SUMMARY OF DART II PERFORMANCE CHARACTERISTICS/SPECIFICATIONS
Mandatory Characteristic
Measurement sensitivity
Sampling interval, internal record
Sampling interval, event reports
Sampling interval, tidal reports
Two-way end-to-end communications
Tsunami data report trigger
Data flow, BPR to TWC
Specification
Less than 1 millimeter in 6000 meters; 2 * 10-7
15 seconds
15 and 60 seconds
15 minutes
On demand, tsunami warning center (TWC) trigger
Automatically by tsunami detection algorithm
Less than 3 minutes after triggered event
Desired Characteristic
Reliability and data return ratio
Maximum deployment depth
Minimum deployment duration
Operating Conditions
Theoretical Battery Life, buoy
Theoretical Battery Life, tsunameter
Maximum status report interval
Specification
Greater than 80%
6000 meters
1 year
Beaufort 9
Greater than 2 years
Greater than 4 years
Less than 6 hours
Iridium uses a Motorola 9522 L-band trans- ceiver from NAL Research at 2400 baud.
GPS is a Leadtek model 9546 receiver
Buoy:
--- Fiberglass over foam.
--- Computer is 32-bit, 3.3 volt Motorola 68332
--- System electronics use 2560 watt-hour D-cell battery pack.
Mooring is 19 mm 8-strandplaited nylon line with rated breaking strength of 7100 kg.
Acoustic modems on tsunameter and buoy:
--- Benthos ATM-880 Telesonar with AT-421LF directional transducer.
--- Powered by 1800 watt-hour batteries.
Tsunameter:
--- Pressure sensor is a 0-10000 psi model 410K Digiquartz Paroscientific unit.
--- Tilt sensor is Geometrics 900-45 to determine orientation.
--- Uses Alkaline D-cell battery with 1560 watt-hour capacity.
--- Uses same computer as buoy.