Envelope of Correlation Used with Deconvolution and Reconvolution to Remove the Direct Arrival in a Multipath Environment

• Main Author: Wilson, M. A.
• Other Authors: NAVAL OCEANOGRAPHIC AND ATMOSPHERIC RESEARCH LAB STENNIS SPACE CENTER MS
• Format: Text
• Language: English
• Published: 1990
• Subjects: Snow; Ice and Permafrost; Acoustic Detection and Detectors; *UNDERWATER SOUND SIGNALS; *MULTIPATH TRANSMISSION; *SONAR SOUND ANALYZERS; CORRELATION; PULSES; ACOUSTIC SIGNALS; SEPARATION; ACOUSTICS; ARRIVAL; AMPLITUDE; OCEAN ENVIRONMENTS; ENVELOPE(SPACE); CROSS CORRELATION; ARCTIC REGIONS; SOURCES; PACK ICE; COMPUTER PROGRAMS; PROPAGATION; DECONVOLUTION; PE62435N; WUDN496433; Arctic; Ice; permafrost
• Online Access: http://www.dtic.mil/docs/citations/ADA222309; http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=ADA222309

Separating overlapping direct and reflected arrivals, such as those propagated under pack ice from an acoustic source emitting frequency modulated sweep pulses, is a difficult problem in the analysis of high frequency arctic correlation data. To solve this problem, a correlation with the source pulse followed by a Hilbert transform is used to derive the envelope of correlation. This gives a reliable indication of the best cutoff time for separating multipath arrivals by a deconvolution followed by reconvolution. An added benefit from the software for the above cross correlation envelope is a plot of the relative amplitudes and arrival times for each propagation path. (jhd)