SC2MAPFFT

Fourier Transform 2D maps

Description:

This routine performs the forward or inverse FFT of a 2D map. The FFT of the data are stored in a 3-dimensional array with dimensions xfrequency, yfrequency, component (where component is a dimension of length 2 holding the real and imaginary parts, or ampliude and phase if in polar form). The inverse flag is used to transform back to the spatial domain from the frequency domain. If the data are already in the requested domain, the ouput file is simply a copy of the input file.

Parameters:

AZAVPSPEC = _LOGICAL (Read)
If true, calculate the azimuthally-averaged angular power power spectrum. POLAR and POWER are set implicitly. [FALSE]
IN = NDF (Read)
Input files to be transformed.
INVERSE = _LOGICAL (Read)
Perform inverse transform. [FALSE]
MSG_FILTER = _CHAR (Read)
Control the verbosity of the application. Values can be NONE (no messages), QUIET (minimal messages), NORMAL, VERBOSE, DEBUG or ALL. [NORMAL]
OUT = NDF (Write)
Output transformed files.
POLAR = _LOGICAL (Update)
Use polar representation (amplitude, argument) of FFT. [FALSE]
POWER = _LOGICAL (Update)
Use polar representation of FFT with squared amplitudes divided by the frequency bin spacing (gives a power spectral density, PSD). [FALSE]
ZEROBAD = _LOGICAL (Read)
Zero any bad values in the data before taking FFT. [TRUE]

Notes:

Transforming data loses the VARIANCE and QUALITY components.

Related Applications

SMURF: SC2FFT