photErrModel

lsst.validate.drp.photerrmodel.photErrModel(mag, sigmaSys, gamma, m5)

Model of photometric error for a single visit.

The model is described in the LSST Overview paper: http://arxiv.org/abs/0805.2366v4.

Photometric error of a single visit (Eq. 4):

Where random uncertainty is (Eq. 5):

$$\sigma_\mathrm{rand}^2 = (0.04 - \gamma) * x + \gamma * x^2~[\mathrm{mag}^2]$$

and $x = 10^(0.4*(m-m_5))$.

Parameters:

mag : astropy.unit.Quantity

Source magnitude.

sigmaSq : astropy.unit.Quantity

Systematic photometric error (magnitude).

gamma : astropy.unit.Quantity

Proxy for sky brightness and readout noise (dimensionless).

m5 : astropy.unit.Quantity

5-sigma depth (magnitude).

Returns:

sigma : astropy.units.Quantity

Photometric error for a single visit.