<html><head><meta http-equiv="Content-Type" content="text/html; charset=utf-8"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class="">Hi Mark, <div class=""><br class=""></div><div class="">Thanks for your comment and spotting that! I agree with relaxing the language following your suggestion. </div><div class=""><br class=""></div><div class="">Cheers,</div><div class="">Ada</div><div class=""> <br class=""><div class="">
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<div><br class=""><blockquote type="cite" class=""><div class="">On 12 Mar 2021, at 15:14, Mark Taylor <<a href="mailto:m.b.taylor@bristol.ac.uk" class="">m.b.taylor@bristol.ac.uk</a>> wrote:</div><br class="Apple-interchange-newline"><div class=""><div class="">Pierre, Ada and MOC authors,<br class=""><br class="">the VODataService 1.2 PR<br class="">(<a href="https://wiki.ivoa.net/twiki/bin/view/IVOA/VODataServiceV12RFC" class="">https://wiki.ivoa.net/twiki/bin/view/IVOA/VODataServiceV12RFC</a>)<br class="">is planning to permit use of MOCs for coverage information,<br class="">and currently contains the text:<br class=""><br class=""> "By default, the MOCs are to be interpreted in the ICRS. <br class=""> Future extensions to non-celestial frames (e.g., on planet surfaces) <br class=""> will use the frame attribute. However, the only celestial reference <br class=""> system allowed is ICRS."<br class=""><br class="">I don't think that this conflicts with the spirit of the MOC text<br class="">(no galactic/ecliptic sky coordinate systems allowed), but the <br class="">existing MOC 2.0 draft currently has language like:<br class=""><br class=""> Consequently, the SMOC MUST be based on the HEALPix tessellation<br class=""> of the sphere, expressed in the ICRS coordinate reference system.<br class=""><br class="">which appears to exclude the possibility of using MOC with any non-sky<br class="">coordinate system.<br class=""><br class="">Could we consider relaxing the language to make it clear that MOC<br class="">use on the sky is required to use ICRS, but future applications to<br class="">non-sky domains are not prohibited?<br class=""><br class="">Mark<br class=""><br class="">--<br class="">Mark Taylor Astronomical Programmer Physics, Bristol University, UK<br class=""><a href="mailto:m.b.taylor@bristol.ac.uk" class="">m.b.taylor@bristol.ac.uk</a> <a href="http://www.star.bristol.ac.uk/~mbt/" class="">http://www.star.bristol.ac.uk/~mbt/</a><br class=""></div></div></blockquote></div><br class=""></div></body></html>