GPS satellites good geometry for Global Dillution of Precision (GDOP).
<ul><li><a href="//commons.wikimedia.org/wiki/File:Clear_sky.JPG" title="File:Clear sky.JPG">Clear_sky.JPG</a>: <a href="//commons.wikimedia.org/wiki/User:Suguru@Musashi" title="User:Suguru@Musashi">Suguru@Musashi</a>/<a href="https://ja.wikipedia.org/wiki/%E5%88%A9%E7%94%A8%E8%80%85:%E5%AE%AE%E6%9C%AC%E3%81%99%E3%81%90%E3%82%8B" class="extiw" title="ja:利用者:宮本すぐる">宮本すぐる</a></li>
<li><a href="//commons.wikimedia.org/wiki/File:Garmin_eTrex_Legend_C_in_hand.jpg" title="File:Garmin eTrex Legend C in hand.jpg">Garmin_eTrex_Legend_C_in_hand.jpg</a>: <a rel="nofollow" class="external text" href="https://www.flickr.com/people/45581782@N00">Paul Downey</a> from Berkhamsted, UK</li>
<li><a href="//commons.wikimedia.org/w/index.php?title=File:Navstar-2.jpg&amp;action=edit&amp;redlink=1" class="new" title="File:Navstar-2.jpg (page does not exist)">Navstar-2.jpg</a>: NASA</li>
<li><a href="//commons.wikimedia.org/wiki/File:Good_gdop_screen.svg" title="File:Good gdop screen.svg">Good_gdop_screen.svg</a>: <a href="//commons.wikimedia.org/wiki/User:Javiersanp" title="User:Javiersanp">Javiersanp</a></li>
<li>derivative work: <a href="//commons.wikimedia.org/wiki/User:Javiersanp" title="User:Javiersanp">Javiersanp</a> (<a href="//commons.wikimedia.org/wiki/User_talk:Javiersanp" title="User talk:Javiersanp"><span class="signature-talk">talk</span></a>)</li></ul>
<ul><li><a href="//commons.wikimedia.org/wiki/File:Clear_sky.JPG" title="File:Clear sky.JPG">Clear_sky.JPG</a></li>
<li><a href="//commons.wikimedia.org/wiki/File:Garmin_eTrex_Legend_C_in_hand.jpg" title="File:Garmin eTrex Legend C in hand.jpg">Garmin_eTrex_Legend_C_in_hand.jpg</a></li>
<li><a href="//commons.wikimedia.org/w/index.php?title=File:Navstar-2.jpg&amp;action=edit&amp;redlink=1" class="new" title="File:Navstar-2.jpg (page does not exist)">Navstar-2.jpg</a></li>
<li><a href="//commons.wikimedia.org/wiki/File:Good_gdop_screen.svg" title="File:Good gdop screen.svg">Good_gdop_screen.svg</a></li></ul>