Advanced Propagation Model (APM) Ver. 1.3.1 Computer Software Configuration Item (CSCI) Documents

Barrios, Amalia E.; Patterson, W. L.; Sprague, Richard

doi:10.21236/ada408521

Cited by 46 publications

(19 citation statements)

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“…Formulae (1)- (10) combined with the Advanced Propagation Model (APM) routines [24], which are based on a hybrid ray optics/PE method, are used to compute the PF and PL for microwave propagation over rough sea in the presence of evaporation duct. The parameters of the problem (grazing angles, low altitudes) require mainly the use of the PE-based part of the APM for which the electromagnetic field calculations are based on the two-dimensional (2D) narrow-angle forward-scatter scalar PE [14] given by (11):…”

Section: Theoretical Backgroundsmentioning

confidence: 99%

“…The APM [24] is based on a split-step Fourier-transform (SSF) solution of the PE [13,14]. The SSF allows larger step sizes and shorter computational time in comparison to Finite Difference [14] and Finite Element [17] based numerical solutions of (11), [14].…”

Section: Theoretical Backgroundsmentioning

confidence: 99%

“…A wide-angle propagator is also included that allows treating propagation problems requiring larger propagation angles with respect to the horizon; see [16] and the discussion in [15] about the introduction of the wide-angle propagator. The local grazing angles ϕ are determined by a combination of spectral estimation and geometric optics methods [15,24]. The surface impedance characteristics are calculated as a function of frequency using permittivity and conductivity graphs given in [28].…”

Section: Theoretical Backgroundsmentioning

confidence: 99%

“…The surface impedance characteristics are calculated as a function of frequency using permittivity and conductivity graphs given in [28]. In order to insure the radiation condition and prevent spurious reflections from the upper computational window boundary, an attenuation function (Tukey "window") is used to "filter" the field strength in the highest 1/4 of the calculation domain [16,24]. The initial field U (0, z) required to start the calculation procedure is obtained using the relation between the far-field antenna pattern F (p) and the aperture field distribution A(z) which form a Fourier transform pair [14,16].…”

Section: Theoretical Backgroundsmentioning

confidence: 99%

“…The proposed work combines the phase-corrected Ament RRF obtained in [23] and the PE method as implemented in the Advanced Propagation Model (APM) [14,24] to compute the propagation factor (PF) for microwave propagation over the ocean under evaporation duct conditions. A comparison is made between the PFs calculated for phase-corrected Ament, non-phase-corrected Ament and Miller-Brown rough surface reflection coefficients.…”

Section: Introductionmentioning

confidence: 99%

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Propagation Factor and Path Loss Simulation Results for Two Rough Surface Reflection Coefficients Applied to the Microwave Ducting Propagation Over the Sea

Sirkova

2011

PIER M

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Abstract-The performance assessment of maritime microwave communications and radar systems requires accounting simultaneously for the non-homogeneous propagation medium over the sea and the rough sea surface scattering. The tropospheric ducting, specific for over water propagation, is one of the most difficult to treat propagation mechanisms. The proposed work combines a recently published in the literature phase correction, responsible for the shadowing effects, to the Ament rough surface reflection coefficient and the Parabolic Equation method (as implemented in the Advanced Propagation Model) to simulate the microwave propagation over the sea under evaporation duct conditions. Propagation factor and path loss results calculated for phase-corrected Ament, non-phase-corrected Ament and the other widely used, Miller-Brown, rough surface reflection coefficient are compared and discussed. The main effects from the accounting of the shadowing result in the shift of the interference minima and maxima of the propagation factor, changes in the path loss pattern and destruction of the trapping property of the duct.

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Section: Theoretical Backgroundsmentioning

confidence: 99%