Hayashi, Y., 1983: Modified methods of estimating space-time spectra from polar-orbiting satellite data Part I: The frequency transform method. Journal of the Meteorological Society of Japan, 61 (2), 254-261.

Abstract: A simplification is made of the nonorthogonal Fourier transform method (Salby, 1982) for estimating space-time spectra from uneven twice-daily data sampled by a polar-orbiting satellite. The modified method transforms frequency only by the use of the Galilean transformation, while Salby's method transforms both frequency and wavenumber. Space-time spectra are obtained from the time-Fourier transform with respect to the Doppler-shifted frequency as viewed from the satellite. The wavenumber-frequency aliasing characteristics are examined and the computer code is exemplified.