Truncation-Error Reduction in 2D Cylindrical/Spherical Near-Field Scanning

We introduce a near-field to far-field transformation for two-dimensional cylindrical/spherical scanning that significantly reduces angular-truncation errors. After examining the limitations of the traditional multipole-based expansion of truncated scan data, we consider an alternative expansion based on Slepian functions and show how far-field values can be extracted from the resulting expansion coefficients. We compare the performance and computational cost of the new transformation with those of the traditional one.