Instruments

PyReduce supports many instruments out of the box. Custom instruments can be added by creating YAML configuration files.

Supported Instruments

ESO Instruments

• HARPS - High Accuracy Radial velocity Planet Searcher

• HARPS-N - HARPS-North at TNG

• HARPSPOL - HARPS Polarimeter (dual-beam mode)

• UVES - UV-Visual Echelle Spectrograph

• XSHOOTER - Wide-band spectrograph (UVB/VIS/NIR)

• CRIRES+ - Cryogenic IR Echelle Spectrograph

Space Telescopes

• JWST NIRISS - Near Infrared Imager and Slitless Spectrograph

• JWST MIRI - Mid-Infrared Instrument

Other Observatories

• Keck NIRSPEC - Near-IR spectrograph

• Lick APF - Automated Planet Finder

• McDonald - McDonald Observatory spectrograph

• NEID - NN-EXPLORE Exoplanet Investigations with Doppler spectroscopy

ELT Instruments (Simulated)

• METIS - Mid-infrared ELT Imager and Spectrograph (LSS and IFU modes)

• MICADO - Multi-AO Imaging Camera for Deep Observations

• MOSAIC - Multi-Object Spectrograph for Astrophysics, Intergalactic-medium studies and Cosmology

• ANDES_UBV - ArmazoNes high Dispersion Echelle Spectrograph (U/B/V channels)

• ANDES_RIZ - ArmazoNes high Dispersion Echelle Spectrograph (R/IZ channels)

• ANDES_YJH - ArmazoNes high Dispersion Echelle Spectrograph (Y/J/H channels)

• NTE - New Technology Echelle spectrograph

Adding a Custom Instrument

Method 1: YAML Configuration

Create a YAML file defining your instrument:

# myinstrument.yaml
instrument: MyInstrument
telescope: MyTelescope
channels: [default]

# Detector
naxis: [2048, 2048]
orientation: 0
extension: 0
gain: 1.0
readnoise: 5.0

# Header keywords
date: DATE-OBS
target: OBJECT
exposure_time: EXPTIME

# File classification
kw_bias: IMAGETYP
id_bias: bias
kw_flat: IMAGETYP
id_flat: flat
kw_spec: IMAGETYP
id_spec: object

Load it directly:

from pyreduce.instruments import load_instrument

inst = load_instrument("/path/to/myinstrument.yaml")

Method 2: Python Class

For instruments needing custom logic, create a Python class:

from pyreduce.instruments.common import Instrument

class MyInstrument(Instrument):
    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)
        # Custom initialization

    def add_header_info(self, header):
        # Compute derived header values
        header["MJD_MID"] = header["MJD_OBS"] + header["EXPTIME"] / 86400 / 2
        return header

    def get_wavecal_filename(self, header, channel, **kwargs):
        # Return path to wavelength calibration file
        return f"wavecal_{channel}.npz"

Place both files in pyreduce/instruments/{NAME}/ directory (YAML as config.yaml, Python as __init__.py).

Instrument Configuration Fields

Required Fields

Field	Description
instrument	Instrument name
telescope	Telescope name
channels	List of instrument channels/modes
naxis	Detector dimensions [x, y]

Detector Properties

Field	Description
extension	FITS extension (0 or name)
orientation	Rotation/flip code (0-7)
gain	Detector gain (value or header keyword)
readnoise	Read noise (value or header keyword)
dark	Dark current (value or header keyword)
prescan_x	Prescan region in x
overscan_x	Overscan region in x

Header Mappings

These map instrument-specific header keywords to internal names:

Field	Description
date	Observation date
target	Target name
exposure_time	Exposure time
ra, dec	Coordinates
jd	Julian date
instrument_mode	Instrument mode

File Classification

Field	Description
kw_bias, id_bias	Bias file keyword and pattern
kw_flat, id_flat	Flat file keyword and pattern
kw_wave, id_wave	Wavelength calibration keyword and pattern
kw_spec, id_spec	Science file keyword and pattern

See pyreduce/instruments/models.py for the complete schema.

Detector Orientation

The orientation field controls how the raw image is rotated/flipped before processing. Values 0-7 correspond to different transformations:

Value	Transformation
0	No change
1	Rotate 90 CCW
2	Rotate 180
3	Rotate 90 CW
4	Flip horizontal
5	Flip horizontal + rotate 90 CCW
6	Flip vertical
7	Flip horizontal + rotate 90 CW

The goal is to orient the image so that:

• Dispersion direction is horizontal (wavelength increases left to right)

• Cross-dispersion is vertical (orders are stacked vertically)

Reduction Settings

Each instrument has its own settings file at pyreduce/instruments/{INSTRUMENT}/settings.json. This inherits from and overrides pyreduce/instruments/defaults/settings.json. Per-channel overrides can be placed in settings_{channel}.json (e.g., settings_r.json), which inherit from the instrument’s base settings. See Configuration for details.

Multi-Fiber Instruments

Some instruments have multiple fibers per spectral order (e.g., IFU bundles, calibration fibers alongside science fibers). PyReduce supports these via the fibers configuration in config.yaml:

• Fiber groups - Named collections of fibers (e.g., “science”, “cal”, “sky”)

• Bundle patterns - Repeating groups of fibers (e.g., 7 fibers per IFU target)

• Per-order grouping - For echelle instruments with multi-fiber orders

The fibers.use section specifies which traces each reduction step should use:

fibers:
  groups:
    A: { range: [1, 36], merge: average }
    cal: { range: [37, 40], merge: average }
  use:
    science: [A]
    wavecal: [cal]
    norm_flat: all

See Fiber Bundle Tracing for the full configuration reference.