tweak_flt

grizli.prep.tweak_flt(files=[], max_dist=0.4, threshold=3, min_flux_radius=0.5, max_flux_radius=5, min_nexp=2, max_pixels=1.0, max_nmask=0, verbose=True, tristars_kwargs={'auto_keep': 3, 'auto_limit': 3, 'auto_transform': None, 'ba_max': 0.9, 'ignore_rot': True, 'ignore_scale': True, 'maxKeep': 10, 'size_limit': [5, 1800]}, ref_exp=0, use_sewpy=False, master_radec=None, make_figures=False)[source]

Refine shifts of FLT files

Parameters
fileslist

List of flt filenames

max_distfloat

Maximum shift distance to allow

thresholdfloat

Source detection threshold for sep.extract

min_flux_radius, max_flux_radiusfloat

Range of FLUX_RADIUS values to allow

min_nexpint

Minimum number of exposures contributing to a source

max_pixelsfloat

Maximum pixel offset relative to median to allow for sources in each exposure catalog

max_nmaskfloat

Maximum value of MASK_APER_0 to allow, i.e., to remove sources with central saturated pixels

verbosebool

Status messages

tristars_kwargsdict

Keyword arguments for tristars.match.match_catalog_tri

ref_expint

Index of the exposure to use as the reference for the tweak shifts. If < 0, then use the exposure with the longest integration time.

use_sewpybool

Use sewpy for source detection (deprecated)

master_radecstr

Filename of a list of reference (ra,dec) positions to match. If not provided, then align to the first exposure of the list

make_figuresint, bool

If True, then make a diagnostic figure with the shift residuals. If 2, then make individual tristars match figures as well.

Returns
ref_wcsWCS

Reference WCS (WCS of the first file in files)

shift_dictdict

Shift dictionary with keys from files and values like [xshift, yshift, rot, scale, N, rms]. Note that only shifts are fit, so rot = 0. and scale = 1.. N is the number of sources used for the fit.

catslist

List of tuples of the catalog and WCS derived from each exposure

figNone, Figure

Returns the figure object if make_figures tests True