A numerical procedure for recovering scattering coefficients from measurements with wide-beam antennas

A numerical procedure for estimating true scattering coefficients, σ⁰, from measurements made using wide-beam antennas is discussed. The use of wide-beam antennas results in an inaccurate estimate of σ⁰. To reduce this error, the authors propose a correction procedure that estimates the error resulting from the use of narrow-beam approximation and utilizes the error to obtain a more accurate estimate of σ⁰. An exponential model is assumed to take into account the variation of σ⁰ with incidence angles, and the model parameters are estimated from measured data. Based on the model and knowledge of the antenna pattern, the procedure calculates the error due to the narrow-beam approximation. The procedure is shown to provide a significant improvement in the estimation of σ⁰ obtained in wide-beam antennas. The proposed procedure is also shown to be insensitive to the assumed σ⁰ model