Lessons learnt with Aladin and characterization experience for

SIA2.0F.Bonnarel, CDS

(credit to Aladin developpers, CADC,ECF,ESAC, ESO VO people,

DAL and DM IVOA WG)

SIA 1.0 (2002 !!!)

• Pros:– Solved the availabilty issue in a standard way for the first time.– Gave some rather unformal description/characterization of the

images

• Limitations: – No mapping on datamodel – Ad hoc UCDS and no utypes– No structuration of the query response. – No staging

Query phase: extended ROI

• Extend ROI requests to all or a significant subset of stc AstroCoordArea– Use case: Draw a contour on top of a

Preview or a wide field image and use

it as a ROI.– Trick : drawn contours are on the image plane

How to translate that in string stc in some given coordinate system….

SIA 2.0 Query interface: SSA 1.0 + ???

• Requests by more characterization utypes (sampling in combination with resolution)

• More request by ranges (resolution and sampling)

• Add query by Observation/characterization utypes using « utype Extended » ADQL as it is proposed for TAP (non redondant with parameter= value for level 3 or 4

queries)?

Query response: extended datamodel usage

• Use of Curation, Target, DatasetID and Characterization as in SSA.

• Extend SSA Characterization package towards full level 2 for resolutions and sampling for spatial and additional sampled axes ( spectral or whatever)

• Level 3 and Level 4 maybe available through DAL Extension mechanism (described in SSA):– Level 3 example : footprint description– Level 4 = PSF described as a link to a PSF service (eg

TERAPIX qualityfits ) JPEG visualized in Aladin– Level 4 = Filter transmission curve available in Aladin

Query response: Dataset linkage

• Provenance:– instrumental (heavy stuff in FITS keywords)– Processing ( calibration --- links to unprocessed data, ancillary

data)• Access and views of complex or heterogeneous data (Linkage

model) – Linkage to some simple derived datasets or excerpts of the

main dataset (heterogeneous DAL protocols, generic dataset discovery)

• Parallel development of a provenance or dataset linkage datamodel by DM WG

Staging/Asynchronous access

• Individual images may need heavy statistical processing (Bayesian fusion, Markov multispectral segmentation)

– as eg CDS/LSIIT collaboration has shown.

• Extremly faint source detection

• Image cleaning from cosmics …

• Nice to get staging facility to access results later from another aladin session replaying the original images sequences for comparison…

– Idea: original query response give acref to process follow up page,

– replaced by standard DAL (image, spectrum, table) query response when processing is completed

– Interface has only to keep track of original acref ….