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Digitised Sky Survey
Batch request help The DSS
Batch Request system allows the user to submit up to 15 source
positions at once, and obtain GIF, FITS or NDF images of the Digitised Sky Survey
fields surrounding those objects. The images may be viewed individually, or downloaded
as a single tarfile archive. The following information must be specified for
each object: RA and Dec of field centre (in sexigesimal format, either B1950 or
J2000 epoch), image height (in arcsec), image width (in arcsec) and pixel size
(in arcsec). Once all images have been retrieved, a table will be displayed
where individual DSS frames can be selected and downloaded. RestrictionsThe
following restrictions apply to batch image requests:-
- The field
size must be larger than 17", and smaller than 30 arcmin.
- A maximum of 15 sources may be submitted in one request.
Service timeThe time taken to service a request depends on the size of
the requested image, and whether it overlaps the edge of a plate. A typical 15'x15'
image close to the centre of a plate will be returned in around 10 seconds or
less, whereas a 1x1 degree image could overlap three or four separate plates,
and may take a minute or more to be fulfilled. Batch requests for multiple images
will be a corresponding multiple of this figure. If an error message 'document
contains no data' is obtained, this may be due to the browser request timing
out before the server has returned the data. Try reducing the number or size of
images requested. If the problem persists, contact LEDAS
Support. Back to Request Form
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