SKA API#


Filters#

class filter.Filter(id)[source]#

Bases: object

compute_flux(spectrum)[source]#

Computes the flux of a spectrum in a given band.

Parameters:

spectrum (ska.Spectrum) – The spectrum to compute the flux of

Returns:

The computed mean flux density

Return type:

float

display_summary()[source]#

Displays a summary of the filter’s properties, including:

  • Filter ID

  • Facility (if available)

  • Instrument (if available)

  • Band (if available)

  • Central wavelength in microns

  • Full Width at Half Maximum (FWHM) in microns

  • Pivot wavelength in microns

plot_transmission(figure=None, black=False)[source]#

Create a plot of the transmission.

Parameters:

  • figure (str) – Path to save a figure

  • black (boolean) – Set True to plot the transmission on a black background (default=False)

Returns:

Matplotlib figure and axe

Return type:

figure, axe

solar_color(filter, phot_sys='Vega', vega=None)[source]#

Compute the color of the Sun between current and provided filter

Parameters:
Returns:

The solar color

Return type:

float

Spectrum#

class spectrum.Spectrum(input=None)[source]#

Bases: object

compute_color(id_filter_1, id_filter_2, phot_sys='Vega', vega=None)[source]#

Computes filter_1-filter_2 color of spectrum in the requested system.

Parameters:

  • id_filter_1 (ska.Filter or str) – The first filter, a SKA Filter object of a filter unique ID (see SVO filter service)

  • id_filter_2 (ska.Filter) – The second filter, a SKA Filter object of a filter unique ID (see SVO filter service)

  • phot_sys (str) – Photometric system in which to report the color (default=Vega)

  • vega (ska.Spectrum) – The spectrum of Vega

Returns:

The requested color

Return type:

float

copy()[source]#

Make a deepcopy of the SKA.Spectrum object.

from_blackbody(T)[source]#

Create a SKA spectrum of a blackbody at temperature T.

Parameters:

T (float) – The temperature of the blackbody in Kelvin

from_csv(file)[source]#

Create a SKA spectrum from a CSV file.

Parameters:

file (str) – Path to a CSV file containing the spectrum

from_dataframe(df)[source]#

Create a SKA spectrum from a pandas DataFrame.

Parameters:

df (pd.DataFrame) – A DataFrame containing the spectrum. Columns must be Wavelength (in micron), and either Flux or Reflectance.

from_numpy(arr, reflectance=False)[source]#

Create a SKA spectrum from a numpy array.

Parameters:

  • arr (np.ndarray) – A numpy array containing the spectrum. Columns must be Wavelength (in micron), and either Flux or Reflectance.

  • reflectance (boolean) – Set True if the input is a reflectance spectrum (default=False)

from_taxonomy(type)[source]#

Create a SKA reflectance spectrum from an asteroid template spectrum (Mahlke+2022 taxonomy).

Parameters:

type (str) – The name of the spectral type (A, B, C, D, E, K, L… V, Z)

plot(filters=None, figure=None, black=False)[source]#

Create a plot of the spectrum.

Parameters:

  • figure (str) – Path to save a figure

  • black (boolean) – Set True to plot the transmission on a black background (default=False)

Returns:

Matplotlib figure and axe

Return type:

figure, axe

reflectance_to_color(id_filter_1, id_filter_2, phot_sys='Vega', vega=None, sun=None)[source]#

Computes filter_1-filter_2 color for a reflectance spectrum.

Parameters:

  • id_filter_1 (ska.Filter or str) – The first filter, a SKA Filter object of a filter unique ID (see SVO filter service)

  • id_filter_2 (ska.Filter) – The second filter, a SKA Filter object of a filter unique ID (see SVO filter service)

  • phot_sys (str) – Photometric system in which to report the color (default=Vega)

  • vega (ska.Spectrum) – Spectrum of Vega

  • sun (ska.Spectrum) – Spectrum of the Sun

Returns:

The requested color

Return type:

float

reflectance_to_flux(sun=None)[source]#

Convert reflectance to flux by multiply by Solar spectrum.

Parameters:

sun (ska.Spectrum) – Spectrum of the Sun

Returns:

A copy of the input Spectrum, in flux units

Return type:

float

SVO Tools#

svo.download_filter(id, force=False)[source]#

Download a filter VOTable from SVO Filter Service

Parameters:

  • id (str) – The unique SVO filter identifier to be downloaded

  • force (bool) – If True, the filter VOTable will be downloaded even if it is already cached

Returns:

The path to the filter VOTable file

Return type:

str

svo.download_filter_list()[source]#

Retrieve the list of filter IDs from `SVO Filter Service <http://svo2.cab.inta-csic.es/theory/fps`__

Returns:

The list of filter IDS

Return type:

list

svo.load_filter_list()[source]#

Read all filter IDs from a cache list

Returns:

The list of filter IDS

Return type:

list