The United States Naval Observatory (USNO) — Naval Oceanography Portal

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<tbody> <tr> <td id="portal-column-one"> <div class="visualPadding"> <div id="portletwrapper-706c6f6e652e6c656674636f6c756d6e0a636f6e746578740a2f4e4f502f55534e4f0a75736e6f" class="portletWrapper kssattr-portlethash-706c6f6e652e6c656674636f6c756d6e0a636f6e746578740a2f4e4f502f55534e4f0a75736e6f"><div class="portletStaticText portlet-static-usno"> <p class="usnoNavBar"><a title="U.S. Naval Observatory" class="internal-link" href="resolveuid/d620748b5710e29925fc70fc23d8dc0a"><img class="image-inline" src="/web/20101224092047im_/http://www.usno.navy.mil/USNO/resolveuid/35b9091ac36ef12dde5290a53498997e/image_preview" alt="USNO Logo"/></a> <a title="U.S. Naval Observatory" class="internal-link" href="resolveuid/d620748b5710e29925fc70fc23d8dc0a">USNO</a></p> </div> </div> <div id="portletwrapper-706c6f6e652e6c656674636f6c756d6e0a636f6e746578740a2f4e4f502f55534e4f0a6e617669676174696f6e" class="portletWrapper kssattr-portlethash-706c6f6e652e6c656674636f6c756d6e0a636f6e746578740a2f4e4f502f55534e4f0a6e617669676174696f6e"> <dl class="portlet portletNavigationTree"> <dt class="portletHeader"> <span class="portletTopLeft"></span> <a href="https://web.archive.org/web/20101224092047/http://www.usno.navy.mil/USNO/sitemap" class="tile">USNO Nav Bar</a> <span class="portletTopRight"></span> </dt> <dd class="portletItem lastItem"> <ul class="navTree navTreeLevel0"> <li class="navTreeItem visualNoMarker navTreeFolderish"> <div> <a href="https://web.archive.org/web/20101224092047/http://www.usno.navy.mil/USNO/astrometry" class="state-published navTreeFolderish" title="The Astrometry Product Center"> <img width="16" height="16" src="https://web.archive.org/web/20101224092047im_/http://www.usno.navy.mil/folder_icon.gif" alt="Folder"/> <span>Astrometry</span> </a> </div> </li> <li class="navTreeItem visualNoMarker navTreeFolderish"> <div> <a href="https://web.archive.org/web/20101224092047/http://www.usno.navy.mil/USNO/astronomical-applications" class="state-published navTreeFolderish" title="The Astronomical Applications Product Center"> <img width="16" height="16" src="https://web.archive.org/web/20101224092047im_/http://www.usno.navy.mil/folder_icon.gif" alt="Folder"/> <span>Astronomical Applications</span> </a> </div> </li> <li class="navTreeItem visualNoMarker navTreeFolderish"> <div> <a href="https://web.archive.org/web/20101224092047/http://www.usno.navy.mil/USNO/earth-orientation" class="state-published navTreeFolderish" title="The Earth Orientation Product Center"> <img width="16" height="16" src="https://web.archive.org/web/20101224092047im_/http://www.usno.navy.mil/folder_icon.gif" alt="Folder"/> <span>Earth Orientation</span> </a> </div> </li> <li class="navTreeItem visualNoMarker navTreeFolderish"> <div> <a href="https://web.archive.org/web/20101224092047/http://www.usno.navy.mil/USNO/time" class="state-published navTreeFolderish" title="USNO Timing Products"> <img width="16" height="16" src="https://web.archive.org/web/20101224092047im_/http://www.usno.navy.mil/folder_icon.gif" alt="Folder"/> <span>Precise Time</span> </a> </div> </li> <li class="navTreeItem visualNoMarker navTreeFolderish"> <div> <a href="https://web.archive.org/web/20101224092047/http://www.usno.navy.mil/USNO/library" class="state-published navTreeFolderish" title=""> <img width="16" height="16" src="https://web.archive.org/web/20101224092047im_/http://www.usno.navy.mil/folder_icon.gif" alt="Folder"/> <span>James M. Gilliss Library</span> </a> </div> </li> <li class="navTreeItem visualNoMarker navTreeFolderish"> <div> <a href="https://web.archive.org/web/20101224092047/http://www.usno.navy.mil/USNO/tours-events" class="state-published navTreeFolderish" title=""> <img width="16" height="16" src="https://web.archive.org/web/20101224092047im_/http://www.usno.navy.mil/folder_icon.gif" alt="Folder"/> <span>Tours & Events</span> </a> </div> </li> <li class="navTreeItem visualNoMarker navTreeFolderish"> <div> <a href="https://web.archive.org/web/20101224092047/http://www.usno.navy.mil/USNO/about-us" class="state-published navTreeFolderish" title="General Information About the Observatory"> <img width="16" height="16" src="https://web.archive.org/web/20101224092047im_/http://www.usno.navy.mil/folder_icon.gif" alt="Folder"/> <span>About Us</span> </a> </div> </li> </ul> <span class="portletBottomLeft"></span> <span class="portletBottomRight"></span> </dd> </dl> </div>   </div> </td> <td id="portal-column-content"> <div class=""> <div id="region-content" class="documentContent"> <span id="contentTopLeft"></span> <span id="contentTopRight"></span> <a name="documentContent"></a> <dl class="portalMessage info" id="kssPortalMessage" style="display:none"> <dt>Info</dt> <dd></dd> </dl> <div id="viewlet-above-content"></div> <div id="content"> <h1 class="documentFirstHeading"> <span class="" id="parent-fieldname-title"> The United States Naval Observatory (USNO) </span> </h1> <p class="documentDescription"> <span class="" id="parent-fieldname-description"> 3450 Massachusetts Ave, NW, Washington, DC 20392-5420 </span> </p> <div class="" id="parent-fieldname-text"> <img class="image-right" src="/web/20101224092047im_/http://www.usno.navy.mil/USNO/usno-images/Urania_Clear_1.jpg" alt="Urania Clear" height="309" width="333"/> <p>The United States Naval Observatory (USNO) provides a wide range of astronomical data and products, and serves as the official source of time for the U.S. Department of Defense and a standard of time for the entire United States.</p> <p>USNO products support activities in the following areas:</p> <h2 class="heading"><a title="Astrometry" class="internal-link" href="/web/20101224092047/http://www.usno.navy.mil/USNO/astrometry"><span class="Apple-style-span">Astrometry</span></a></h2> <p>Integrated Image and Catalog Archive Service, star catalogs, fundamental reference frames, space astrometry.</p> <h2 class="heading"><a title="Astronomical Applications" class="internal-link" href="/web/20101224092047/http://www.usno.navy.mil/USNO/astronomical-applications">Astronomical Applications</a></h2> <p>Astronomical data calculators (e.g., rise/set times, Moon phase, etc.), information on astronomical phenomena and related topics, astronomical and navigational almanacs, software products.</p> <h2 class="heading"><a title="Earth Orientation" class="internal-link" href="/web/20101224092047/http://www.usno.navy.mil/USNO/earth-orientation">Earth Orientation</a></h2> <p>Daily, weekly, and long-term EO products (e.g. IERS Bulletin A), GPS-based products (rapids, ultra-rapids, UTGPS), VLBI-based products, background information, technical and scientific publications and software.</p> <h2 class="heading"><a title="Time" class="internal-link" href="/web/20101224092047/http://www.usno.navy.mil/USNO/time">Precise Time</a><br/></h2> <p>USNO Master Clock, Network Time Protocol (NTP) servers, web-based time synchronization, GPS timing products and services, Two-Way Satellite Time Transfer, and Loran-C timing products.</p> <h2 class="heading"><a title="James M. Gilliss Library" class="internal-link" href="/web/20101224092047/http://www.usno.navy.mil/USNO/library">The James M. Gilliss Library</a></h2> <p>USNO's library holds one of the most complete collections of astronomical literature in the world.</p> <h2 class="heading"><a title="Tours & Events" class="internal-link" href="/web/20101224092047/http://www.usno.navy.mil/USNO/tours-events">Tours & Events</a></h2> <p>Information on tours of the Naval Observatory, upcoming scientific colloquia, and other events.</p> <p><span class="Apple-style-span"> <h2 class="heading"><a title="About Us" class="internal-link" href="/web/20101224092047/http://www.usno.navy.mil/USNO/about-us">About Us</a></h2> <p>Information about the U.S. Naval Observatory.</p> </span></p> <p> </p> <p><span class="Apple-style-span"><br/></span></p> <p><span class="Apple-style-span"><span class="Apple-style-span"><br/></span></span></p> </div> <div class="relatedItems"> </div> <div class="reviewHistory" id="review-history"> </div> </div> <span id="contentBottomLeft"></span> <span id="contentBottomRight"></span> </div> </div> </td> <td id="portal-column-two"> <div class="visualPadding"> <div id="portletwrapper-706c6f6e652e7269676874636f6c756d6e0a636f6e746578740a2f4e4f502f55534e4f0a75736e6f2d6d61737465722d636c6f636b2d74696d65" class="portletWrapper kssattr-portlethash-706c6f6e652e7269676874636f6c756d6e0a636f6e746578740a2f4e4f502f55534e4f0a75736e6f2d6d61737465722d636c6f636b2d74696d65"> <dl class="portlet portletStaticText portlet-static-usno-master-clock-time"> <dt class="portletHeader"> <span class="portletTopLeft"></span> <span> USNO Master Clock Time </span> <span class="portletTopRight"></span> </dt> <dd class="portletItem odd"> <div id="USNOtime" class="USNOtime">Javascript must be Enabled</div> <span class="portletBottomLeft"></span> <span class="portletBottomRight"></span> </dd> </dl> </div> <div id="portletwrapper-706c6f6e652e7269676874636f6c756d6e0a636f6e746578740a2f4e4f502f55534e4f0a7468652d736b792d746869732d7765656b" class="portletWrapper kssattr-portlethash-706c6f6e652e7269676874636f6c756d6e0a636f6e746578740a2f4e4f502f55534e4f0a7468652d736b792d746869732d7765656b"><dl class="portlet portletCollection"> <dt class="portletHeader"> <span class="portletTopLeft"></span> <a href="https://web.archive.org/web/20101224092047/http://www.usno.navy.mil/USNO/tours-events/sky-this-week/the-sky-this-week"> <span>The Sky This Week</span> </a> <span class="portletTopRight"></span> </dt> <dd class="portletItem odd"> <a href="https://web.archive.org/web/20101224092047/http://www.usno.navy.mil/USNO/tours-events/sky-this-week/the-sky-this-week-2010-december-21-31" class="tile" title="Our annual Homage to Clement Clark Moore"> <img width="16" height="16" src="https://web.archive.org/web/20101224092047im_/http://www.usno.navy.mil/document_icon.gif" alt="Page"/> The Sky This Week, 2010 December 21 - 31 </a> </dd> <dd class="portletFooter"> <span class="portletBottomLeft"></span> <span> <a href="https://web.archive.org/web/20101224092047/http://www.usno.navy.mil/USNO/tours-events/sky-this-week/the-sky-this-week"> More… </a> </span> <span class="portletBottomRight"></span> </dd> </dl> </div>   </div> </td> </tr> </tbody> </table> <div class="visualClear" id="clear-space-before-footer"></div> <div id="portal-footer"> <p> Naval Meteorology and Oceanography Command,    1100 Balch Blvd,   Stennis Space Center, MS 39529 </p> <p> <span omit-tag=""> <a href="https://web.archive.org/web/20101224092047/http://www.cffc.navy.mil/">Fleet Forces Command</a>   |    </span> <a href="https://web.archive.org/web/20101224092047/http://www.navy.com/">navy.com</a>   |    <a href="https://web.archive.org/web/20101224092047/http://www.foia.navy.mil/">Freedom of Information Act (FOIA)</a>   |    <a href="https://web.archive.org/web/20101224092047/http://www.usno.navy.mil/external-link-disclaimer">External Link Disclaimer</a> </p> </div> <div id="portal-colophon"> <div class="colophonWrapper"> <ul>  <li> This is an official <a href="https://web.archive.org/web/20101224092047/http://www.navy.mil/"> U.S. Navy</a> web site. </li> <li> <a href="https://web.archive.org/web/20101224092047/http://www.usno.navy.mil/privacy-policy">Security & Privacy Policy</a> </li> </ul> </div> </div> <div class="visualClear"></div> </div> <div id="kss-spinner"><img alt="" src="https://web.archive.org/web/20101224092047im_/http://www.usno.navy.mil/spinner.gif"/></div> </body> </html>

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The United States Naval Observatory (USNO) — Naval Oceanography Portal