An Automatic Event Detector at TFO
Abstract
The on-line operation of a Fisher detector has been evaluated at the Tonto Forest Observatory short-period seismic array. Using 31 seismometers and one fixed threshold, the 90 percent incremental detection threshold on the Kuril Islands beam, centered at delta = 70 degrees, is mb = 4.15 plus or minus .05; with an experimentally determined false alarm rate of 0.17 per day. This compares favorably with the capabilities of a human operator. Storms in the Kurils significantly affect the distribution of amplitudes of the Fisher detection trace; and we estimate that most of the false alarms observed at the operating threshold can be traced to the statistical bias introduced by this storm-generated energy. If the threshold were adjusted to maintain a constant false alarm rate, the maximum effect on the threshold magnitude would be 0.05 m sub b.
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 18, 1970
- Accession Number
- AD0881923
Entities
People
- R. R. Blandford
Organizations
- Teledyne Technologies