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PCDWBA

Source: vignettes/pcdwba/index.Rmd
index.Rmd

Overview

Validated Experimental
Theory Implementation

The phase-compensated distorted-wave Born approximation (PCDWBA) calculates weak-fluid scattering from an elongated body while retaining the phase associated with its curved centerline.

Core idea

Use the local cross-sectional kernel of DWBA, but calculate position, local tilt, spacing, and two-way phase from the actual centerline rather than from a straight-axis reduction (Chu and Ye 1999).

Best for

  • Weakly contrasting elongated bodies with physically meaningful curvature
  • Uniformly bent cylinders or curved arbitrary profiles
  • Assessing the phase effect of curvature relative to a straight weak-scattering calculation

Supports

  • FLS scatterers converted to a DWBA-style radius and centerline profile
  • Curvature already present in the profile or supplied as a radius or radius-to-length ratio
  • Nodewise density and sound-speed contrast bookkeeping

Main assumptions

  • The same first-order weak-scattering regime as DWBA
  • Curvature changes position and phase but not the local scattering kernel
  • Single scattering from a fluid-like target
  • The centerline and local radius discretization resolve the target geometry

Validation status

  • Validated against source-level ZooScatR and Echopop PCDWBA workflows.
  • PCDWBA is currently marked experimental because the public package workflow is still being tightened even though the current source- level comparison cases are documented.

Family pages

  • Implementation: accepted profiles, curvature inputs, output, and comparisons
  • Theory: centerline geometry and phase-compensated sum

References

Chu, Dezhang, and Zhen Ye. 1999. “A Phase-Compensated Distorted Wave Born Approximation Representation of the Bistatic Scattering by Weakly Scattering Objects: Application to Zooplankton.” The Journal of the Acoustical Society of America 106 (4): 1732–43. https://doi.org/10.1121/1.428036.