SIA2VAOPrototype < IVOA

---+!! VAO SIAv2 Prototype Effort

This page shares information on the VAO Project's effort to prototype an SIAv2 service. The goal is to demostrate key features and uncover practical lessons that can be folded back into the SIAv2 standardization process. 

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---++ Summer 2013 Prototype

In the spring 2013, the VAO, responding to feedback from the Spring 2013 Interop, developed a plan to build an SIAv2 prototype service by the Fall 2013 Interop. In particular, feedback from invited panelists representing leading archives resulted in a focus on basic dataset discovery and retrieval (over more advanced features, such as cutouts or reprojections). The VAO plan has four major phases:
   1 Updating the relevant specifications, namely the Image Data Model WD and the SIAv2 protocol WD.
   1 Defining scope and schedule for the delivered prototype
   1 Implementation using the VAO DalServer code base as the platform
   1 Testing and evaluation of the deployed prototype

---+++ Regarding the Documents Used as Baseline Specifications

It was assumed from the start that the relevant IVOA Working Drafts, namely the SIAv2 prototol specficiation and the Image Data Model specification it is based on--would continue to evolve throughout the development period. For project management, this raise two concerns
   * the scope of the effort would be apt to "creep" to keep up with the evolving document
   * it would be difficult to evaluate our prototype if the specification had evolved away from the version we started with.
To address this problem, it was clear that we needed to "freeze" the pair of documents at a reasonable intermediate version, and then carefully control further changes only as needed to address specific goals and defined scope of our prototype. Meanwhile, the official IVOA WDs can continue to evolve.  Our so-called "VAO Baseline" versions are listed below; they are specially named and labelled to emphasize that these baseline versions do _not_ represent the current versions by the official IVOA SIAv2 editors. Nor are they intended to represent alternative or competing versions. Instead, they should be considered a close approximation to a subset of the SIAv2 capabilties sufficient for gaining experience and insight into implementing a real SIAv2 service.
---+++ Details

   * [[%ATTACHURL%/CubeSchedule-v2.pdf][Requirements, Scope, and Schedule]]
   * VAO Baseline Specifications<span style="color: red;">*</span>:
      * [[%ATTACHURL%/WD-ImageDM-20130811.pdf][ImageDM]]
      * [[%ATTACHURL%/VAO-SIAP-2.0-20130830.pdf][SIAv2]]
   * Test Queries: enumerated below
   * Results: _(IVOA presentation slides)_

<span style="color: red;">*</span>See note above [[#Regarding_the_Documents_Used_as][Regarding the Documents Used as Baseline Specifications]]

---++++ Summary of Scope

This prototype is focused on data discovery and delivery via the =queryData= operation. No cutout or data extraction will be supported; only the download of full single datasets (via the Access.Reference attribute) will be enabled. Synchronous queries are supported only. The focus of our testing will be on the required query parameters; no support for the optional parameters is planned. 

---++++ Test Queries

---+++++ Selected Coverage Queries

| *Title*                    | return all images in a square region |
| *Query*                 | =/sync?REQUEST=querydata&POS=202.48416,+47.23055&SIZE=0.033=  |
| *Should Return*    | VOTable listing 4 heracles images of  NGC 519                |

| *Title*                    | return all images in a rectangular region |
| *Query*                 |  =/sync?REQUEST=querydata&POS=245,10&SIZE=2,4=  |
| *Should Return*    | VOTable listing 4 califa images                   |

| *Title*                    | return all images in a region with supported frame |
| *Query*                 |  =/sync?REQUEST=querydata&POS=245,10;ICRS&SIZE=2,4=  |
| *Should Return*    | VOTable listing 4 califa images                   |

| *Title*                    | restrict to spectral window               |
| *Query*                 | =/sync?REQUEST=querydata&BAND=0.21/0.22=               |
| *Should Return*    | VOTable listing 5 NED images and 5 VLA images                 |

| *Title*                    | restrict to sky region and spectral window               |
| *Query*                 | =/sync?REQUEST=querydata&POS=21,+3.6;ICRS&SIZE=0.5&BAND=0.21/0.22=               |
| *Should Return*    | VOTable listing one NED image and 1 VLA image                 |

| *Title*                    | Time Coverage                   |
| *Query*                 | =/sync?REQUEST=querydata&TIME=1992-01-01/1997-01-01=    |
| *Should Return*    | VOTable listing two NED image and 2 VLA image                  |


---+++++ Polarization

| *Title*                    | Stokes V coverage                   |
| *Query*                 | =/sync?REQUEST=querydata&POL=V=    |
| *Should Return*    | VOTable listing only images with  Stokes V coverage                 |

| *Title*                    | Any polarization                   |
| *Query*                 | =/sync?REQUEST=querydata&POL=any=    |
| *Should Return*    | VOTable listing all images                  |

| *Title*                    | Stokes I polarization                   |
| *Query*                 | =/sync?REQUEST=querydata&POL=I=    |
| *Should Return*    | VOTable listing all images that represent measurements of total intensity.  This should include any images that do not explicitly measure polarization.              |

---+++++ General Protocol Testing

| *Title*                    | Erroneous Query               |
| *Query*                 | =/sync?REQUEST=querydata&POS=asdfl&SIZE=0.1=               |
| *Should Return*    | VOTable with properly set INFO specifying error                  |

| *Title*                    | return all images in a region with unsupported frame |
| *Query*                 |  =/sync?REQUEST=querydata&POS=245,10;GALACTIC&SIZE=2,4=  |
| *Should Return*    | VOTable with error contents indicating unsupported frame                   |

| *Title*                    | Metadata Query    |
| *Query*                 | =/sync?REQUEST=querydata&FORMAT=metadata=  <br/> =/sync?maxrec=0=   |
| *Should Return*    | a VOTable with a fully specified table header but no rows                  |

| *Title*                    | FITS Format Query     |
| *Query*                 | =/sync?REQUEST=querydata&FORMAT=image/fits=   |
| *Should Return*    | a VOTable listing all our images                  |

| *Title*                    | Unsupported Format Query     |
| *Query*                 | =/sync?REQUEST=querydata&FORMAT=image/jpeg=   %BR%  =/sync?REQUEST=querydata&FORMAT=graphic=    |
| *Should Return*    | a VOTable listing no images (since we are not supporting this format)                 |



---+++ Progress
---++++ 03-Sep-2013

We have collected approximately a dozen FITS image cube datasets (including ones from JVLA, CARMA, JCMT, Chandra, and JWST) representing a variety of important types of features. We determined the set of metadata that we will capture for this data and expose through the service, and we have an initial version of the extracted metadata. The service is in development within the DALServer framework, set to be ready for testing by Sept. 6. Currently, the software currently supports creation of the output VOTable response to a =queryData= request; while the table is empty, the table columns are fully specified with the proper UTypes defined by the ImageDM. 

---++++ 13-Sep-2013

The completed software was delivered into our SVN repository on Sept. 9, and the service instance for evaluation  has been deployed at http://vaosa-vm1.aoc.nrao.edu/ivoa-dal/siapv2/sync on Sept. 10.  Testing is now underway, with bug reports resulting in code updates and redeployment of the service.  

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Attachments
Topic attachments
I	Attachment	History	Action	Size	Date	Who
pdf	CubeSchedule-v2.pdf	r1	manage	198.2 K	2013-09-03 - 16:24	RayPlante
pdf	VAO-SIAP-2.0-20130830.pdf	r1	manage	927.0 K	2013-09-03 - 16:26	RayPlante
pdf	WD-ImageDM-20130811.pdf	r1	manage	1120.8 K	2013-09-03 - 16:26	RayPlante
This topic: IVOA > WebHome > IvoaDAL > SiaInterface > SIA2VAOPrototype
Topic revision: r2 - 2013-09-11 - RayPlante