Note this is now out-of-date.
This image shows the browser window of SPLAT. This is the main
window where a list of all the spectra (and their plotting properties)
is maintained (the Global list of spectra:). To interact with
the VO you need to select the SSAP item in the File
menu, or you can press the toolbar button.
Query VO for Spectra
This window provides basic access to the VO. Using it you can query the
current list of SSAP servers (Simple Spectral Access Protocol) for lists
of the spectra that they hold about a circular region on the sky. You
can then select which of these you are interested in and download these
To locate an object you can look it's celestial coordinates (using
SIMBAD or NED, see the Resolver menu), that's what's shown above
(you press Lookup and the RA: and Dec: fields are
filled), or you can just type in the coordinates, which can also be in
decimal degress (all coordinates are assumed to be in FK5/J2000). The
Radius field is the number of arcminutes to search around the
position. Now that we've done that we can press Go and the search
will be performed.
The search is done asynchronously so that each of the SSAP
servers responds when it can. You can cancel any query that seems to be
unresponsive. Close that window and you'll now see that the
Query results: area is now filled with a series of tabs that,
when pressed, reveal the spectra available from each server.
The simplest way to download a spectrum is to double click on the
line. Alternatively you can select as many spectra as you want (using
the usual Control-click to add more spectra to a selection, or
Shift-click to select a range) and then press Display
selected. Pressing Display all may seem like a good idea, but
you'll need to be patient.
Once a spectrum has been downloaded it will appear in the Global
list and be displayed in a plot window.
If you download more than one spectrum they will be displayed in the
The following is a selected set of spectra for a similar search based
around the position of Beta UMi.
Configuring the SSAP servers
The SSAP servers used during the query may be configured
using the Options Configure SSAP servers... dialog
window (or you can just press ).
Using this window you can remove any servers that you don't want to
query and, more importantly, you can query the registry of
SSAP servers for any new services (the initial set used are a
static list). You do this by pressing the Query registry
button. Subsets of services can be created and saved/restored.