Accession Number:

ADA101676

Title:

Design Criteria for a Deep Towed Source and Multi-Channel Array.

Descriptive Note:

Corporate Author:

CHUTE-STOFFA INC NYACK NY

Personal Author(s):

Report Date:

1979-07-16

Pagination or Media Count:

60.0

Abstract:

The accuracy of sedimentary interval velocities derived from a towed hydrophone array can be predicted in the ideal case of horizontal interfaces and an idealized source pulse. The parameters of the prediction model are the two-way normal-incidence travel time and RMS velocity to the horizon of interest, array length, and source pulse width. First, the range of RMS velocities likely to be encountered in the upper 500 m of sediments is determined. Second, the error in these RMS velocity measurements is calculated as a function of array length, height above the sea floor and pulse width. Third, the RMS velocity error is converted to interval velocity error as a function of layer thickness and velocity, pulse width, and array length and height. It should be emphasized that these errors do not include any additional errors generated by the hyperbolic travel-time assumption and do not include the degradation encountered for dipping layers. In addition, our discussion refers to the analysis of one Common Shot Point or Common Depth Point Gather. Considerable improvement in an average interval velocity determination can be obtained by the analysis of several nearby CSPs or CDPs. This improvement will depend on lateral continuity for the horizons of interest.

Subject Categories:

  • Physical and Dynamic Oceanography
  • Acoustic Detection and Detectors
  • Acoustics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE