Accession Number:

AD0485031

Title:

THE CROSSWISE SUM METHOD FOR MAXIMUM-LIKELIHOOD FILTERING OF LASA SEISMOGRAMS.

Descriptive Note:

Scientific rept.,

Corporate Author:

TELEDYNE INDUSTRIES INC ALEXANDRIA VA EARTH SCIENCES DIV

Personal Author(s):

• Flinn, Edward A.
• Hartenberger, Royal A.
• McCowan, Douglas W.

Report Date:

1966-06-09

Pagination or Media Count:

11.0

Abstract:

The two earthquakes reported earlier, 10 November 2965 and 25 November 1965, were processed and analyzed using the crosswise sums method. With this method we first form 25 traces, each the phased sum of 21 prefiltered subarray traces, one from each subarray and then maximum-likelihood filter the set. The final outputs from the maximum-likelihood filter are 1.5 to 4 db down in signal-to-noise ratio from the phased sum of all of LASA. The signals are remarkably similar on these 25 crosswise sum traces so much that the symmetrical maximum-likelihood filter introduced no precursor. Author

Descriptors:

• *SEISMOGRAPHS
• STATISTICAL ANALYSIS
• PROBABILITY
• EARTHQUAKES
• SEISMIC WAVES
• DATA PROCESSING
• CORRELATION TECHNIQUES
• SIGNAL TO NOISE RATIO
• ELECTRONIC RECORDING SYSTEMS
• COMPUTERS
• ELECTROMAGNETIC WAVE FILTERS
• PHASED ARRAYS

Subject Categories:

• Seismology

Distribution Statement:

APPROVED FOR PUBLIC RELEASE