refraction

lsst.afw.coord.refraction(wavelength, elevation, observatory, weather=None)

Calculate overall refraction under atmospheric and observing conditions.

Parameters:
wavelengthfloat

wavelength is in nm (valid for 230.2 < wavelength < 2058.6)

elevationlsst.geom.Angle

Elevation of the observation, as an Angle.

observatorylsst.afw.coord.Observatory

Class containing the longitude, latitude, and altitude of the observatory.

weatherlsst.afw.coord.Weather, optional

Class containing the measured temperature, pressure, and humidity at the observatory during an observation If omitted, typical conditions for the observatory’s elevation will be calculated.

Returns:
refractionlsst.geom.Angle

The angular refraction for light of the given wavelength, under the given observing conditions.

Notes

The calculation is taken from [1].

References

[1]

R. C. Stone, “An Accurate Method for Computing Atmospheric Refraction,” Publications of the Astronomical Society of the Pacific, vol. 108, p. 1051, 1996.