differentialRefraction¶
- lsst.afw.coord.differentialRefraction(wavelength, wavelengthRef, elevation, observatory, weather=None)¶
Calculate the differential refraction between two wavelengths.
- Parameters:
- wavelength
float
wavelength is in nm (valid for 230.2 < wavelength < 2058.6)
- wavelengthRef
float
Reference wavelength, typically the effective wavelength of a filter.
- elevation
lsst.geom.Angle
Elevation of the observation, as an Angle.
- observatory
lsst.afw.coord.Observatory
Class containing the longitude, latitude, and altitude of the observatory.
- weather
lsst.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.
- wavelength
- Returns:
- differentialRefraction
lsst.geom.Angle
The refraction at
wavelength
minus the refraction atwavelengthRef
.
- differentialRefraction