Short-Period Noise Envelope Statistics: A Basis for Envelope Detector Design
Abstract
This report focuses on the use of certain detection statistics, in particular the instantaneous amplitude or envelope, and the instantaneous power, in the design of a controlled false alarm rate detector. To achieve false alarm rate control, the detection statistic must be stationary, but need not be Gaussian. Parameters of a Gaussian process can be conveniently transformed into a stationary, normalized detection statistic. For an envelope detector the normalization consists of dividing the envelope by a long-term (1 to 2 minutes) estimate of the RMS noise level; the instantaneous power is normalized by dividing it by the long-term average power. The stationarity of the normalized envelope is demonstrated with one hour of uninterrupted, Korean Seismic Research Station single-site, short-period noise, by compiling distributions of the base- ten logarithm of the normalized envelope. The envelopes closely follow the Rayleigh distribution which is the theoretical distribution for envelopes of a Gaussian process. Retaining this model at the 5% significance level establishes adequate control of the false alarm rate.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 26, 1978
- Accession Number
- ADA066713
Entities
People
- Rudolf Unger
Organizations
- Texas Instruments