Requirements, needs, wants:

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Requirements, needs, wants

• There is an impending CRISIS in the low
  frequency seismological research community now
  that the STS1 seismometer is no longer
  manufactured there is a danger of losing the
  capability to capture unique information about
  the Earth. (What makes the STS-1 unique?
  Instrument noise at frequencies below 10-2 Hz
• We also want to take advantage of opportunities
  to go beyond what we can now record to resolve
  even lower amplitude signals.

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Requirements, needs, wants

• We can resolve most signals of seismological
  interest for frequencies above about 1 Hz at most
  sites with existing, readily available
  seismometers. (With the possible exception of NE
  detection.)
• For frequencies below about 0.05 Hz, we need to
  seismometers capable of resolving signals perhaps
  at or below the currently observed noise
  background.

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Requirements, needs, wants

• wish to resolve true ground noise throughout
  band (note LNM (??) not well known at frequencies
  above a few Hz).
• want to record 6 components of motion (rotation
  as well as translation)(see Langston eg) (near
  field)

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Requirements, needs, wants _at_ observatories
(lt10-4 to 10-2 Hz)

• There are 200?? observatory class stations now
  extant
• less sensitive to cost
• very sensitive to noise floor
• better recording of horizontal motion esp
  compensating for tilt -( better installation
  techniques new types of instrumentation)
• need both vault and borehole instruments for
  existing observatories.

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Requirements, needs, wants _at_ observatories
(lt10-4 to 10-2 Hz) (cont)

• need borehole instruments for ocean floor and
  islands
• need to better understand noise in this band

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Requirements, needs, wants Intermediate band
(10-2 -20Hz)

• includes both observatory and portable sensors
  (separate)
• need lower noise performance above 1 Hz
• prefer compact packaging for ease of deployment
  for portable versions
• need to track metadata (location, orientation)
• more price sensitive
• Total of XX units over yy years

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Requirements, needs, wants High Frequency (EQ
Engineering)

• place in high cultural noise background
• Data acquisition system included
• need greater sensitivity than now exists
• very price sensitive (need lt1K/channel)
• low gain velocity sensor desirable
• continuous recording

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Requirements, needs, wants Above 20 Hz

• cheap, stable, rugged, watertight, quiet(er)
• more sensitive than MEMs now offers (at least 10
  dB lower - what resolution ?)
• want to use in arrays and still be cost
  effective xxx units over yy years