SALAT_CONTRAST¶

SALAT_CONTRAST

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.

CALLING SEQUENCE:

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

INPUTS / OPTIONAL KEYWORDS

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`

OUTPUTS

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

EXAMPLE

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]]

Source code

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