IRSA Image Server - SIA v2 Queries

Available data-sets

Spitzer Heritage Archive (SHA)
Data-setCollection NameCalibration Level
Spitzer Heritage Archive
Public data taken before 02-Mar-2017
spitzer_sha 1, 2, and 3
WISE AllWISE Release
Data-setCollection NameCalibration Level
AllWISE Atlas Coadds wise_allwise 3
WISE AllSky Release
Data-setCollection NameCalibration Level
4-band Atlas Coadds wise_allsky 3
4-band Level 1B Frames wise_allsky 2
Cryo_3band Atlas Coadds wise_3bandcryo 3
Cryo_3band Level 1B Frames wise_3bandcryo 2
Postcryo (2-band) Level 1B Frames wise_2bandcryo 2
WISE Preliminary Release
Data-setCollection NameCalibration Level
Atlas Coadds wise_prelim 3
Level 1B Frames wise_prelim 2
Postcryo 2B wise_prelim_2bandcryo 2
WISE Merged Datasets
Data-setCollection NameCalibration Level
Level 1B Frames
Public data taken before 14-Dec-2014
neowiser 2
2MASS Datasets
Data-setCollection NameCalibration Level
2MASS All-Sky Data Release Images twomass_allsky 2
2MASS Full Survey Images twomass_full 2
2MASS 6X Catalog Images twomass_sixxcat 2
2MASS Full 6X Images twomass_sixxfull 2
2MASS Calibration Images twomass_calibration 2
2MASS 6-Degree Mosaics twomass_sixdeg 3


An overview of how to perform SIA v2 queries is provided below - for full details, please see the IVOA SIA v2 specification.

Metadata queries

To perform a metadata query, visit /SIA?MAXREC=0. The result will be a VOTable describing the image metadata columns that are returned by actual queries. All of IRSA's SIA v2 datasets have been regularized and are contained in the same table.

Query Constraints

An SIA v2 query returns a VOTable of images satisfying any number of constraints. By default, queries return results from all datasets. IRSA's SIA v2 holdings contain almost a billion records, so searches without constraints will time out. Common constraints are spatial (using the POS keyword), dataset (using the COLLECTION keyword), and/or calibration level (using the CALIB keyword) which we describe below. In addition, the type of output can be specified with the RESPONSEFORMAT keyword, and the number of rows can be limited with the MAXREC keyword. The complete list of parameters supported by IRSA's SIA v2 implementation is


The POS parameter value must consist of a shape described by ICRS coordinates in decimal degrees. It identifies the shape which returned images must intersect with.


  • POS=circle -164.7 -5.8 1
  • POS=polygon -164 -5 -165 -5 -165 -6 -164 -6
  • POS=range -105 -104 -22 -12

The spatial extent of an image is approximated by connecting its corners with great circles to form a spherical convex polygon. The search region as defined by this service is also a spherical convex polygon (or a point). Spatial predicate evaluation is performed on pairs of spherical convex polygons without recourse to any performance motivated short-cuts. Nevertheless, the implementation uses floating point arithmetic and results are therefore not guaranteed to be mathematically exact. Note also that the spatial extent of an image with a non-gnomonic projection (or large distortion terms) may not be well approximated by the technique employed. However, the images currently being served have gnomonic or orthographic projections, are of small area and have small distortion terms - hence, we believe our approximations are accurate enough to be useful.


The BAND parameter defines the wavelength interval(s) in meters to be searched for data. The value is an open or closed energy interval. The interval always includes the bounding values. A BAND constraint is satisfied if the interval intersects the wavelength coverage of the observation as returned in the em_min, em_max columns.


  • Find only J-band data, which covers the wavelength range 1.154--1.316 micron:

    BAND=1.154e-6 1.316e-6

  • Find data with wavelength longer than 1.4 micron:

    BAND=1.4e-6 Inf

  • Find data with wavelength shorter than 1.4 micron:

    BAND=-Inf 1.4e-6

  • Find data that includes 2.2 micron:



The COLLECTION parameter identifies the group of data that an observation belongs to.


  • COLLECTION=spitzer_sha
  • COLLECTION=wise_allwise
  • COLLECTION=twomass_allsky

The CALIB parameter identifies the calibration level of an observation. This is useful for distinguishing between raw, processed, and highly processed data that are all part of the same collection. The specific meaning for the different levels are specified in the IVOA ObsCore standard:

  • Level 0: Raw instrumental data, in a proprietary or internal data-provider defined format, that needs instrument specific tools to be handled.
  • Level 1: Instrumental data in a standard format (FITS, VOTable, SDFITS, ASDM, etc.) which could be manipulated with standard astronomical packages.
  • Level 2: Calibrated, science ready data with the instrument signature removed.
  • Level 3: Enhanced data products like mosaics, resampled or drizzled images, or heavily processed survey fields. Level 3 data products may represent the combination of data from multiple primary observations.


  • CALIB=1
  • CALIB=2
  • CALIB=3

The FORMAT parameter constrains which data products are returned based on their data format, as listed in the access_format column


  • FORMAT=application/x-gzip
  • FORMAT=image/fits
  • FORMAT=text/plain

The RESPONSEFORMAT parameter specifies what type of output the service will return. The default is VOTable, but many options are available:



The MAXREC parameter specifies the maximum number of records to retrieve. The default is unlimited. However, any jobs taking longer than 5 minutes will be canceled. For larger jobs, please use TAP


  • MAXREC=0
  • MAXREC=100
  • MAXREC=1000000


  1. Search for ALLWISE images within 10 arcseconds of ra,dec = (19.005875, -5.084472). Return the result as in comma-separated value format.

                wget -O example1.csv ""
  2. Return only the WISE channel 1 data products.

                wget -O example2.csv ""
  3. Return only data products that are FITS images (as opposed to gzipped files or text files).

                wget -O example3.csv ""

Getting Help

If you've run into a problem, think you've found a bug, or simply have questions, please contact IRSA User Support.