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Compute and plot "mean intensity" and "rms intensity contrast" of a cube and indicate bad/good frames based on a given threshold. Gaps (due to ALMA calibration routines) are marked with Red dashed lines.


IDL> bestframe = salat_contrast(cube, limit=limit, badframes=badframes, goodframes=goodframes)

Option Description Status
CUBE The ALMA FITS cube in [x,y,t] format. required
SHOW_BEST If set, location of the best frame (i.e., that with the largest rms contrast) is indicated on the plot. optional
TITLE It should be set if the cube is a fits file. optional
SIDE Number of pixels to be excluded from sides of the field of view prior to calculations of the mean intensity and rms contrast. optional
Parameter Description
BESTFRAME Index of the best frame (i.e., that with the largest rms contrast).
TIME_INDEX Name of a variable for the frame indices sorted from the highest to lowest rms-intensity-contrast image

Reading the data, header, time, and beam information from a SALSA data cube:

IDL> cube = './solaralma.b3.fba.20161222_141931-150707.2016.1.00423.S.level4.k.fits'
IDL> bestframe = salat_contrast(cube, /show_best, time_index=time_index)
 -- Variation of mean brightness (imean): -0.44 %
 -- Variation of rms intensity contrast (rmsCont): -11.07 %
IDL> im = readfits(cube)
IDL> best_ten_frames_cube = im[*,*,time_index[0:9]]

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