This website is kept for archival purposes only and is no longer updated.
The site was frozen as of 10/2022. Please use the GitHub site instead.

Links to other Astronomy and IDL related sites

General IDL Resources

General Information about IDL from NV5 Geospatial.
NV5 Geospatial is the manufacturer of IDL, and this is the Web site to obtain a summary of IDL functionality, information about pricing and supported machines, or to download an IDL demo. (Previous companies that developed IDL include L3Harris Geospatial, Exelis VIS, ITTVIS, and RSI.) The site also contains a section of IDL Help Articles on using IDL, and supplemental packages. The current IDL version is 8.8.2, and the IDL documentation is available online.
IDL Forums
The main forum for discussion and questions about the IDL language is the Google group idl-pvwave . This site is a continuation of the Usenet group comp.lang.idl-pvwave , which was abandoned at the end of 2017 due to a heavy attack by spammers. Thanks to P. Penteado, a searchable archive of comp.lang.idl-pvwave messages between 1991 and 2017 is available at the comp.lang.idl-pvwave archive site. NV5 Geospatial maintains a less active User forum . Frequently asked questions (FAQ) about IDL are probably most likely to be answered in one of the several hundred (!) IDL Programming Tips and Tricks available in David Fanning's Coyote's Guide to IDL Programming.
Coyote's Guide to IDL Programming
Although independent IDL consultant David Fanning retired in November 2014, his Coyote's Guide to IDL Programming website remains the first place to look for advice on IDL programming. The IDL Astronomy Library includes a subset of the "Coyote" IDL library, and anyone using IDL direct graphics is encouraged to download this library. David is also the author of the books IDL Programming Techniques" (2000) and Coyote's Guide to Traditional IDL Graphics (2011).
Direct Graphics Plotting :
In 2010, IDL 8.0 introduced a new plotting system "function graphics" which should probably be used for all new development. However, several groups have written code to enhance the capabilities of the older "direct graphics". David Fanning's CGZPLOT allows one to zoom and pan across a plot. The FUSE group in Paris has written Xiplot (V2.18 Oct 2014) which can read a FITS binary table and allows some spectral manipulation. The program in the TARA package includes fitting and shifting procedures. The well-documented plotting widget GRAFFER by James Tappin (U. of Birmingham), was last updated in September 2021. Pavel Romashkin's IDL Library includes a 2-D plotting DISPLAY widget (Version 3.2 last updated May 2013). The Coyote Graphics Plot Gallery allows one to click on numerous example plots to see the IDL code used to create it. Leonardo Ubeda (STScI) has developed AstroPlotLib which is a similar, but more astronomy-oriented, clickable plot gallery.
ICG (Institute for Chemistry and Dynamic of the Geosphere) Library 
This large library of IDL programs at the ForschungsZentrum Jülich in Germany includes procedures for conversion of IDL variables and structures into html code, plotting, programming tools, widgets, and a interface to a facsimile differential equation solver for chemical reactions. Version 13.0 was released in November 2013.
JHU/APL(Johns Hopkins University/Applied Physics Laboratory) IDL Library
Ray Sterner created this large general IDL library at the JHU Applied Physics Laboratory. The site also includes several IDL tutorials. Last updated Oct 2014.
Ken Bowman's IDL page
Ken Bowman (Texas A&M) is the author of the 2005 book An Introduction to Programming with IDL for beginning programmers.
Database access
NV5 Geospatial sells DATAMINER , an add-on module that allows one to connect to multiple databases from IDL. Marc Buie developed an MySQL interface using bidirectional pipes. Sergey Koposov has developed idl-sql, which allows one to execute SQL queries from IDL and retrieve the results of these queries in IDL. It uses the IDL-Java bridge and the Java Database Connectivity (JDBC). He has also adapted software from Erin Sheldon for accessing a Postgresql database, that does not use the IDL-Java bridge.
Rob Dimeo's IDL Library
This IDL library the National Institute of Standards and Technology (NIST) is particularly useful for PAN a general-purpose curve fitting utility with a graphical user interface (last updated May 2005), an IDL implementation of a genetic algorithm, and a visualization of 1d quantum dynamics (last updated July 2007). There is also an IDL course manual providing an introduction to widget and object programming
Michael Galloy's Resources for IDL Developers
This readable blog by a former IDL instructor and consultant discusses IDL (and non-IDL) techniques for visualization and information design. Mike also maintains IDLDOC , a utility for producing documentation for any valid IDL code, rIDL , an IDL command line replacement similar to ipython, mgunit a framework for unit testing for IDL, and an excellent personal IDL library . Mike is the author of Modern IDL: A Guide to IDL programming , which was last revised in Sep 2015 to include updates on IDL 8.5.
David Grier's IDL Library
This IDL library at New York University includes code to acquire images from video cameras, and code for tracking features in images.
Mark Hadfield's Motley IDL Library
This active GitHub site at the National Institute of Water and Atmospheric Research in New Zealand includes several Object Graphics classes, a base class for widget applications and several applications built on it, functions that make it easy to represent scaled data on axes, classes for accessing netCDF files and several utility routines.
Ronn Kling Consulting
This site is probably most useful for its C code available as DLM (dynamically linked modules) to enhance IDL capabilities. Ronn Kling is the author of the books Application Development with IDL (1999), Calling C and C++ from IDL (2001), Power Graphics with IDL(2002), Object-Oriented Programming with IDL (2010), and most recently Using Python from IDL (2014)
Craig Markwardt's IDL Library
This IDL library at the University of Wisconsin includes many well-documented plotting, utility, ephemeris, mathematics and robust curve-fitting procedures. Last updated Jan 2017.
Mathew Craig's TeXtoIDL Software
This software translates the TeX character set into the IDL plotting symbol codes for direct graphics. Version 2.1.2 updated June 2004. This code has been mostly supplanted by CGSYMBOL in the Coyote Graphics Library
David Windt's IDL Library
This IDL library at Reflective X-ray Optics LLC includes procedures for plotting, curve fitting, and image analysis. Also includes IMD, a widget tool for analysis of optical multilayers. Last updated July 2014
IDL Text Editor modes
Although IDL comes with an Eclipse-based development environment, some users prefer a traditional text editor with an IDL language mode. The Emacs mode for IDL was written by JD Smith at the University of Arizona. Version 6.5 was released in January 2011 and is included in the current Emacs release . An IDL .plist mode for TextWrangler/BBEdit on the Mac is available from Will Powell. Alfred de Wijn wrote code to improve the VIM editor support for IDL. David Higgins wrote an XML file to provide IDL support for notepad++
IDL Wavelet Software:
Since V8.0, IDL includes a wavelet toolkit (which was formerly available as a separate addon). Christopher Torrence and Gilbert Campo have written a Practical Guide to Wavelet Analysis with applications in geophysics, and include some IDL software. Multi Resolutions Ltd. sells a software package for Multiresolution Analysis which includes about 5000 lines of IDL code.
Free IDL Clones
The following two actively developed languages are similar to IDL, though they may lack some features, and have limited documentation. The GNU Data Language (GDL) is an Open Source clone of IDL, currently at Version 1.0.1 (Oct 2021). The Fawlty Language (FL) is an IDL8 compatible compiler, currently at version 0.79.50 (July 2021).
Commercial Add-ons
Some companies sell products to enhance the capabilities of IDL. l3Harris Geospatial sells the Advanced Math & Statistics Library (formerly "IDL Analyst") which adds the capabilities of the IMSL(TM) C Numerical Library to IDL

Astronomy IDL Software Sites

ACS (Advanced Camera for Surveys) analysis software
Maurizio Paolillo (University of Napoli) has written multiking_ to add a simulated PSF or Globular Clusters to HST ACS flt images.
Adaptive Optics Software
The Center for Adaptive Optics (CfAO) at the Lick Observatory provides links to several AO packages which use IDL including an AO Simulation Package written by Francois Rigaut, StarFinder software (v1.6f) first written in August 2000 to analyze stellar fields from AO images, and Virtual Telescope Software to simulate telescope observing parameters (e.g. S/N). The CAOS - Code for Adaptive Optics System system at Arcetri Observatory is composed of a graphical programming environment, which can load different packages including the CAOS software package (V7.0, June 2016), the MAOS (Multiconjugate Adaptive Optics Simulations) package, and the AIRY image reconstruction package. Tuan Do (UCLA) has written Fourier Optics GUI (fgui), an IDL widget that computes and displays the effect of adding phase aberrations for apertures of different shapes
AIT (Astronomical Institute of Tübingen) IDL software
The AIT Library includes IDL procedures for analyzing X-ray astronomy data, and provides a nice up-to-date interface to the IDL Astronomy Library. It also provides access to there TRIPP (Time Resolved Imaging PHotometry Package) software, and to procedures for time-series analysis.
Aladin Interface
Aladin is an interactive software sky atlas allowing the user to visualize digitized astronomical images, superimpose entries from astronomical catalogues or databases. An IDL interface is available, which uses the IDL_Java bridge to allow users to launch Aladin, load images, load tables, select object in tables, etc. from the IDL prompt.
ATV Image Display Tool
ATV is an image display widget written by Aaron Barth (UC Irvine), that is modeled after the SAOimage display package. The current version is 3.0b8, last modified 28-Nov-2016 and includes astronomical coordinate tracking, radial profile plots, choice of coordinate systems, and the ability to read FITS extensions. A modified version of ATV called SMTV which includes WCS overlays, DS9 region files, and image cube options is available in the SMART data analysis package.
Jeremy Bailin's IDL Utilities (JBIU )
Jeremy Bailin makes available a small library of astronomy and miscellaneous routines. Last updated July 2016 (jbiu-1.2.1.tgz)
BANYAN (Bayesian Analysis for Nearby Young AssociatioNs)
BANYAN is a Bayesian analysis tool to determine the membership probability of stars to nearby young associations. This algorithm is based on a comparison of Galactic position (XYZ) and space velocity (UVW), using a Bayesian classifier.
Chris Beaumont's IDL Code
Chris Beaumont (U. of Hawaii) makes available some of his IDL routines, including procedures for Markov Chain Monte Carlo simulations, kinematic distances, robust methods, and vector and stack classes. Last updated August 2011.
Gonzalo Aniano (Princeton) and colleagues have written, a routine to generate multiwavelength images with a common PSF.
CosmoStat. Software
The CosmoStat group at the AIM laboratory of CEA/Saclay has developed a large collection of mainly IDL based software for statistics and cosmology. In particular, the Interactive Sparse Astronomical data Analysis Package (ISAP) includes well-documented IDL code for analysis of data on the sphere.
Atomic Database Programs
CHIANTI consists of a suite of IDL programs and a database of atomic data for calculating synthetic spectra in the region between 50 A and 1100 A. This site at the Naval Research Laboratory (NRL) includes extensive documentation. Version 9.0 was released in March 2019. The Package for Interactive Analysis of Line Emission (PINTofALE) at the Harvard Center for Astrophysics (CFA) uses CHIANTI for the analysis of spectroscopic data from optically-thin coronal plasmas. Version 2.97 was last updated November 2016. The Chandra X-ray Center has an IDL interface to Version V2.0.0 (December 2003) of the Atomic Database (ATOMDB) for X-ray spectral modeling. Ashkbiz Danehkar has developed ATOMNEB ,.an IDL library for atomic data of ionized nebulae. P.G. Judge (HAO) has developed HAOS-DIPER to manipulate data for neutral atoms and atomic ions in space plasmas, notably solar and stellar atmospheres. Version 1.1 was released in Jan. 2013.
Cosmology Routines
The IDL cosmology packages ICOSMO (Refregier et al. 2011) and RED (Moustakas and Moustakas 2002) are no longer actively maintained but the ICOSMO source code and the RED source code are still available. Marco Barden (MPIA) has written FERENGI ( Full and Efficient Redshifting Ensemble of Nearby Galaxy Images) which uses the K corrections to model the appearance of a galaxy at any redshift. Ivan Baldry (Liverpool John Moores) has developed the IDL code AUTOZ, to automatically determine the redshift from (AAT) spectra. Last updated April 2014.
Dan Bramich (ESO) has released a library of mainly astronomy-related IDL procedures including routines for image differencing, Delaunay triangle source matching, and synthesis functions. The entire library is available for a one-time subscription fee, but a subset of the DanIDL routines is available in the public domain via the DanIDL-Lite library. Version 3.0 of DanIDL-Lite was released in November 2017.
James Davenport's IDL Code
James Davenport (Western Washington U.) makes available some of his IDL routines, for analyzing light curves and flares, binning and smoothing.
Education and Instruction Astronomy IDL Pages
L. Nicastro (INAF-IASF) presented an IDL primer course in June 2009.
Exoplanet Software
Jason Wright (Cornell) and Andrew Howard (Berkeley) make available RVLIN, an IDL package for efficient fitting of multi-planet Keplerian models to radial velocity and astrometric data. Version 2.15 was released in June 2015. The site also includes a robust parameter uncertainty estimator for RVLIN (V1.1 released October 2012). Jason Eastman (Ohio State) and colleagues make available EXOFAST a robust suite of IDL routines designed to fit exoplanetary transits and radial velocity variations and characterize the parameter uncertainties and covariances with a Differential Evolution Markov Chain Monte Carlo method. J. Zachary Gazak (U. of Hawaii) and colleagues developed the Transit Analysis Package (TAP) an IDL Widget which utilizes Markov Chain Monte Carlo (MCMC) techniques to fit transit light curves. R. Iglesias-Marzoa (Universidad de La Laguna) has written RVFIT, which fits non-precessing Keplerian radial velocity (RV) curves for double-line and single-line binary stars or exoplanets using an adaptive simulated annealing algorithm.
Fermi Analysis Software
The Fermi Science team makes available rmfit, which will create lightcurves, fit backgrounds, and fit single or multiple spectra for NaI and BGO detectors. It was written by R. Preece, M. Briggs, and V. Connaughton (U. of Alabama, Huntsville).
GALAPAGOS-2: Galaxy Analysis over Large Areas: Parameter Assessment by GALFITting Objects from Sextractor
Marco Barden (University of Innsbruck) originally developed the GALAPAGOS package, which combines object detection with SExtractor and light profile modelling with GALFIT to help automate the analysis of large astronomical imaging survey data sets. The MegaMorph project (H�u�ler, Bamford and Vika) has added many new features to this code to create GALAPAGOS-2
Group K IDL User's Library
This is a collection of general purpose and high energy astrophysics routines written by members of the particle astrophysics group at the Stanford Linear Accelerator. A good site for mathematics and statistics routines. Last updated 04/99.
The Hammer An IDL Spectral Typing Suite
The Hammer spectral typing algorithm was originally developed for use on late-type SDSS spectra, but has subsequently been modified to allow it to classify spectra in a variety of formats with targets spanning the MK spectral sequence..Written and maintained by Kevin Covey (Harvard), Andrew A. West, and John J. Bochanski. V1.2 was written in Dec 09.
Joe Harrington's IDL packages
Joe Harrington (U. of Central Florida) make several IDL packages available including DeFringeflat - a wavelet transform to defringe flats, Optspecextr - optimal extraction of a point source spectrum, "Synthspec" for producing mock spectra from a spectrograph, and "MaskInterp" for repairing bad pixels using a non-linear surface fit to neighboring good pixels.
Integral Field Spectroscopy Software
I-Ting Ho (Hawaii) and colleagues have written LZIFU an IDL toolkit for fitting multiple emission lines simultaneously in integral field spectroscopy. Christer Sandin (Potsdam) and collaborators have written P3d , a general data-reduction IDL widget for analyzing data from fiber-fed integral field spectrographs (IFSs). V2.7 released Aug 2020. Adam S. Bolton (IfA) and Scott Burles (MIT ) have written kungifu a set of IDL software routines designed for the calibration and reduction of fiber-fed integral-field unit (IFU) astronomical spectroscopy. F. F. Rosales-Ortega (Cambridge, IEM-CSIC) has written PINGSoft2, set of IDL routines (last updated November 2012) designed to visualise and interactively manipulate integral field spectroscopic data. The software was originally designed to handle Califa data. Mark Westmoquette (UCL) has modified the PAN curve-fitting widget from Rob Dimeo for use with astronomical spectra. An IDL package for 3D Fabry-Perot Data Reduction Software was developed at the Universit� de Montr�al and was designed for the FaNTOmM integral field spectrometer. Rogemar A. Riffel (Universidade Federal de Santa Maria) has written PROFIT (Emission-line PROfile FITting routine) to do automated fitting of emission-line profiles by Gaussian curves or Gauss-Hermite series optimized for use in Integral Field and Fabry-Perot data cubes. V1.3 released April 2015. David Rupke (Rhodes College) has written IFSRED , a general-purpose library for reducing data from integral field spectrographs. He has also written IFSFIT , an IDL library for fitting the continuum, emission lines, and absorption lines in integral field spectra
Spitzer and Infrared Astronomy software
The Spitzer Science Center distributes several IDL tools including the large SMART (IRS Spectroscopy Modeling Analysis and Reduction Tool) package (Version 8.2.9 released September 2014). This package is designed to analyze data from the Infrared Spectrograph (IRS) but includes many useful general astronomy tools. JD Smith (U. of Arizona) developed CUBISM , a tool for constructing spectral cubes, maps, and arbitrary aperture 1D spectral extractions from sets of mapping mode spectra taken with Spitzer's IRS spectrograph (V1.8 released July 2011). He also makes available PAHFIT , an IDL tool for decomposing Spitzer IRS spectra of polyaromatic hydrocarbon (PAH) emission sources. (Version 1.2 released in October 2006). Matthieu Bethermin and colleagues at the Institut d'Astrophysique Spatiale (IAS) make available IDL software for analysis of infrared galaxies, including stacking of Spitzer images (V1.0 release Dec 2009), PSF fitting with position priors (V1.0 release May 2010), and a model of the infrared sky. Sarah Kendrew (Leiden Observatory) has written IDL code to compute the sensitivity of a ground-based mid-infrared instrument, originally written for the proposed Mid-Infrared E-ELT Imager and Spectrograph (METIS) . Dan Li (U. of Florida) has written IDEALCam ( Interactive Data Reduction and Analysis for CanariCam ), an efficient tool to access, reduce, and analyze multi-extension mid-IR FITS files. The Instrument Definition Teams for the Infrared Space Observatory (ISO) developed their interactive analysis software in IDL, and the software and documentation can be accessed from the ISO Data Center in VillaFranca, Spain. Access to the ISO software in the U.S. is available from the Infrared Processing and Analysis Center (IPAC) . The Infrared Science Archive (IRSA) provides IDL tools for querying their catalogs and reading and writing the IPAC table format.
Instrument Reduction Pipelines
The MASE: (MAGE Spectral Extractor) IDL software was written by John Bochanski (MIT) and collaborators to reduce data from the Magellan Echellete Spectrograph (MAGE) . Reduction steps include flatfielding, spectral extraction, wavelength and flux calibrations. V1.0 was released in Sep 09. The MMIRS data reduction pipeline is an IDL software package to reduce long-slit and multi-slit spectroscopic observations collected using the MMT and the Magellan Infrared Spectrograph (MMIRS). Last updated Apr 2020.
Interferometry: Optical and Infrared
The Optical Interferometer Script Data Reduction package Oyster was developed at the US Naval Observatory as a comprehensive system for displaying, editing, averaging, calibrating, and modeling interferometry data. V8.28 was released in October 2019 and is available by contacting the author. The MIDI Interactive Analysis (MIA) software was developed at the Max-Planck-Institut für Astronomie (MPIA) to analyze data from the MID-infrared Interferometric instrument (MIDI) on the Very Large Telescope Interferometer (VLTI). Version 2.0 was released Oct 2012. John Monnier (U. of Michigan) has developed an IDL interface to (OIFITS) to read OIFITS (Optical Interferometry FITS) data, which is a proposed standard for storing optical interferometry data in FITS binary tables. It was last updated in Jan 2013.
Jason Prochaska's XIDL software
This site at the Lick Observatory includes procedures for modeling and analyzing spectra of damped Ly Alpha absorption lines (DLA), but includes some routines generally useful for spectroscopy and photometry. V3.0 was released in June 2010.
LACOSMIC (LAplacian COSMIC ray identification) software
LACOSMIC (Van Dokkum 2001, PASP, 113, 1420) is an algorithm for robust cosmic ray identification using Laplacian edge detection. IDL code is included at Peter van Dokkum's Yale website for the case of imaging.
Marc Buie's Astronomy IDL software (CCDPHOT, ITOOL)
Includes the IDL widget programs CCDPHOT to process CCD data, and ITOOL for general image processing, which were developed at Lowell Observatory for the processing of solar system CCD images. Contains many useful IDL procedures for astronomical analysis. Continuously updated.
Markus Feldt's Astronomy Packages
Markus Feldt at MPIA Heidelberg makes available two IDL packages: SimVLTI for simulating observations with the Very Large Telescope Interferometer (VLTI) in Paranal, Chile, and A/O (Version 0.37.2) a package to analyze data taken by array cameras, in particular the ALFA/OMEGA (Adaptive optics with a Laser For Astronomy) system.
Cosmic Microwave and Far-Infrared Analysis Software
The IDL software package for the Wilkinson Microwave Anisotropy Probe (WMAP) (Version 3.1 updated June 2014) includes time/coordinate conversion and pixelization algorithms useful for microwave background analysis. WMAP and most other CMB experiments use the HEALPix (Hierarchical Equal Area isoLatitude Pixelisation) pixelization scheme, and the HEALPix collaboration includes IDL software for fast and accurate statistical and astrophysical analysis of full-sky data sets (Version 3.80 updated June 2021). Older code includes the analysis software for the COsmic Background Explorer (COBE) which was primarily written in IDL (Version 4.1 released June 1999). Scanamorphos is an IDL software to build maps from scan observations made with bolometer arrays, in particular with the PACS and SPIRE photometers onboard the Herschel space telescope. Version 25 was released in August 2016. FTFitter is an IDL widget for fitting FTS spectra from the SPIRE (Spectral and Photometric Imaging Receiver) instrument on Herschel. Version 1.93 was released in Jan 2015.
MIMIR Data Reduction Software
MIMIR is a near-infrared instrument built at Boston University and Lowell Observatory. The software includes a GUI-based IDL "project" that performs all the raw data intake, quality testing, bookkeeping, dark/flat/linearity corrections, and wavelength calibration needed to generate "science ready" images. Version 3.4.5 was released in Feb 2020.
Michelle Cappellari's IDL programs
This site maintained by Michele Cappellari (University of Oxford) contains several excellent IDL packages. MGE_FIT_SECTORS will fit Multi_gaussian Expansion (MGE) models to galaxy images, to be used as a parameterization for a galaxy surface brightness. VORONOI_2D_BINNING will bin two-dimensional data to a constant signal-to-noise ratio per bin (last updated April 2016). PPXF will extract galaxy stellar kinematics from absorption line spectra (last updated August 2016). Davor Krajnović (Oxford University) makes available the KINEMETRY package, for analysis of 2D maps of (kinematic) moments of the line-of-sight-velocity distribution (LOSVD).
Paulo Penteado's IDL Library
Paulo Penteado (Northern Arizona U.) makes available some of his IDL routines, including those dealing with function graphics, convolution, and ground observing tools. Last updated January 2016.
Photoionization Modeling
Bent Groves (MPIA-Heidelberg) has written ITERA (IDL Tool for Emission-line Ratio Analysis) widget tool which allows one to plot ratios of any strong atomic and ionized emission lines as determined by standard photoionization and shock models. Last updated October 2009.
Planetary Data System (PDS) format readers
The Small Bodies Node (SBN) at the University of Maryland provides IDL procedures for reading images and tables in the PDS format, which can be downloaded at the GitHub repository The Observatory of Paris provides an alternate IDL procedure for reading PDS files as part of the EuroPlaNet project, that is especially well-suited for spectral cubes. Version 3.1 was released in June 2013.
Photometric Data Extractor (PODEX)
PODEX is an IDL widget written by Thomas Kallinger (Institut fur Astronomie, Vienna) to obtain light curves from photometric CCD data
PROPER IDL-based simulation of light through an optical system.
PROPER is a library of IDL routines developed by John Krist (JPL) to simulate the propagation of light through an optical system. It automatically applies near and far field propagators. It includes functions to create complex apertures, model a deformable mirror, and create amplitude and phase aberrations (Zernike, PSD-defined, user-generated map). A detailed manual is available. Version 3.2.5 was released in April 2021.
QSFIT - Quasar Spectral FITting package
QSFIT is an IDL package written by Giorgio Calderone and Luciano Nicastro (INAF) to automatically perform spectral analysis of Active Galactic Nuclei (AGN) optical/UV spectra. The current version is 1.3
Radio Astronomy Software
IDL procedures have been developed at the National Astronomy and Ionospheric Center's Arecibo Observatory for reducing spectral line and mapping data. PACERMAN (Polarisation Angle CorrEcting Rotation Measure ANalysis) is an IDL code to calculate Faraday rotation measure maps from multi-frequency polarisation angle data (V1.2 released August 2005). GBTIDL is an interactive package for reduction and analysis of spectral line data taken with the Robert C. Byrd Green Bank Telescope (GBT). Version 2.10.1 was released in Sep 2016. TMBTIDL is an IDL package for the reduction of single dish radio astronomy data. Version 8.0 was released in October 2015. Erik Rosolowsky (CFA) and Adam Leroy (UC/Berkeley) have developed the CPROPS package. to characterize molecular cloud properties in a molecular line data cube. Their software uses the CLUMPFIND algorithm developed by Jonathan Williams (Hawaii) to find local peaks in data cubes. MIR is a complete IDL package to reduce data obtained with the Smithsonian Submillimeter Array (SMA) Last updated June 2021.
SGP-IDL Package for the single and multiple deconvolution of 2D images corrupted by Poisson noise
SGP-IDL was developed by M. Prato (Modena) and colleagues. It computes a deconvolved image by early stopping of the scaled gradient projection (SGP) algorithm for the solution of the optimization problem coming from the minimization of the generalized Kullback-Leibler divergence between the computed image and the observed image. The algorithms have been implemented also for Graphic Processing Units (GPUs).
Shapelets IDL Software
Shapelets are a complete, orthonormal set of 2D basis functions constructed from Laguerre or Hermite polynomials weighted by a Gaussian which can be used to model any image, and are especially useful for galaxy modeling. Richard Massey and Alexandre Refregier (CalTech) make their well-documented IDL shapelet code publicly available (Version 2.2 released May 2008). Dave Goldberg (Drexel U.) uses shapelets for his IDL flexion code for analyzing distortions due to gravitational lensing.
SIMPLE Imaging and Mosaicking Pipeline
SIMPLE is an IDL based data reduction package for optical and near-IR blank-field imaging observations developed by W.H. Wang (NRAO). While it is currently optimized for the MOIRCS camera on Subaru and the WIRCAM camera on CFHT, its subroutines are written as generally as possible. Version 1.1 was released in Aug. 2008
Sloan Digital Sky Survey (SDSS) IDL Software
Some researchers from SDSS institutions keep their analysis software for SDSS images and spectra publicly available. Erin Scott Sheldon maintains the SDSSIDL library , which includes IDL wrappers to C/C++ routines for postgres database interface, efficient file input/output, and efficient ra/dec searching using the Hierarchical Triangular Mesh (HTM). V1.7 was released in January 2012. The IDL SDSS spectroscopy software can be downloaded as tar files. Mike Blanton (NYU) has written IDL code to calculate galaxy K-corrections and spectral energy distributions (Version 4.2 released in February 2010). Vivienne Wild & Paul Hewett (Institute of Astronomy) make IDL code available for removing residual sky features (OH lines) from SDSS spectra. Her page also includes IDL code for iterative robust and iterative principal component analysis (PCA). David Hogg (NYU) maintains a page with IDL code for proper color representation of multi-band imaging.
SME (Spectroscopy Made Easy)
SME is IDL software and a compiled external library by J. Valenti (STScI) that fits an observed high-resolution stellar spectrum with a synthetic spectrum to determine stellar parameters. The latest version is 574, released Feb 2020. Nikolai Piskusnov (Uppsala) makes available the IDL package REDUCE (Piskunov & Valenti 2002, A & A, 385, 1095) and also includes a small general IDL library. Additional IDL programs for modeling stellar spectra are made available by Oleg Kochukhov (Uppsala). These include BINMAG a visualization program to compare observed and model spectra. V6.4 of BINMAG was released in Feb 2020.
Solar Software Library
Includes a very large number of general and solar-related IDL procedures accessible via FTP . Download instructions are available at the Solarsoft Installation Guide, and a SolarSoft search page is available. Dominic Zarro has written IDL code using IDL Map Software for Analyzing Solar Images , and an introduction to Programming with IDL Objects: Why and how to do it". Additional help is available on using the Solar IDL software with GOES (Geostationary Operational Environmental Satellites). Sergey Anfinogentov (Institute of Solar-Terrestial Physics) have developed a Solar Bayesian Analysis Toolkit (SoBAT)New to compare data and models using Bayesian inference
Solar Stellar Spectrograph (SSS) Software
The SSS is a project dedicated to long-term observations of the Sun and Sun-like stars. The well-documented object-oriented software reduction code carries out the steps ( e.g. flat-fielding, scattered light removal, spectrum extraction) and includes classes available for general use.
SpecPro An IDL Program for Viewing and Analyzing Astronomical Spectra
SpecPro is an interactive program written by D. Masters and P. Capak for viewing and analyzing spectra, particularly in the context of modern imaging surveys. In addition to displaying the 1D and 2D spectrum, SpecPro can simultaneously display available stamp images as well as the spectral energy distribution of a source. Version 3.0 was released in February 2012.
SpexTool: Infrared Cross-dispersed Spectrograph Software
This page contains SpexTool (V4.1 Jan 2016), an IDL-based spectral extraction package written by Vacca, Cushing & Rayner (Institute for Astronomy, Hawaii) for the Spex instrument, a 0.8 - 5.5 micron cross-dispersed spectrograph on the NASA Infrared Telescope Facility.
Stellar Locus Regression
FW High (Harvard/CFA) and co-workers make available an IDL package to directly adjust instrumental broadband optical colors of stars to bring them into accord with a universal stellar color-color locus. Version 1.1 was released in April 2009.
STOOLS ( IDL Tools for Spectroscopic Analysis)
Carlos Allende Prieto (U. of Texas) makes available some of his IDL software, including a reader for IRAF formatted echelle spectra, and cross-correlating spectra to determine radial velocities.
TAME ( Tools for Automatic Measurement of Equivalent Width )
TAME is an IDL save file for the measurement of Equivalent Widths in a high-resolution spectrum. It was written by Wonseok Kang and Sang-Gak Lee (Seoul National University). Version 1.1 was last modified in January 2013.
TARA ( Tools for ACIS Real-time Analysis)
TARA is an IDL widget which was originally developed at Penn State University for for the pre-launch calibration of the AXAF CCD Imaging Spectrometer (ACIS), now aboard the Chandra X-ray observatory, but which is generally useful for studying event data. The HETG Analysis Kit (HAK) software is available for analyzing data from the High-Energy Transmission Grating (HETG) aboard Chandra. Joel Kastner and his students at the Rochester Institute of Technology make available IDL software for Subpixel Event Repositioning for the ACIS detectors.
Time Utilities
Jason Eastman (OSU) and colleagues make available well-documented IDL code for precision conversion to and from barycentric Julian date.
Ultraviolet Imaging Telescope (UIT) software
The UIT image display software was a precursor to the IDL Astronomy Library, but has some additional routines for image display and astrometry. Last updated in 1995 so it is pretty obsolete.
Ultraviolet Spectral Analysis Software
Some of the ultraviolet spectral analysis software (e.g. multiple Gaussian fits) might be useful for analysis on other types of spectral data. The IUE (International Ultraviolet Explorer) Data Analysis Center is probably the oldest IDL-based astronomical data analysis package (last updated June 1999). The FUSE (Far Ultraviolet Spectrographic Explorer) IDL software includes some excellent general useful tools for the analysis of 1-d spectra (last updated February 2007). Stephen McCandliss (Johns Hopkins U.) has written H2TOOLS for the analysis of molecular hydrogen spectra. The Galex Explorer (GALEX) mission includes grisms to obtain ultraviolet spectra, and Todd Small (Cal Tech) has developed GALEXSpec, an IDL widget for assessing the spectra in a GALEX field. Charles Danforth (U. of Colorado) makes available IDL tools for analyzing data from the Cosmic Origins Spectrograph (COS) (last updated June 2014).
ULySS (University of Lyon Spectroscopic analysis Software)
ULySS is a well-documented package developed at the Observatoire de Lyon to fit a spectrum with a linear combination of non-linear components convolved with a line-of-sight velocity distribution (LOSVD) and multiplied by a polynomial continuum. It is used to study stellar populations of galaxies and star clusters and atmospheric parameters of stars. Version 1.2 was released in November 2012.
Universal Transit Modeler (UTM) software
Hans-J�rg Deeg (Instituto de Astrof�sica de Canarias) has developed the UTM software, which is light-curve simulator for transiting or eclipsing configurations. He also makes available the vaphot software, a differential photometry package for IRAF and IDL.
Fred Walter's IDL Software
This site at the State University of New York (SUNY) at Stonybrook includes the ICUR package developed by Fred Walter & Jim Neff for the analysis of 1-d astronomical spectra, and a package for the photometric reduction of Kitt Peak near-infrared images.
ZODIPIC Software
The ZODIPIC package is an IDL program written by Marc Kuchner (NASA/Goddard) for synthesizing images of exozodiacal clouds. It also has enough tweakable parameters to serve as a general-purpose modeling tool for optically-thin disks. Zodipic Version 2.1 includes dust with real optical constants, and user-specified dust maps. Christopher Stark (Goddard Space Flight Center) distributes DUSTMAP, an IDL and C package to view debris disks from any vantage point -- even from within! Version 3.1.2 was released in April 2015.
IDL Astronomy Library Home Page

General Astronomy Sites

FITS Support Office
The main source for information about the Flexible Image Transport System (FITS) data format, which is widely used in astronomy.

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Last Updated: 25-Sep-2022