SAI Support of the ONR Upper Crust Study.
Abstract
In the past few years, two substantial measurement programs (1,2) have been conducted for the purpose of measuring bottom loss in the low-frequency range below 1 kHz. Both programs have processed signals from explosive sources in various one-third octave bands and have used similar source-receiver geometries with both source and receiver within 300 to 800 feet of the ocean surface. For frequencies below 100 Hz, it is shown here that significant artifacts may be induced in the inferred bottom loss because of the combined choice of signal processing and source-receiver geometry. Furthermore, over the entire frequency range of interest, it is often likely that the inferred losses at low grazing-angle are contaminated by unsuspected intrustions of energy from the first convergence zone.
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 30, 1977
- Accession Number
- ADA056176
Entities
People
- J. S. Hanna