AnalyticAstrometryModel

class lsst.validate.drp.matchreduce.AnalyticAstrometryModel(matchedMultiVisitDataset, brightSnr=100, medianRef=100, matchRef=500)[source]

Bases: lsst.validate.drp.base.BlobBase

Serializable model of astronometry errors across multiple visits.

astromRms=Cheta/SNR+σsys
Parameters:

matchedMultiVisitDataset : MatchedMultiVisitDataset

A dataset containing matched statistics for stars across multiple visits.

brightSnr : float, optional

Minimum SNR for a star to be considered “bright”.

medianRef : float, optional

Median reference astrometric scatter in millimagnitudes

matchRef : int, optional

Should match at least matchRef stars.

Notes

The scatter and match defaults are appropriate to SDSS are the defaults
for medianRef and matchRef

For SDSS, stars with mag < 19.5 should be completely well measured.

Attributes

brightSnr (float) Threshold SNR for bright sources used in this model.
C (float) Model scaling factor.
theta (float) Seeing (milliarcsecond).
sigmaSys (float) Systematic error floor (milliarcsecond).
astromRms (float) Astrometric scatter (RMS) for good stars (milliarcsecond).