SUN/232.8

Starlink Project
Starlink User Note 232.8

Malcolm J. Currie
Brad Cavanagh
Joint Astronomy Centre, Hilo, Hawaii

2004 June

Copyright © 2004 Particle Physics and Astronomy Research Council


ORAC-DR – imaging data reduction

4.1

User Guide



Abstract

ORAC-DR is a general-purpose automatic data-reduction pipeline environment. This document describes its use to reduce imaging data collected at the United Kingdom Infrared Telescope (UKIRT) with the UFTI, UIST, IRCAM, and Michelle instruments; at the Anglo-Australian Telescope (AAT) with the IRIS2 instrument; at the Very Large Telescope with ISAAC and NACO; from Magellan’s Classic Cam, at Gemini with NIRI, and from the Isaac Newton Group using INGRID. It outlines the algorithms used and how to make minor modifications to them, and how to correct for errors made at the telescope.

Contents

1 Introduction
2 Using the pipeline
 2.1 Setting up ORAC-DR
 2.2 Raw Data Formats and Conversions
  2.2.1 ISAAC and NACO Preliminary Conversion
  2.2.2 Classic Cam Preliminary Conversion
 2.3 Running the pipeline
 2.4 Graphical initialisation and operation
 2.5 Display
 2.6 Calibration Information
  2.6.1 Available calibration methods
 2.7 Log files
3 Features of the Primitives
 3.1 Preparation of Single Frames
  3.1.1 Manipulation of Raw Data
  3.1.2 Preliminaries
  3.1.3 Non-linearity Correction
  3.1.4 Electronic Ghosting
  3.1.5 Bad pixels
  3.1.6 Data Variance
  3.1.7 Bias subtraction
  3.1.8 Bias creation
  3.1.9 Chopping
  3.1.10 Post-pre subtraction
  3.1.11 FITS headers
 3.2 Dark subtraction
  3.2.1 Dark creation
 3.3 Flat-fielding
  3.3.1 Flat creation
  3.3.2 Object masking
 3.4 Field-distortion Correction
 3.5 Bias variation
 3.6 Sky Subtraction
  3.6.1 Polarimetry Extraction and Sky Subtraction
 3.7 Automatic Registration
  3.7.1 Moving Targets
  3.7.2 Polarimetry Registration
 3.8 Mosaicking
  3.8.1 Polarimetry Resampling
 3.9 Polarimetry Parameters
 3.10 Near Infra-red Aperture Photometry
 3.11 Mid-infra-red Aperture Photometry
 3.12 Improving the signal-to-noise of Mid-infra-red Data
 3.13 Catalogue Generation
 3.14 eSTAR Integration
 3.15 Tidying
4 Customising Recipes
 4.1 Search paths
 4.2 Anatomy of an imaging recipe
  4.2.1 Hello primitives
  4.2.2 Steering primitive
  4.2.3 Recipe primitives
 4.3 Index files
5 Correcting headers
6 Acknowledgments
7 Copyright and License
A Processing UKIRT data obtained before 2000 August
B File prefixes
C File suffices
D Recipes
 D.1 Classified Recipes
 D.2 Reference documentation
ADDWCS – Creates the valid WCS in the FITS headers of raw data
ARRAY_TESTS – Calculates the readout noises and dark current for UFTI
BRIGHT_POINT_SOURCE – Reduces a bright-point-source photometry observation
BRIGHT_POINT_SOURCE_APHOT – Reduces a bright-point-source photometry observation and performs aperture photometry
BRIGHT_POINT_SOURCE_CATALOGUE – Reduces a bright-point-source photometry observation, producing a catalogue of all sources in the field
BRIGHT_POINT_SOURCE_NCOLOUR_APHOT – Reduces a multi-colour bright-point-source photometry observation and performs aperture photometry.
BRIGHT_POINT_SOURCE_TELE – Reduces a bright-point-source photometry observation using telescope offsets for registration.
CHOP_SKY_JITTER – Reduction of alternating sky-target jitters using interpolated sky subtraction
CHOP_SKY_JITTER_BASIC – Basic reduction of alternating sky-target jitters using interpolated sky subtraction
DARK_AND_BPM – Measures dark current and creates a new bad-pixel mask for UIST
DARK_SUBTRACT – Subtracts a dark frame
DIFFERENCE_STATS – Calculates statistics for Michelle darks in a pairwise manner
EXTENDED_3x3 – Extended-source standard reduction using interpolated sky subtraction
EXTENDED_3x3_BASIC – Basic extended-source standard reduction using interpolated sky subtraction
EXTENDED_5x5 – Extended-source standard reduction using interpolated sky subtraction
EXTENDED_5x5_BASIC – Basic extended-source standard reduction using interpolated sky subtraction
FP – Reduces an 8-frame Fabry-Perot observation
FP_JITTER – Reduces spatially jittered sets of 8-frame Fabry-Perot observations
FP_JITTER_NO_SKY – Reduces a spatially jittered 4-frame Fabry-Perot observation
JITTER_SELF_FLAT – Reduces a “standard jitter” photometry observation using object masking
JITTER_SELF_FLAT_APHOT – Reduces a “standard jitter” photometry observation using object masking, and performs aperture photometry
JITTER_SELF_FLAT_BASIC – Reduces a “standard jitter” photometry observation using just the basic operations for speed
JITTER_SELF_FLAT_CATALOGUE – Reduces a “standard jitter” photometry observation using object masking, and produces a catalogue of all sources in the field
JITTER_SELF_FLAT_NCOLOUR – Reduces a multi-colour “standard jitter” photometry observation using object masking
JITTER_SELF_FLAT_NCOLOUR_APHOT – Reduces a multi-colour “standard jitter” photometry observation using object masking, and performs aperture photometry
JITTER_SELF_FLAT_NO_MASK – Reduces a “standard jitter” photometry observation without object masking
JITTER_SELF_FLAT_TELE – Reduces a “standard jitter” photometry observation using object masking, and telescope offsets for registration
LAMP_FLAT – Creates and files imaging flat fields derived from a calibration lamp
MAKE_BPM – Creates and files a bad-pixel mask from a long-exposure dark
MEASURE_READNOISE – Measures and files the readnoise for UIST from a set of dark frames
MOVING_JITTER_SELF_FLAT – Reduces a “standard jitter” photometry observation of a moving target using object masking
MOVING_JITTER_SELF_FLAT_BASIC – Reduces a “standard jitter” photometry observation of a moving target using just the basic operations for speed
MOVING_NOD_CHOP – Reduces a chopped and nodded observation of a moving target
MOVING_QUADRANT_JITTER – Reduces a “Quadrant Jitter” observation, of a moving target including object masking
NIGHT_LOG – Produces a text file log of a night’s observations
NOD_CHOP – Reduces a chopped and nodded observation
NOD_CHOP_APHOT – Reduces a chopped and nodded observation, and performs aperture photometry
NOD_CHOP_FAINT – Reduces a chopped and nodded observation of a faint source, combining images and smoothing
NOD_CHOP_SCAN – Reduces a chopped and nodded observation in a scan pattern
NOD_SELF_FLAT_NO_MASK – Reduces a “nod jitter” observation
NOD_SELF_FLAT_NO_MASK_APHOT – Reduces a “nod jitter” photometry observation, and performs aperture photometry
NOD_SKY_FLAT_THERMAL – Reduces a “nod jitter” observation creating a flat from sky frames
POL_ANGLE_JITTER – Reduces an imaging polarimetry observation, where waveplate angle iterates at each jitter position
POL_ANGLE_NOD_CHOP – Reduces a chopped and nodded polarimetry observation, where waveplate angle iterates at each jitter position
POL_EXTENDED – Reduces an imaging polarimetry observation of an extended source
POL_JITTER – Reduces an imaging polarimetry observation jittered at each angle
POL_NOD_CHOP – Reduces a chopped and nodded polarimetry observation nodded at each angle
POL_QU_FIRST_NOD_CHOP – Reduces a chopped and nodded polarimetry observation, where waveplate angle iterates in pairs at each jitter position
QUADRANT_JITTER – Reduces a “Quadrant Jitter” observation, including object masking
QUADRANT_JITTER_BASIC – Reduces a “Quadrant Jitter” observation, using just the basic operations for speed
QUADRANT_JITTER_NO_MASK – Reduces a “Quadrant Jitter” observation without object masking
QUADRANT_JITTER_TELE – Reduces a “Quadrant Jitter” observation, using object masking, and telescope offsets for registration
REDUCE_DARK – Averages and files observations as the current dark
REDUCE_FLAT – Reduces an imaging flat field
SKY_AND_JITTER – Reduces a “combined jitter” photometry observation
SKY_AND_JITTER_APHOT – Reduces a “combined jitter” photometry observation, and performs aperture photometry
SKY_FLAT – Creates and files a flat field derived from jittered frames
SKY_FLAT_FP – Creates and files a flat field derived from multiples of four frames using object masking to reduce artifacts
SKY_FLAT_MASKED – Creates and files a flat field derived from jittered frames using object masking to reduce artifacts
SKY_FLAT_POL – Creates and files a flat field derived from eight frames using object masking to reduce artifacts
SKY_FLAT_POL_ANGLE – Creates and files flat fields derived from jittered frames at each waveplate angle, using object masking to reduce artifacts

E Instrument Recipe Notes
 E.1 Classic Cam
 E.2 INGRID
 E.3 IRCAM
 E.4 IRIS2
 E.5 ISAAC
 E.6 Michelle
 E.7 NACO
 E.8 NIRI
 E.9 UFTI
 E.10 UIST
F Internal Headers
 F.1 Translated Headers
 F.2 Steering Headers
G Release Notes—V4.1
 G.1 New recipes
 G.2 Modified recipes
 G.3 Global changes
H Release Notes—V4.0
 H.1 New recipes
 H.2 Modified recipes
 H.3 Global changes
I Release Notes—V3.1-1
 I.1 New recipes
 I.2 Modified recipes
 I.3 Global changes
J Release Notes—V3.0-3
 J.1 New recipes
 J.2 Modified recipes
 J.3 Global changes
K Release Notes—V2.1-0
 K.1 New recipes
 K.2 Modified recipes
 K.3 Global changes
L Release Notes—V2.0-1
 L.1 New recipes
 L.2 Modified recipes
 L.3 Global changes