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3 Packages

 3.1 General Purpose
 3.2 Pipeline systems
 3.3 Image Processing & Photometry
 3.4 Spectroscopy
 3.5 Time Series & Polarimetry
 3.6 Database Management
 3.7 Specific Wavelengths
 3.8 Specific Instruments
 3.9 Format Conversion
 3.10 Mathematics & Statistics
 3.11 Graphics

Starlink aims to provide maintainable, portable, and extensible applications packages that work in harmony by sharing a common infrastructure toolkit, standards, conventions, and above all, a standard data format. Individual packages are no longer required to perform all functions, so they are easier to change and are more adaptable to outside developments. New functions and user interfaces can be added as required. A recent example of this flexibility is the introduction of the ability to access ‘foreign data formats’ from all Starlink packages, because they use a common infrastructure library.

Applications are unified by sharing the same basic data structure – the NDF (extensible n-dimensional data format). This contains an n-dimensional data array that can store most astronomical data, such as spectra, images, and spectral-line data cubes. The NDF may also contain information like a title, axis labels and units, error, and quality arrays. There are also places in the NDF, called extensions, to store any ancillary data associated with the data array, even other NDFs.

3.1 General Purpose


AIPS
— Image processing Not distributed
IDL
— Interactive data language Not distributed
IRAF
— Image reduction and analysis facility
MIDAS
— Munich image data analysis Not distributed
XANADU
— GSFC software system
STARJAVA
— Starlink Java Infrastructure and Applications Set


AIPS SUN/207 MUD/101

Calibrate and edit radio-interferometric data, construct images using Fourier synthesis techniques and display and analyse these images.

The Astronomical Image Processing System (AIPS) is in widespread use by radioastronomers. It has a richer set of general image processing functions than any other astronomical software package.

It can:

IDL MUD/29,30,31,161

Explore and manipulate data using a comprehensive set of tools.

The Interactive Data Language (IDL) is proprietary package, written by Dave Stern of Research Systems Inc, Denver, It is only available on some Starlink nodes. At its simplest level it can be used as a very powerful arithmetic and graphics utility for processing data arrays.

It provides:

It can be used with minimal effort for many applications, or developed into more complex procedures as required.

IRAF SUN/179.MUD/104,105,154,156,157

Reduce and analyse data – general purpose.

The Image Reduction and Analysis Facility (IRAF) was developed by the National Optical Astronomical Observatory (Kitt Peak), and has been adopted by the Space Telescope Science Institute in Baltimore as the principal data analysis environment for Hubble Space Telescope (HST) data. (This data can also be reduced by KAPPA and FIGARO.) It contains general image processing and graphics applications, plus programs for reducing and analysing optical astronomical data. It is as portable and device independent as possible; for example, it includes its own programming language. Although it runs on a variety of computers, in practice it usually runs best on one particular type (Suns at present).

It is a very large system which is supported by extensive documentation. Every Starlink node should have a copy of the User Handbook.

IRAF is one of several major software environments which are available to Starlink users and upon which entire data-analysis campaigns can be based. Other examples include AIPS, IDL, and MIDAS, as well as Starlink’s own large collection of infrastructure tools and application packages, and the various forms of the FIGARO system. Each has its own particular strengths and special capabilities; IRAF and AIPS are the most comprehensive overall.

The excellent support provided by IRAF’s home institute (with which Starlink maintains close contact) means that comparatively little national UK Starlink support is called for and provided; the same is true for the other overseas environments mentioned above.

IRAF is a sound choice for many Starlink users doing data analysis, especially where compatibility with overseas collaborators is a requirement. The choice is harder for those wishing to develop major applications of their own, who may be reluctant to adopt IRAF’s non-industry-standard SPP programming language, or who feel uncomfortable with the limitations of the ‘flat’ IRAF data formats. Those who need formal guarantees of future support should also be very wary about committing themselves to any package which is not under UK control. However, IRAF is an important weapon in the armoury of the average Starlink data-analysis user, and likely to remain so for some years.

An important part of Starlink’s present software plans is to enhance ‘interoperability’ with other environments, IRAF being of special importance. Starlink applications can already share data with other packages via FITS files, but in the case of IRAF this data-interchange capability will be extended by enabling Starlink applications to read and write IRAF data files. This will mean that a user can run IRAF in one window on their screen and a Starlink package (e.g. CCDPACK) in another, processing the same datasets with each. A further capability, currently being investigated, would be to run Starlink applications from the IRAF command-line just as if they were native IRAF applications.

MIDAS

Reduce and analyse optical astronomy data within a basic image processing environment.

The Munich Image Data Analysis System (MIDAS) was developed by the Image Processing Group of the European Southern Observatory (ESO). It consists of a monitor which controls the execution of individual tasks, and a large set of image processing applications. Since the results of reducing astronomical images are usually numbers (not other images), a comprehensive and flexible table system forms an essential part of the system. New applications can be added easily, even by non-professional programmers.

Its main features are:

It also contains extensive packages in the areas of spectral reduction (including data in long slit and échelle formats), CCD observations, crowded field photometry, object search and classification, fitting and modeling of data, astrometry, and statistical analysis.

STARJAVA SUN/251

Starlink is developing a set of Java data reduction and analysis tools and Java data access classes. The new Java tools and classes are needed to produce applications in the Virtual Observatory (VO) era, and to complement the AstroGrid and other VO capabilities such as the International Virtual Observatory Alliance Data Model.

You can view a section of a proposed International Virtual Observatory Alliance Data Model, including HDX, NDX and Table data structures with the WCS astrometry library at:

http://www.starlink.ac.uk/java/java.htm

The Starlink Java Software (STARJAVA) has had numerous changes and additions. STARJAVA can now be considered as a separate entity from the classic Starlink applications and libraries, although in this release it is provided as a standard Starlink package.

The document (SUN/251) Getting Started with the Starlink Java Infrastructure and Applications Set describes the package and
/star/starjava/javadocs/index.html
describes the Starlink STARJAVA classes API. There are miscellaneous documents in
/star/starjava/docs/
for individula package information and third party application documentation.

The STARJAVA package contains the following applications and classes. Note, SPLAT, TREEVIEW, JNIAST and JNIHDS have been moved to the STARJAVA package, instead of being individual packages.

APPLICATIONS/UTILITIES:

FROG - Display and analysis of time series data.

SOG - Son of GAIA.

SPLAT - Spectral Analysis Tool.

TABLECOPY - Copy tables from one format to another.

TOPCAT - Tool for OPerations on Catalogues and Tables.

TREEVIEW - Hierarchical data viewer.

CLASS LIBRARIES:

ARRAY - N-dimensional array manipulation and I/O.

ASTGUI - AST specific UI components.

AXIS - Third generation Apache SOAP.

COCO - Java UI for Coco.

DOM4J - Third party DOM access library (org.dom4j.*).

FITS - STARJAVA-specific FITS access.

HDS - Non-native HDS utility classes.

HDX - A flexible, extensible, data model for astronomical images, tables and other metadata.

JAIUTIL - Utility classes for JAI.

JETTY - HTTP Server and Servlet Container.

JNIAST - Java Native interface to AST.

JNIHDS - Java Native Interface to HDS.

JSKY - Java Components for Astronomy.

JUNIT - Third party unit testing framework (junit.*).

NDX - N-dimensional astronomical object manipulation and I/O.

PAL - Positional Astronomy Library.

RV - Java UI for RV.

TABLE - Generic table manipulation and I/O.

TAMFITS - Third party basic FITS access (nom.tam.*).

UTIL - Miscellaneous utillity classes.

VOTABLE - VOTable I/O.

The STARJAVA package can be considered to be independent of the standard USSC, and in future will be distributed separately. All the STARJAVA applications and classes are distributed under the GPL licence.

The SPLAT documentation (SUN/243)
SPLAT - A Spectral Analysis Tool
has been updated and can be found in
/star/starjava/docs/splat/sun243.htx/sun243.html.
It also appears in the DOCS package and can be seen with the command showme sun243.

STARJAVA is not available under Tru64 Unix.

XANADU

Analyse spectra, timing, and images of X-ray astronomical data obtained from multiple missions.

It was obtained from GSFC. Its home page is:

http://heasarc.gsfc.nasa.gov/docs/xanadu/xanadu.html.

Its principal components are:

XSPEC
Fit X-ray spectra – command-driven, interactive.

It is detector-independent, so it can be used for any spectrometer. It has been used to analyze data from HEAO-1 A2, Einstein Observatory, EXOSAT, Ginga, ROSAT, BBXRT, ASCA, CGRO, and IUE. It has also been used for simulations for XTE and AXAF.

XIMAGE
Display and analysis of multi-mission X-ray images.

It is instrument-independent and analyses data from any X-ray imaging detector, provided calibration files are available. It supports detailed analysis of EXOSAT CMA, Einstein HRI and IPC, ROSAT PSPC and HRI, and ASCA GIS and SIS data. It also supports some basic analysis of optical, infrared, and radio images. It has a built in data simulation program that can simulate images of current and future X-ray missions (e.g. SAX, AXAF, and XMM).

It can:

Its display and graphic capabilities are based on the PGPLOT graphics package, which supports most terminals and workstations. The saoimage package can also be spawned to display images and select regions.

While XIMAGE is a multimission package, it must first ‘know’ about the calibration information associated with a mission in order to be able to make a detailed image analysis. Some functions are mission-independent (e.g. display), but others are not (e.g. source detect). It will read images from an unknown mission, but beware of trying to make a detailed analysis – adding new missions usually requires either adding new files and/or adding new calls and relinking XIMAGE.

XRONOS
Analyse timing – general purpose.

Although designed mostly for X-ray astronomy, it is basically detector and wavelength-independent. It has been used to analyse data from the Einstein Observatory, EXOSAT, and Ginga, as well as optical photometry and helioseismology data. It includes programs for:

It consists of a collection of programs, each dedicated to one task, which can be run from the control environment provided by the XRONOS program. This is characterised by three different user interfaces: ‘question/answer’, ‘partial question/answer’, and ‘command driven.’ Command files are supported by the last two. Its applications can be run in command-driven fashion within the EXOSAT Database System.

XANADU also contains native versions of:

Of these, PGPLOT and FITSIO are also distributed independently by Starlink.

3.2 Pipeline systems


ORAC-DR
— UKIRT and JCMT instrument data reduction pipeline


ORAC-DR SUN/230,SUN/231,SUN/232, SUN/246

General purpose data reduction pipeline

ORAC-DR is the data reduction component of the ORAC system used for telescope and instrument control at the United Kingdom Infrared Telescope (UKIRT) and the James Clerk Maxwell Telescope (JCMT) on Hawaii. It provides a general purpose automatic data reduction pipeline for the CGS4, UFTI and IRCAM instruments on UKIRT and the SCUBA instrument on JCMT.

ORAC-DR recipes to drive the reduction of a set of observations made to a known observation pattern at the telescopes. The headers data of each dataset is read to discover which data processing recipe to apply to it. The data reduction is performed by tasks from other Starlink packages such as KAPPA, CCDPACK, SURF, POLPACK and PHOTOM. It can also use GAIA for image display.

3.3 Image Processing & Photometry


ATOOLS
— Coodinate frame manipulation
CCDPACK
— CCD data reduction
DAOPHOT
— Stellar photometry
ESP
— Extended surface photometry
EXTRACTOR
— Automatic detection of objects on an astronomical image
GAIA
— Graphical image analysis
KAPPA
— Image processing & visualisation
KAPRH
— Retired KAPPA tasks
PHOTOM
— Aperture photometry
PISA
— Position, intensity, and shape analysis
SAOIMAGE
— Astronomical image display
STARMAN
— Stellar photometry
SX
— Data visualisation


ATOOLS

Manipulation of coordinate frame descriptions.

ATOOLS is a new package of applications which manipulate descriptions of coordinate frames, mappings, etc., in the form of AST Objects. Each application within the ATOOLS package corresponds closely to one of the functions within the AST library. ATOOLS thus provides a high-level interface to the AST library.

CCDPACK SUN/139

Reduce CCD-like data, and mosaic frames together.

You can debias, remove dark current, pre-flash, flatfield, register, resample, and normalize your data.

Perhaps the most important and useful feature of the package is its ability to handle large numbers of data files automatically, so that repetitive reduction procedures can be handled in a straightforward and efficient way. This uses a scheduling system that only requires knowledge of the frame types (bias, flatfield, etc.) and important CCD geometric features. Using this information, it can decide how to reduce your data and may then run the necessary programs. The frame types and detector characteristics can be obtained from FITS headers, for certain telescopes/CCDs, so your job could be reduced to identifying the telescope/detector used and the frames you want reducing.

The automated reduction system can be controlled from an X-based GUI that has been specifically designed to help novice and/or occasional users of CCD data (although it is expected to appeal to the more experienced as well). Ease-of-use is achieved by limiting the options to those of immediate concern by providing a selection of known detectors and by having a context-sensitive help system. It also aims to be complete by allowing you to define the necessary geometric characteristics of your data interactively (if they cannot be obtained elsewhere). An equivalent command-line interface is also available.

Its core is a suite of programs to process large amounts of data. Consequently, all the routines process lists of data, and also record progress using a log system.

As well as performing the usual instrumental corrections, you can also remove defects and generate and propagate data errors. Debiassing can be performed using only the bias strips as well as using bias frames (combined to reduce noise levels). Calibration data can be combined using many different techniques (mean, median, trimmed mean, etc.), so you can pick a method that makes the most efficient use of your data.

Data registration is based primarily on the linear transformation (allowing offsets, scalings, rotation, and shear), although more general transformations can be used.

General linear transforms can easily be determined using an interactive procedure to display and select image features. Alternatively, if your datasets are just shifted with respect to each other, you may be able to register them by using a series of commands which locate all the objects in all the frames, determine the object-object correspondence, and then derive the transforms. A graphical application is also provided that allows you to select the objects to be used by identifying image pairs that overlap and have some objects in common.

Data resampling uses registering transforms which it stores inside your data, removing the need to remember them. They may also be applied to ‘rubber-sheet’ the data into novel configurations.

Normalisation and combination (often called mosaicing) is provided in a single comprehensive application, which is designed to deal with very large datasets. This uses robust methods to determine scale and/or zero-point corrections.

The CCDPACK package my be run from the IRAF CL.

DAOPHOT SUN/42 MUD/9,10

Stellar photometry of crowded fields.

It does the following tasks:

Profile-fitting in crowded regions is performed iteratively, which improves the accuracy of the photometry. It does not directly use an image display (which aids portability), although three additional routines allow results to be displayed on an image device. It uses image data in NDF format, which means it is interoperable with other Starlink packages.

ESP SUN/180

Photometry of galaxies and other extended objects.

It can:

It processes images in NDF format, so you can use it in conjunction with packages like KAPPA, CCDPACK, FIGARO, PHOTOM, JCMTDR, and PISA. You can define areas to exclude or include in the analysis, using keyword descriptions in text files.

Extractor SUN/226

Locate and parameterize objects in a 2-d image.

EXTRACTOR is a program for automatically detecting objects on an astronomical image and building a catalogue of their properties. It is particularly suited for the reduction of large scale galaxy-survey data, but also performs well on other astronomical images.

EXTRACTOR is a development of Emmanuel Bertin’s SExtractor (Source-Extractor) program repackaged for use in the Starlink Software Environment. This means that it uses the Starlink parameter system, accepts images in NDF format and uses the AST library for astrometry.

GAIA SUN/214

A traditional image display tool (like SAOIMAGE), but which can integrate other programs.

It is derived from the RTD (Real Time Display) tool, developed as part of the VLT project at ESO. RTD is free software under the terms of the GNU copyright.

The current version is a preliminary release which is intended to assess the impact of GAIA/RTD’s enhancements for performing highly interactive graphical image analysis. It provides the following functions:

The GAIA package may be run from the IRAF CL.

KAPPA SUN/95

General-purpose functions, particularly suitable for image processing, data visualisation, and manipulating NDF components.

KAPPA is the backbone of Starlink’s application packages. Its facilities integrate with the more specialised Starlink packages described in this survey. Thus, the functionality of KAPPA should not be regarded in isolation.

It can process data in formats other than NDF, such as FITS and IRAF, by using an ‘on-the-fly’ conversion scheme. Many commands can process data arrays of arbitrary dimension, and others work on both spectra and images. It operates from both the Unix C-shell, and the ICL command language.

KAPPA should not be perceived as a rival to FIGARO. Now that FIGARO is integrated with other Starlink packages, they should be seen as complementary, with FIGARO concentrating on spectroscopy and KAPPA on image processing.

In a wider context, KAPPA offers facilities which are not in IRAF, for instance: handling data errors, quality masking, a graphics database, availability from the shell, as well as more n-dimensional applications, widespread use of data axes, and a different style. It also integrates with instrument packages developed at UK observatories.

With the automatic data format conversion, and the likelihood that KAPPA and other Starlink packages will be available from within the IRAF command language, you should be able to pick the best or relevant tools from both systems to get the job done.

Currently, about 180 commands are available from both the Unix C-shell and from the ICL command language. They provide the following facilities:

There are also many applications for data visualisation:

KAPPA handles bad pixels, and processes quality, variance, and other information stored within NDFs. In order to achieve generality, it does not process non-standard extensions; however, it does not lose non-standard ancillary data since it copies extensions to any NDFs that it creates.

Although oriented towards image processing, many commands will work on NDFs of arbitrary dimension, and others operate on both spectra and images. Many applications handle all non-complex data types directly, for efficient memory and disk usage. Those that do not will usually undergo automatic data conversion to produce the desired result.

Its graphics are device independent. X-windows and overlays are supported.

The KAPPA package may also be run from the IRAF CL.

KAPRPH SUN/239

Retired KAPPA commands

KAPRH is a package containing commands retired from the KAPPA package (see SUN/95). These commands have been removed from KAPPA but are retained in KAPRH to satisfy any occasional need there may be for them. KAPRH is documented in SUN/239.

KAPRH contains the following retired KAPPA commands:

CONTOVER, GREYPLOT, INSPECT, MOSAIC, QUILT, SNAPSHOT, TURBOCONT

as well as a help command: KRHHELP.

PHOTOM SUN/45

Aperture photometry.

It has two basic operating modes:

The aperture is circular or elliptical, and the size and shape can be varied interactively on the display, or by entering values from the keyboard or parameter system. The background sky level can be sampled interactively by manually positioning the aperture, or automatically from an annulus surrounding the object.

It is used by the Graphical Astronomy and Image Analysis tool (GAIA) which integrates the tasks of aperture photometry with an image display tool. This allows the detailed inspection of objects and their environments, and provides a highly interactive environment for placing, rotating, and resizing apertures.

PISA SUN/109

Locate and parameterize objects in a 2-d image.

The Position, Intensity, and Shape Analysis package (PISA) is applicable in most areas of astronomy where direct imaging is required. It is particularly intended for faint object detection and can do this automatically, based on software used with the APM automatic plate measuring machine.

Its core is a routine which performs image analysis on a 2-d data frame. It searches for objects having a minimum number of connected pixels above a given threshold, and extracts the image parameters (position, intensity, shape) for each object. The parameters can be determined using thresholding techniques, or an analytical stellar profile can be used to fit the objects. In crowded regions it can deblend overlapping sources.

SAOIMAGE SUN/166. MUD/140

Display astronomical images.

You can manipulate images in a number of ways, see the changes applied, and when you are happy with the result, print it on a Postscript printer. It uses X-window hardware.

It can:

Other features:

STARMAN SUN/141

Stellar photometry.

STARMAN is not distributed on Starlink CDs and has not been ported to Linux. It is optionally available at UK Starlink sites.

Starman’s many image and table handling programs have other uses, but its main applications are:

The package is a coherent whole, for use in the entire process of stellar photometry from raw images to the final standard-system magnitudes and their plotting as colour-magnitude and colour-colour diagrams. Its functions are:

SX SC/2, SG/8, SUN/203

Enhancements to DX.

DX (Data Explorer) is a scientific data visualisation and analysis package marketed by IBM. It can visualise and display many sorts of astronomical data. It employs a data-flow driven client-server execution model, and provides a comprehensive range of data manipulation, visualisation, and display functions. Visualisations can be generated using a visual programming editor or a text-based scripting language.

Starlink recommends DX for displaying 3-d scalar and vector data. However, it is not available at all Starlink sites – ask you Site Manager.

The SX enhancements have a number of purposes. They:

3.4 Spectroscopy


DATACUBE
— IFU datacube analysis
DIPSO
— Spectrum analysis and plotting
ECHOMOP
— Échelle data reduction
FIGARO
— General data reduction
NDPROGS
n-dimensional data analysis


DATACUBE SUN/237, SC/16

IFS datacube manipulation and visualisation.

DATACUBE is a new package which provides a set of tools for manipulating and visualising IFS (Integral Field Spectrograph) datacubes. Also known as an IFU (Integral Field Unit), the IFS is relatively new in astronomical instrumentation and is therefore rapidly developing. The DATACUBE package has been implemented mainly as a series of scripts which drive existing Starlink packages to manipulate IFU data. This approach allows changes to be made to tasks quickly as data analysis requirements evolve. There are also a small number of IFU-specific tasks implemented in Fortran.

IFU data analysis is discussed in detail in the cookbook The IFU Data Product Cookbook(SC/16).

DIPSO SUN/50

Analyse and visualise spectroscopic data.

A powerful and versatile package, specifically tailored to the requirements of modern astronomical research.

It can access a large number of spectra simultaneously. This lets you perform the same operations repeatedly on successive spectra, either manually or using scripts, ensuring uniformity in the data (especially important for time-series spectroscopy). It can plot spectroscopic data rapidly and conveniently, and combines analysis and high-quality graphical output in a simple command-line driven environment.

It began as a simple plotting package incorporating some basic astronomical applications. Indeed, if you just want to read in some data, plot them, and measure some equivalent widths or fluxes, you can do this easily. To make more complicated things possible, a number of extra functions and parameters are provided. A macro facility allows convenient execution of regularly used sequences of commands, and a simple Fortran interface permits ‘personal’ software to be integrated with the program. User programs can be added to the system and defined as new commands.

The following operations are available:

ECHOMOP SUN/152

Reduce échelle spectra data frames.

Options range from full-scale automated reduction to step-by-step order-by-order manually assisted processing. It was written originally to reduce data from the University College London Échelle Spectrograph (UCLES), but the algorithms are sufficiently flexible to reduce spectra from many sources.

It can:

FIGARO SUN/86.MUD/12,13,14

Reduce and analyse astronomical data.

FIGARO is a general-purpose data reduction package. It contains particularly extensive facilities for reducing spectroscopic data, but also has powerful facilities for manipulating direct images and data cubes. Starlink recommends it as the most complete spectroscopic data reduction system in the Collection.

It can be used interoperably with other packages, most notably KAPPA, because it supports the NDF data format, and therefore all foreign formats for which conversion utilities exist. These include its old DST format, FITS, and IRAF. The use of NDF also means that you can automatically record data processing history, and can operate on sub-sets of spectra and images. Another feature is the propagation of error/data-quality arrays through the data reduction calculations.

It can:

The programs from the old SPECDRE and TWODSPEC packages have been merged with FIGARO and provide additional facilities:

The topics addressed by the applications are mainly:

The FIGARO programs may be run from the IRAF CL but the former SPECDRE and TWODSPEC programs are not yet available under the IRAF CL.

NDPROGS SUN/19

Manipulate and display images of up to six dimensions.

The NDPROGS package is no longer supported and will be withdrawn if operating system or compiler changes cause it to fail. It is not distributed on Starlink CDs but may be installed at UK Starlink sites as a legacy package.

Primarily, it is designed to manipulate Taurus spectral line data cubes, which are 3-d images in which two of the dimensions are spatial and the third is spectral. However, it contains no instrument-specific features, and can therefore be used to analyse similar data.

The term ‘image’ here simply means a regular data array, which might be anything from a 1-d spectrum or profile to a 4-d array consisting of several long-slit spectra with polarization vectors. The upper limit of six dimensions is imposed by the software which interfaces with HDS and has no other significance.

The package can read FIGARO images, and images written by NDPROGS can be read by any FIGARO program which can handle the number of dimensions involved. It duplicates the functions of standard FIGARO programs as far as 1-d, 2-d, and 3-d images are concerned, but with new features. It will also accept NDF format files. Most NDPROGS routines now handle data quality and error arrays, thus widening the scope and accessibility of the package.

3.5 Time Series & Polarimetry


PERIOD
— Time series analysis
POLMAP
— Linear spectropolarimetry
POLPACK
— Dual beam imaging polarimetry
TSP
— Time series & polarimetry


PERIOD SUN/167. SSN/25

Search for periodicities in data.

It is menu-driven. You can:

Read and write data
Examine data
Manipulate data

Many sophisticated techniques are used to search data for periodicities; data points do not have to be equally spaced. You don’t need in-depth knowledge of the methods employed in order to use them. They can be treated as black-boxes. These include:

Significance estimates for periods derived by most methods are notoriously unreliable. In PERIOD, the Fisher randomisation method, one of the best, is employed.

POLMAP SUN/204

Analyse linear spectropolarimetry data.

A linear polarization spectrum is a set of Stokes vectors (Iλ,Qλ,Uλ). Hence, linear spectropolarimetric data is 4-d (6-d if the variance arrays of the Stokes parameters are included) and cannot be manipulated using standard spectral analysis packages such as DIPSO.

Its user interface is similar to DIPSO’s, but doesn’t provide its wealth of spectral analysis routines. It is designed specifically for the spectropolarimetrist. The manual includes a simple step-by-step guide to the program, and some example data analysis recipes.

It is complimentary to TSP (like FIGARO is to DIPSO). TSP runs under the Starlink software environment and can handle time-series and polarimetric data. It is biased towards data reduction and can handle several different instruments. POLMAP, on the other hand, does no data reduction, but was designed with data analysis in mind. POLMAP can also display data that TSP cannot handle, and can read and write TSP polarization spectrum format files.

POLPACK SUN/223

Imaging Polarimetry data reduction

POLPACK is a package of applications for mapping the linear or circular polarization of extended astronomical objects. Data from both single and dual beam polarimeters can be processed.

POLPACK processes data in NDF format. Other astronomical data formats may also be processed using transparent on-the-fly data conversion facilities provided by the NDF subroutine library, and the CONVERT package.

The facilities provided by POLPACK include:

POLPACK does not provide facilities for performing instrumental corrections such as flat-fielding, de-biassing, etc. Such corrections should be applied to the data before using POLPACK, so that POLPACK can assume that pixel values are proportional to the combined intensity of sky and object. Corrections can be made, however, to take account of any differences in the exposure times between raw frames, and any difference in the sensitivity of the two channels of a dual-beam polarimeter. These corrections rely on redundancy in the supplied data, and require a specific set of analyser positions to be used.

TSP SUN/66

Reduce time-series and polarimetric data.

Time-series and polarimetry facilities are missing from most existing data reduction packages, which are usually oriented towards either spectroscopy or image processing, or both. TSP, however, can process the following data:

3.6 Database Management


CATPAC
— Catalogue and table manipulation
CURSA
— Catalogue and table manipulation


CATPAC SUN/120

Manipulate catalogues and tables.

CATPAC is no longer supported and is not distributed on Starlink CDs. CATPAC may remain as a legacy package at UK Starlink sites.

It can input, process, and report tabular data, including astronomical catalogues. In particular, it can:

CATPAC was designed as a replacement for SCA but is being superseded by CURSA (see below).

CURSA SUN/190

Manipulate catalogues and tables.

It can:

Subsets can be extracted from a catalogue in a format suitable for plotting by other Starlink packages such as PONGO. It can access catalogues held in the following formats:

Catalogues in the STL format are simple Ascii text files.

3.7 Specific Wavelengths


ASTERIX
— X-ray data processing
SPECX
— Millimetre-wave spectral reduction


ASTERIX SUN/98. MUD/4

Analyse astronomical data in the X-ray waveband.

ASTERIX has been withdrawn from the Starlink Software distribution and is no longer included on Starlink CDs (from Spring 2000) due to the end of funding for the ROSAT satellite program. It may remain as a legacy package at UK Starlink sites.

Continued ‘best efforts’ support may be provided by the Space Research group at the University of Birmingham for the recent development version. This may be found on the Asterix Home Page (see http://www.sr.bham.ac.uk/asterix/). No support will be provided for the Starlink version.

Many of its programs are general purpose and are capable of analysing any data in the correct format. It is instrument-independent, and currently has interfaces to the EXOSAT and ROSAT instruments.

Its data are stored in HDS files, and are therefore compatible with many other Starlink packages. There are basically two different types:

Binned data
– (e.g. time series, spectra, images) are stored in NDF format. Data errors (stored in the form of variances) and quality are catered for.
Event data
– store information about a set of photon ‘events’. Each event will have a set of properties, e.g. X-position, Y-position, time, raw pulse height.

The input data are first processed by an instrument interface. Event data are then processed and binned, and the binned data are processed. Finally, graphical output is generated.

The commands may be classified as follows:

SPECX SUN/17. MUD/69,70

Reduce and display mm and sub-mm data.

Although it can process spectra from many different instruments, it is particularly applicable to JCMT data. It can:

It uses its own data format, so it is not possible to access directly reduced spectra from other packages. However, it can import data from GSD-format data files, as produced by the JCMT; write out maps and spectra in the file formats of FIGARO and KAPPA; and write spectra and maps to Ascii files for input into other packages.

3.8 Specific Instruments


CGS4DR
— CGS4 (UKIRT) data reduction
FLUXES
— JCMT flux density calibration
IRAS90
— IRAS data reduction
IRCAMDR
— IRCAM (UKIRT) data reduction
IRCAMPACK
— IRCAM (UKIRT) data reduction
IUEDR
— IUE data reduction
JCMTDR
— JCMT (UKT14) data reduction
REPACK
— ROSAT (WFC) data reduction
SURF
— SCUBA data reduction
WFCPACK
— ROSAT (WFC) data reduction
XRT
— XRT data tools


CGS4DR SUN/27

Reduce CGS4 data.

Cgs4dr is not available on Linux.

The fourth generation cooled grating spectrometer, CGS4, operates on UKIRT in the 1–5 μm region at resolutions in the range λ/Δλ 300–20000. To reduce background noise, it is maintained on the telescope in vacuum at cryogenic temperatures. It achieved first light at UKIRT on 4 February 1991. On 22 April 1995 a new InSb 256 × 256 array was commissioned. The new array is much more sensitive than previous detectors, and on a good night you can acquire and reduce 100 Mb of high quality data.

CGS4DR was designed and tested within the FIGARO and ADAM environments. The output data is readable by standard FIGARO applications, although not all may handle the quality and error arrays correctly.

It can reduce spectrographic data automatically. No system, however, will do everything you want, so some post-processing may be needed. The aim is to produce publishable quality spectra at the telescope via an automated reduction paradigm.

It can:

FLUXES SUN/213

Calculate accurate topocentric positions of the planets, and also integrated flux densities of five of them at a number of wavelengths, for the JCMT telescope on Mauna Kea, Hawaii.

It provides calibration information at the effective frequencies and beam-sizes employed by the UKT14 and SCUBA receivers on this telescope.

The filter centre and widths are shown for each wavelength used. The filter frequencies are the effective frequencies for 1mm of water vapour.

The calculated planet positions should normally be accurate to better than 1 of arc. The value for the Moon is less accurate than this, and for critical applications requiring sub arc-second accuracy you should use a different method.

The version distributed by Starlink has been modified to employ the highly accurate JPL ephemeris in all planetary position calculations. It also adopts the Starlink parameter interface, and a more robust file reading system.

A script, FLUXNOW, runs the program for the current time and date. This gives you current positions and flux levels for all the planets.

IRAS90 SUN/82, 161, 163, 165

Process IRAS data.

IRAS90 is not distributed on Starlink CDs and is no longer supported though it may remain as a legacy package on UK Starlink sites. There is no Linux port.

The Infrared Astronomical Satellite (IRAS) flew in 1983. It carried three instruments: a main detector array, a low resolution spectrometer (LRS), and a chopped photometric channel (CPC). Most of the observations were part of a whole sky survey, but some pointed observations of specific objects were made. Raw data was calibrated and cleaned up to produce a data set called the Calibrated Reconstructed Detector Data (CRDD). This was the source of the final data products, which include catalogues and images.

Several items of Starlink software can be used to process and examine IRAS data. Use KAPPA to process and display images, DIPSO to analyse LRS spectra, CURSA to access and report on the catalogues. However, the most closely related software is IRAS90. This can process CRDD data to produce an image of a region of the sky, or search for and examine an object at a given position.

IRCAMDR SUN/41

Reduce, analyse, and display data from IRCAM3. It can also handle any 2-d image in the standard Starlink NDF data format.

IRCAMDR is not distributed on Starlink CDs and there is little or no support. There is no Linux port. IRCAMDR may remain as a legacy package at UK Starlink sites. Reduction of IRCAM data is now best performed using the ORAC-DR data reduction facility.

IRCAM3 is a camera on the United Kingdom Infra-red Telescope (UKIRT). In addition to handling IRCAM3 images of 256×256 pixel size, it can handle IRCAM1 and IRCAM2 images of 62×58 pixels. Almost all the applications (with the exception of med3d) will work on NDF images of any physical (pixel) dimensions, for example, 1024×1024 CCD images can be processed (med3d median-filters stacks of images up to 256×256 in size at present).

It can:

IRCAMPACK SUN/177

Process IRCAM data.

IRCAM is an infrared camera on the United Kingdom Infra-red Telescope (UKIRT).

CCDPACK and KAPPA will probably do most of the processing you require. IRCAMPACK provides extra facilities. It can:

IUEDR SG/3, 7. SUN/37. MUD/45, 46,47

Process data from the IUE échelle spectrograph, starting with the raw image and finishing with the fully calibrated spectrum.

The International Ultraviolet Explore (IUE) is an ultraviolet telescope in geosynchronous orbit.

It can:

JCMTDR SC/1. SUN/132

Reduce continuum mapping data obtained with the UKT14 instrument on the JCMT.

JCMTDR is now distributed on Starlink CDs. There is now a Linux port.

The James Clerk Maxwell Telescope (JCMT) at Mauna Kea Observatory observes in the millimetre-wave part of the spectrum.

The program can:

Data files can be read in either ‘old FIGARO’ or NDF formats; NDF is recommended as this allows other Starlink packages to process the data. IRCAMPACK can also access the main data arrays, although other parts of the data structure will be inaccessible.

REPACK SUN/208

Handle ROSAT Wide Field Camera survey data.

REPACK is not distributed on Starlink CDs though it may remain as a legacy package at UK Starlink sites. There is no linux Port. With the demise of the ROSAT satellite there is no support for REPACK.

During the period from July 1990 to January 1991, the ROSAT Wide Field Camera (WFC) performed the first ‘all sky survey’ at extreme-ultraviolet (EUV) wavelengths. The whole sky, or 96% of it, was imaged in two passbands, S1 and S2, covering the ranges 60–140Å and 110–200Å respectively. An initial bright source catalogue (BSC) of 383 sources was produced by Pounds et.al. A new list, the 2RE Catalogue of 479 sources, has recently been published. The survey data (images and ‘raw’ photon event files) are now in the public domain. REPACK fully exploits this data.

The data is available through the Leicester Data Archive Service (LEDAS). Images were sorted from the event files and screened for ‘high background’ and ‘moon in WFC field-of-view’ and named after the ecliptic latitude and longitude of the region of sky that they covered. They are 2.7×2.7 in extent with a resolution of 1×1 arcmin2 per pixel. The photon event files are overlaid on a similar ecliptic grid system. Some 13,000 image pairs and 13,000 event files were produced by this scheme, covering almost the whole sky.

Images can be retrieved in various formats: HDS, FITS, and GIF. REPACK only operates on HDS format images. Event files, available just in FITS format, can be sorted to ASTERIX (HDS) datasets such as images and light-curves.

SURF SC/10, 11.SUN/216

SCUBA data re-reduction facility

SURF is a set of programs for reducing demodulated Submillimetre Common-User Bolometer Array (aka SCUBA) data obtained from the James Clerk Maxwell Telescope.

The facilities provided by SURF include:

WFCPACK SUN/62

Produce ASTERIX (HDS) datasets from Wide Field Camera data collected during the pointed phase of the ROSAT mission.

WFCPACK is not distributed on Starlink CDs though it may remain as a legacy package at UK Starlink sites. There is no linux Port. With the demise of the ROSAT satellite there is no support for WFCPACK.

A sort program generates datasets such as time series and images from pre-processed event data supplied as part of the ROSAT WFC Observation Datasets (RWODs). An exposure program corrects them allowing for instrument characteristics. In addition, a simple database manager allows an index of RWODs to be maintained and searched. The programs make use of the ADAM/ICL environment, and a number of ICL procedures are provided to perform some of the more commonly required operations, such as extracting background subtracted lightcurves.

XRT

ROSAT XRT data access.

The XRT is a package provides access to ROSAT XRT data stored in FITS files for analysis by other Starlink Packages. The tools are based on the ASTERIX ROSAT XRT toolset from version 2.3-b1, but do not include the ASTERIX analysis tools.

At present the documentation and Help facilities are copies of the ASTERIX files, so that some of the tools used in examples may be no longer available.

3.9 Format Conversion


CONVERT
— Data format conversion


CONVERT SUN/55

Convert the standard Starlink n-d data format NDF to and from other formats.

A major advantage of this package is that it deals sensibly (as far as possible) with header information, which can be lost during translation by less robust software.

Currently, the Unix version can handle these formats:

The following formats can only be handled by the VMS version:

3.10 Mathematics & Statistics


ASURV
— Astronomical survival statistics
MAPLE
— Mathematical manipulation Not distributed


ASURV SUN/13. MUD/5,6

Analyse statistically astronomical data with upper limits.

Observational astronomers frequently encounter the situation where they observe a particular property of a previously defined sample of objects, but fail to detect them all. The data then contains ‘upper limits’ as well as detections, preventing the use of simple and familiar statistical techniques in the analysis. However, a variety of other statistical methods exist to deal with these problems which are collectively called ‘survival analysis’ or the ‘analysis of lifetime data’ from their origin in actuarial and related fields. The upper limits are called ‘censored’ data points. ASURV is a menu-driven stand-alone computer package to help astronomers use some of these methods.

No statistical procedure can magically recover information that was never measured at the telescope. However, frequently there is important information implicit in the failure to detect some objects which can be partially recovered under reasonable assumptions. ASURV provides several two-sample tests, correlation tests, and linear regressions – each based on different models of where upper limits truly lie – so that you can judge the importance of the different assumptions.

MAPLE SUN/107. SGP/47. MUD/52,137-139,144,145

Interactive symbolic algebra computation.

It can perform hundreds of algebraic functions for use at all mathematical levels, and can provide solutions to many types of problem:

In addition, it can generate plots to illustrate graphically any function, including user-defined functions. You can also extend or redefine the numerous functions by writing MAPLE programs in the built-in Pascal-like language to create specialized functions.

More general information about computer algebra software is available in SGP/47.

It is marketed by WATCOM, Waterloo, Ontario, CANADA.

3.11 Graphics


MONGO
— Interactive data plotting Not distributed
PONGO
— Interactive data plotting
SM
— Interactive data plotting


MONGO SUN/64. MUD/54

Plot data interactively.

You can build up a complicated diagram, including graphics, text, axes, and so on, and then create publishable quality output. In general, it has been superseded by PONGO.

PONGO SUN/137

Plot data interactively.

It is like MONGO, but uses Starlink-PGPLOT as the plotting package. It is more powerful than MONGO and is Starlink-compliant, which means you can use it in conjunction with ICL and AGI. Features include:

The PONGO package may be run from the IRAF CL.

SM MUD/159,160

Draw graphs and plots interactively.

It has some image handling capability, but works mostly with vectors. It can: