3.    Digital World Wide Standardized Seismograph Network - DWWSSN:  [ DW ]

DATES OF OPERATION:  03 Nov 1981 to 05 Oct 1987  

SEISMOMETER TYPE: 
Benioff Short Period vertical seismometer, Geotech Model 1051
for SHZ data. Sprengnether long period seismometers (one vertical Model 
S-5007-V previously Model 201 and two horizontal Model S-5007-H previously 
Model 100) which are used for both long period and mid period data.

DIGITAL FORMAT:  
16 bit integer data words for all components.  Range: +32767 to -32768 counts.

EVENT DETECTOR ALGORITHIM: 
The event detector used for the SHZ channel was developed at the ASL and is not
documented.  The mid-period channels are detected on a straight forward 
amplitude basis.

• Channel Data
• Amplitude Response to Ground Velocity
• Seismic Noise Study graph information

• Seismic Noise Level - Annual
• Seismic Noise Level - Seasonal/Diurnal

COMMENTS:  A description of the Digital World Wide Standardized Seismograph 
Network (DWWSSN) can be found in Peterson et al (1982).