<div dir="ltr"><div>It's also explicitly referred to in WCS paper IV.<br><br></div> - Arnold<br></div><div class="gmail_extra"><br clear="all"><div><div class="gmail_signature"><div dir="ltr">-------------------------------------------------------------------------------------------------------------<br>Arnold H. Rots Chandra X-ray Science Center<br>Smithsonian Astrophysical Observatory tel: +1 617 496 7701<br>60 Garden Street, MS 67 fax: +1 617 495 7356<br>Cambridge, MA 02138 <a href="mailto:arots@cfa.harvard.edu" target="_blank">arots@cfa.harvard.edu</a><br>USA <a href="http://hea-www.harvard.edu/~arots/" target="_blank">http://hea-www.harvard.edu/~arots/</a><br>--------------------------------------------------------------------------------------------------------------<br><br></div></div></div>
<br><div class="gmail_quote">On Mon, Jun 22, 2015 at 3:04 PM, Bob Garwood <span dir="ltr"><<a href="mailto:bgarwood@nrao.edu" target="_blank">bgarwood@nrao.edu</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">The Green Bank convention is mentioned in WCS Paper I. It's also used in the example header shown in Table 9 (apparently taken from a real example known to one of the authors) of WCS Paper 2, where 4 2048x2048 images are stored in separate rows of a table. All 4 images share most of the same WCS except for the reference pixels on each axis. keywords are used for most of the WCS, but columns are used to store the reference pixels. That's the Green Bank convention.<span class="HOEnZb"><font color="#888888"><br>
<br>
Bob</font></span><div class="HOEnZb"><div class="h5"><br>
<br>
On 06/22/2015 02:43 PM, THIERRY FORVEILLE wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
The proposed draft text is available at<br>
<a href="http://sax.iasf-milano.inaf.it/~lucio/FITS/Conventions/greenbank-upd2.pdf" rel="noreferrer" target="_blank">http://sax.iasf-milano.inaf.it/~lucio/FITS/Conventions/greenbank-upd2.pdf</a><br>
</blockquote>
I have to say I find way of storing images pretty confusing. What's the<br>
advantage of storing them this way instead of creating separate FITS<br>
extensions?<br>
<br>
</blockquote>
The context of the use cases that I know of is one where the images are 1D<br>
(single-dish radioastronomical spectra), small (O(1Kpixels)), and numerous<br>
(O(10^4)). Creating separate FITS extension would waste significant space<br>
(of order a factor of two), and also would not outline as well the structural<br>
unity of the dataset.<br>
<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
Is it just of historical interest?<br>
<br>
</blockquote>
The convention is in use in single dish radio-astronomy. I don't know of<br>
any use case outside that field.<br>
<br>
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