Accession Number:

ADP006379

Title:

Parabolic Equation Modelling of Backscatter from the Rough Sea Surface,

Descriptive Note:

Corporate Author:

RUTHERFORD AND APPLETON LABS CHILTON (UNITED KINGDOM)

Personal Author(s):

Report Date:

1991-09-01

Pagination or Media Count:

10.0

Abstract:

This paper presents a physically based numerical method for calculating sea clutter at low grazing angles for microwave frequencies. Sea clutter is modelled as a two-scale phenomenon at low grazing angles, the backscattered energy is generated by ripples on the sea surface. A first order perturbation method gives the backscatter from a small patch of surface, as a function of the angle of incidence and of the magnitude of the incident field. Returns from a clutter cell are obtained by incoherent summation of these echoes. Shadowing and tilting effects due to the larger scale components of the sea surface are modelled using a finite difference implementation of the parabolic equation method, which also deals with atmospheric refraction effects. Realizations of the sea surface with the desired spectral characteristics are generated with a Monte Carlo method. Results are presented at S band and X-band for a variety of propagation conditions.

Subject Categories:

  • Active and Passive Radar Detection and Equipment
  • Physical and Dynamic Oceanography

Distribution Statement:

APPROVED FOR PUBLIC RELEASE