Spectral cutout service

[Douglas Tody]

Hi Petr -

SSAP supports cutouts in just the same sense that SIAP does: you
specify the region of interest (ROI), and if the service is a cutout
service it computes a spectra to fit the ROI.  For a spectra, BAND
is what gives you the cutout, whereas for an image it is POS,SIZE
(and for a time series it would be TIME).

For typical lowres survey spectra cutouts are probably not that
useful, but it should be a useful feature for any highres spectra.
In particular it could be used to get line profiles.

While this is the intention, I am yet not aware of any SSAP services 
that can do cutouts.

Note that none of the "typed" DAL interfaces are limited to merely
returning archival (whole) datasets; they all do virtual data
generation (subset, filter, transform).  Only the planned generic
dataset is limited to archival data access, however it will have
other capabilities, e.g., for association to describe complex data
aggregations.

 	- Doug


On Tue, 30 Sep 2008, Petr Skoda wrote:

>
> Hi all,
>
> Has been someone working on a implementation of a simple implementation of
> a service delivering through SSAP not whole spectrum but only part of it in 
> selected wavelength range?
>
> I am not able to find anything in SSAP 1.04 concerning the relevant 
> parameters. As I understand the BAND should be used to only impose additional 
> constraint on selection of spectra.
> But if there is no  better way I would try to create 2 services with 
> different serviceURL to the same archive but for the cutout the BAND would 
> mean - select all spectra containing that range AND cut them to those limits 
> before sending.
>
> Or is there another parameter conceived for this purpose (e.g.
> CUTRANGE=wave_min/wave_max or CUTBAND ?
>
> Or to do the cutout as default and device parametr for delivering whole 
> spectrum ?
>
> What do you suggest ? Is there anything established for image cutouts ?
> What is the current support of BAND in VO spectral clients ?
>
> Thanks
>
> Petr Skoda
>
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