synthesizer.instruments.photometric_instrument

Specialised photometric instrument.

This instrument is designed to hold the attributes required for integrated photometry. It stores a FilterCollection together with optional depth and signal-to-noise definitions for noisy photometric measurements.

Classes

class synthesizer.instruments.photometric_instrument.PhotometricInstrument(label, filters, depth=None, depth_app_radius=None, snrs=None)[source]

Photometric instrument class.

A class containing the attributes and methods required for integrated photometry. It holds the filters defining the instrument transmission curves together with the optional noise information required to generate noisy photometric measurements. It does not include any spatially resolved information such as an image resolution, PSFs, or image-plane noise maps.

filters

The filters defining the photometric response of the instrument.

Type:

FilterCollection

depth

The depth of the instrument, typically in apparent magnitudes. If depths are provided per filter, this should be a dictionary keyed by filter code.

Type:

dict or unyt_quantity, optional

depth_app_radius

The aperture radius for the depth measurement. If omitted but depths and SNRs are provided, the depth is assumed to be a point-source depth.

Type:

unyt_quantity, optional

snrs

The signal-to-noise ratios of the instrument. If values are provided per filter, this should be a dictionary keyed by filter code.

Type:

dict or unyt_quantity, optional

add_filters(filters, psfs=None, noise_maps=None, noise_source_maps=None)[source]

Add filters and optional imaging payloads to the instrument.

Parameters:
  • filters (FilterCollection) – The filters to add to the instrument.

  • psfs (dict, optional) – Optional PSFs keyed by filter code. These are only meaningful for imaging-capable subclasses.

  • noise_maps (dict, optional) – Optional fixed noise maps keyed by filter code. These are only meaningful for imaging-capable subclasses.

  • noise_source_maps (dict, optional) – Optional correlated-noise source maps keyed by filter code. These are only meaningful for imaging-capable subclasses.

property can_do_photometry

Return whether this instrument supports photometry.

property instrument_type

Return the serialised type tag for this instrument.

classmethod load(filepath, **kwargs)[source]

Load a photometric instrument from an HDF5 file.

Parameters:
  • filepath (str or PathLike) – Path to the HDF5 file.

  • **kwargs – Attribute overrides applied after deserialisation.

Returns:

The loaded instrument.

Return type:

PhotometricInstrument

to_hdf5(group)[source]

Write the photometric instrument to an HDF5 group.

Parameters:

group (h5py.Group) – Group into which the instrument should be serialised.