<div dir="ltr"><div>Dear Gilles,</div><div>thank you for keeping focus on this.</div><div>I add DAL group to the recipients, being ObjVisSAP an access protocol.</div><div><br></div><div>Cheers</div><div> Marco</div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">Il giorno mar 21 mag 2019 alle ore 14:25 Gilles Duvert <<a href="mailto:gilles.duvert@univ-grenoble-alpes.fr">gilles.duvert@univ-grenoble-alpes.fr</a>> ha scritto:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
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Dears,<br>
<br>
The <a href="http://ivoa.net/documents/ObjVisSAP/index.html" target="_blank">Object
Visibility Simple Access Protocol</a> WD uses the term
"visibility" in the general acceptance, "being visible".<br>
However, "visibility" is unfortunately widely used in the
interferometric community for (in short) naming the value of the
fringe contrast. As such, "visibility" data are exposed and queried
in the VO---that have nothing to do with OVSAP topic. <br>
<br>
When both concepts are present, such as in the <a href="http://www.jmmc.fr/aspro_page.htm" target="_blank">VO
tool Aspro</a>, interferometric visibilities are "visibilities"
and the concept of an object "visible" above the horizon of a given
observatory/telescope/interferometer is termed "observability", so
Aspro can happily plot "observability tracks" atop a "visibility"
map. <br>
Worse, "Object Visibility" is also widely used in the literature as
refering to the interferometric fringe contrast of an (astronomical)
object.<br>
On the other hand, the <a href="https://www.eso.org/sci/observing/phase2/p2intro.html" target="_blank">p2web</a>
ESO tool refers to a "Target Visibility" with the same meaning as in
OVSAP. "Target" is precise in the context of a facility, "Object" is
the science counterpart of the target. <br>
<br>
This semantic clash was reported as an issue during last week's
Interop. May I suggest, since this very useful WD is now reaching
version 1.0, to circumvent any potential problem by being more
precise, e.g., avoiding the use of the terms "visibility" and
"object visibility", in favor of the compound "Target Visibility" ?<br>
<br>
Of course interferometry-related normalizing documents should
somehow become aware of the synonym, this is another story.<span class="gmail-m_4502887290538947375moz-smiley-s1"><span>:-)</span></span><br>
<br>
Kind Regards,<br>
Gilles Duvert<br>
<br>
<br>
<br>
<br>
</div>
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