init_source

lsst.meas.extensions.scarlet.init_source(frame, peak, observation, bbox, symmetric=False, monotonic=True, thresh=5, components=1)

Initialize a Source

The user can specify the number of desired components for the modeled source. If scarlet cannot initialize a model with the desired number of components it continues to attempt initialization of one fewer component until it finds a model that can be initialized.

It is possible that scarlet will be unable to initialize a source with the desired number of components, for example a two component source might have degenerate components, a single component source might not have enough signal in the joint coadd (all bands combined together into single signal-to-noise weighted image for initialization) to initialize, and a true spurious detection will not have enough signal to initialize as a point source. If all of the models fail, including a PointSource model, then this source is skipped.

Parameters:

frame : LsstFrame

The model frame for the scene

peak : PeakRecord

Record for a peak in the parent PeakCatalog

observation : LsstObservation

The images, psfs, etc, of the observed data.

bbox : lsst.geom.Box2I

The bounding box of the parent footprint.

symmetric : bool

Whether or not the object is symmetric

monotonic : bool

Whether or not the object has flux monotonically decreasing from its center

thresh : float

Fraction of the background to use as a threshold for each pixel in the initialization

components : int

The number of components for the source. If components=0 then a PointSource model is used.