hz (0.1 s). 1.6. The seismometer shall support a dynamic range of ≥ 150 dB in the frequency band 8.33 mHz to 10 Hz. 1.7. The seismometer shall have a frequency pass band with a flat velocity response within 3 dB from the -3 dB points of 2.8 mHz (360 s) to ≥ 20 Hz (0.02 s). 1.8. The seismometer shall have a clip level that is greater than the output voltage. 1.9. The seismometer shall measure and deliver mass position outputs for all 3 components. 1.10. The Broadband Seismometer shall be linear from the noise floor to 100 dB above the noise floor. 1.11. The Broadband Seismometer shall have capability of calibration via remotely injected signals while deployed. 1.12. The seismometer shall provide a means of leveling axes when the OBS package is deployed at an angle of up to 20 degrees from horizontal. 1.13. The seismometer masses shall be capable of being auto-leveled and auto-centered or re-leveled upon application of a remote mass-centering command. 1.14. The seismometer shall have the capability to remotely command the sensor to lock or unlock masses, if mass-locking is necessary. 1.15. The seismometer shall be capable of reporting case tilt with respect to the vertical. 1.16. The polarities of the seismometer’s output signals shall be positive for earth motion UP, NORTH, EAST (Z,N,E). 1.17. The seismometer’s magnetic susceptibility shall be less than 0.003 m/s^2 per T. 1.18. The temperature range over which no mass centering is required shall be no less than ±2°C
