Observation

class specsim.observation.Observation(location, exposure_time, exposure_start, pointing, wavelength, pressure, temperature, relative_humidity)

Bases: object

Model the parameters describing a single spectroscopic observation.

The following parameters can be changed after an Observation object has been created: exposure_time, exposure_start, pointing.

Parameters:

locationastropy.coordinates.EarthLocation

Observatory location on the surface of the earth.

exposure_timeastropy.units.Quantity

Open shutter exposure time for this observation.

exposure_startastropy.time.Time

Time when the shutter opens and the exposure starts.

pointingastropy.coordinates.SkyCoord

Sky position where the telescope boresight is pointing during the observation.

wavelengthastropy.units.Quantity

Array of wavelength bin centers where the simulated spectrum is calculated, with units.

pressureastropy.units.Quantity

Used to create an observing model.

temperatureastropy.units.Quantity

Used to create an observing model.

relative_humidityastropy.units.Quantity

Used to create an observing model.

Attributes Summary

exposure_start	astropy.time.Time: Time when the shutter opens.
exposure_time	astropy.units.Quantity: Exposure time for this observation.
location	astropy.coordinates.EarthLocation: Observatory location.
pointing	astropy.coordinates.SkyCoord: Telescope boresight pointing.
pressure	astropy.units.Quantity: Atmospheric pressure at observatory.
relative_humidity	float: Relative humidity at observatory.
temperature	astropy.units.Quantity: Air temperature at observatory.

Methods Summary

locate_on_focal_plane(sky_position, instrument)

Transform a sky position into focal-plane coordinates.

Attributes Documentation

exposure_start

astropy.time.Time: Time when the shutter opens.

exposure_time

astropy.units.Quantity: Exposure time for this observation.

location

astropy.coordinates.EarthLocation: Observatory location.

pointing

astropy.coordinates.SkyCoord: Telescope boresight pointing.

pressure

astropy.units.Quantity: Atmospheric pressure at observatory.

Used for atmospheric refraction model.

relative_humidity

float: Relative humidity at observatory.

Used for atmospheric refraction model.

temperature

astropy.units.Quantity: Air temperature at observatory.

Used for atmospheric refraction model.

Methods Documentation

locate_on_focal_plane(sky_position, instrument)

Transform a sky position into focal-plane coordinates.

The input sky position can refer to one or more objects.

Parameters:

sky_positionastropy.coordinates.SkyCoord

Position of one or more objects on the sky.

instrumentspecsim.instrument.Instrument

Description of the instrument being simulated.

Returns:

tuple

Tuple (x, y) of focal-plane coordinates given as astropy quantities with length units.