Investigate the Hartley Transform as a replacement of the Fourier Transform for radio astronomy imaging. The Hartley Transform is already in use in the package DIFMAP in VLBI, but has not been used in standard interferometric reduction packages.
Paper - 1 - Fast Hartley Transform Algorithm
Paper - 2 - The Fast Hartley Transform as an Alternative to FFT
Paper - 3- Interferometric Mapping using the Hartley Transform