Image calibration

The process of transforming a post-ISR image into a science-ready visit_image.

The Monster catalog

A whole-sky standard star catalog built specifically for LSST.

• The Monster reference catalog

Photometric calibration

Photometric calibrations relate the counts (electrons) measured by the camera to the incident flux from a source at Earth before it enters the atmosphere.

• Photometric calibration

Astrometric calibration

Astrometric calibrations define the World Coordinate System (WCS) of an image, the relation between pixel coordinates and sky coordinates (Right Ascension and Declination).

• Astrometric calibration

Point spread function modeling

Characterizing how the optical system and atmosphere “blur” a point source into a two-dimensional shape on the detector.

• Point spread function (PSF) modeling

Background subtraction

Removing the sky background flux from the image.

• Background subtraction