Simple Image Access v1 Queries

Overview

The IRSA implementation of the IVOA SIA v1 specification allows users to query the many of the major IRSA holdings. This API has been superceded by IRSA's SIA V2 API and new queries should be written using the newer API.

The URL for IRSA SIA v1 queries takes the form of:

https://irsa/ipac.caltech.edu/ibe/sia/{mission}/{data-set}/{table-name}?{query-constraints}

The only missions supported by this service are WISE, 2MASS, and PTF and the possible values for {mission}, {data-set}, and {table-name} are shown in the table below.

Available data-sets

The table below lists all of the data sets that can be used with this service. The link in the "Description" column goes to detailed information regarding the use of the table with the IRSA Image Service API. The link in the "table-name" column displays all of the columns available for the table.

Description mission data-set table-name
2MASS All-Sky Image Metadata Table 2mass allsky allsky
2MASS Full Survey Atlas Image Metadata Table 2mass full full
2MASS Long Exposure (6X) Full Survey Atlas Image Metadata Table 2mass sixxfull sixxfull
2MASS Long Exposure (6X) Atlas Image Metadata Table 2mass sixxcat sixxcat
2MASS Calibration Scan Atlas Image Metadata Table 2mass calibration calibration
2MASS 6-Degree Mosaic Image Metadata Table 2mass mosaic sixdeg
AllWISE Atlas Image Inventory Table wise allwise p3am_cdd
NEOWISE-R Single Exposure (L1b) Image Inventory Table wise neowiser p1bm_frm
WISE 2-Band Post-Cryo Single Exposure (L1b) Image Inventory Table wise postcryo 2band_p1bm_frm
WISE 3-Band Cryo Atlas Image Inventory Table wise cryo_3band 3band_p3am_cdd
WISE 3-Band Cryo Single Exposure (L1b) Image Inventory Table wise cryo_3band 3band_p1bm_frm
WISE All-Sky Atlas Image Inventory Table wise allsky 4band_p3am_cdd
WISE All-Sky Single Exposure (L1b) Image Inventory Table wise allsky 4band_p1bm_frm
WISE Preliminary Release Single Exposure (L1b) Image Inventory Table (Superseded) wise prelim p1bm_frm
WISE Preliminary Release Atlas Image Inventory Table (Superseded) wise prelim p3am_cdd
WISE Preliminary 2-Band Post-Cryo Single Exposure (L1b) Image Inventory Table (Superseded) wise prelim_postcryo p1bm_frm
PTF Level 1 Images ptf images level1
PTF Level 2 Images ptf images level2

Query Constraints

An SIA v1 query returns a table of files satisfying the constraints of the query. SIA v1 constraints are entirely limited to spatial queries using the POS, SIZE, and INTERSECT parameters. The default results from SIA v1 queries are VO Tables, but many formats are available through RESPONSEFORMAT.

SIA v1 Query Parameters:

POS

The POS parameter defines the central position of the search region of interest. The position is given by two values separated by a comma (',') with no whitespace. Values are right ascension and declination in decimal degrees using the ICRS coordinate system.

Examples:

  1. A postion centered on (164.7, -5.8):

    POS=164.7,-5.8

  2. A postion centered on (12.34, 5.09):

    POS=12.34,5.09

SIZE

The SIZE parameter defines the angular region of interest centered about POS. The region can be provided using one or two values, which have units of decimal degrees. If only one value is given, it applies to both axes. For two values, the numbers must be separated by a comma (',') with no whitespace; the first number is the angular width along the right ascension axis and the second number is the width along the declination axis. The region defined by this parameter assumes no rotation.

Examples:

  1. A region of interest with lengths 0.2 degrees along the right ascension and declination axes:

    SIZE=0.2

  2. A region of interest with a size of 0.1 degrees in the right ascension axis and 0.5 degrees in the declination axis:

    SIZE=0.1,0.5

  3. Find data that contains the search position:

    SIZE=0

INTERSECT

The INTERSECT parameter defines how the matched images should intersect the search region. The allowed values are:

  • COVERS: The image covers the entire search region.
  • ENCLOSED: The image is entirely enclosed by the search region.
  • CENTER: The image overlaps the center of the search region.
  • OVERLAPS: The image overlaps with some part of the search region.

Examples:

  • INTERSECT=COVERS
  • INTERSECT=ENCLOSED
  • INTERSECT=CENTER
  • INTERSECT=OVERLAPS

INTERSECT=OVERLAPS is assumed if this parameter is not included in the query.

FORMAT

The FORMAT parameter defines what data should be returned by the query. The allowed values are:

  • ALL: Return all images matching the query contraints.
  • METADATA: Ignore the query contraints and return the metadata for the requested dataset.

Examples:

  • FORMAT=ALL
  • FORMAT=METADATA

FORMAT=ALL is assumed if this parameter is not included in the query.

RESPONSEFORMAT

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

Examples:

Examples

  1. Return the metadata for the 2MASS AllSky image table.

          curl -o example1.xml "https://irsa.ipac.caltech.edu/ibe/sia/twomass/allsky/allsky?FORMAT=METADATA"

  2. Search for AllWISE coadds that completely contain a search region that is 0.5 degree by 0.2 degrees and centered on ra = 20 degrees, dec = 40 degrees.

          curl -o example2.xml "https://irsa.ipac.caltech.edu/ibe/sia/wise/allwise/p3am_cdd?POS=20,40&SIZE=0.5,0.2&INTERSECT=COVERS"

  3. Search for NEOWISE-R single frame images that overlaps with a search region that is 0.2 degree on a side and centered on ra = 12.5 degrees, dec = -30.6 degrees.

          curl -o example3.xml "https://irsa.ipac.caltech.edu/ibe/sia/wise/neowiser/p1bm_frm?POS=12.5,-30.6&SIZE=0.2&INTERSECT=OVERLAPS"

Getting Help

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