<html><head><meta http-equiv="content-type" content="text/html; charset=utf-8"></head><body dir="auto"><div>Dual frequency receivers could solve this problem. You need both the rover and the base station receivers to be dual frequency.<br><br>Kind regards,<div>Yanqing</div></div><div><br>On 18 Sep 2014, at 03:02, "Sean Hyde" <<a href="mailto:sean.a.hyde@gmail.com">sean.a.hyde@gmail.com</a>> wrote:<br><br></div><blockquote type="cite"><div><meta http-equiv="Content-Type" content="text/html; charset=us-ascii"><meta name="Generator" content="Microsoft Word 15 (filtered medium)"><style><!--
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</o:shapelayout></xml><![endif]--><div class="WordSection1"><p class="MsoNormal">Thanks for the responses! I apologize for breaking the thread, but I had turned on Digests by accident and couldn’t figure out how to reply to individual messages.<o:p></o:p></p><p class="MsoNormal"><o:p> </o:p></p><pre>“<span style="color:black">I'm not sure what receivers you are using, but if it's this one: <o:p></o:p></span></pre><pre><span style="color:black"><a href="http://www.nvs-gnss.com/products/receivers/item/2-nv08c-csm.html">http://www.nvs-gnss.com/products/receivers/item/2-nv08c-csm.html</a> it seems <o:p></o:p></span></pre><pre><span style="color:black">to be L1 only, not L1+L2. The antenna you are using covers 1574-1610 MHz, <o:p></o:p></span></pre><pre><span style="color:black">so while multi-system (GPS/Glonass) it is also L1 only. The GPS L2 <o:p></o:p></span></pre><pre><span style="color:black">frequency is quite a bit lower, at 1227.6 MHz.<o:p></o:p></span></pre><pre><span style="color:black"><a href="http://en.wikipedia.org/wiki/GPS_signals#Frequencies_used_by_GPS">http://en.wikipedia.org/wiki/GPS_signals#Frequencies_used_by_GPS</a><o:p></o:p></span></pre><pre><span style="color:black"><o:p> </o:p></span></pre><pre><span style="color:black">As far as I know, GPS L1+L2 receivers start around $750 used (eg. Trimble <o:p></o:p></span></pre><pre><span style="color:black">4000ssi on ebay) and much more new.<o:p></o:p></span></pre><p class="MsoNormal">“<o:p></o:p></p><p class="MsoNormal"><o:p> </o:p></p><p class="MsoNormal">Hi John. I had completely overlooked the fact that the NV08C couldn’t utilize L2 as I had read a lot of information about using it in RTK setups. I’m rather new to GPS. My understanding is that without L2 I will not be able to get rid of ionospheric delay, which will increase error. Could this be why my system isn’t performing as I hoped? Can I get away with using an L1+L2 receiver on the Base Station and not on the Rover?<o:p></o:p></p><p class="MsoNormal"><o:p> </o:p></p><p class="MsoNormal"><o:p> </o:p></p><pre>“<span style="color:black">Did you try with simultaneous mode of ambiguity resolution and use a smaller min ratio to fix ambiguity, such as 2 or 1.5?<o:p></o:p></span></pre><pre><span style="color:black"><o:p> </o:p></span></pre><pre><span style="color:black">Kind regards,<o:p></o:p></span></pre><pre><span style="color:black">Yanqing<o:p></o:p></span></pre><p class="MsoNormal">“<o:p></o:p></p><p class="MsoNormal"><o:p> </o:p></p><p class="MsoNormal">Hello Yanging. I tried instantaneous mode and it seemed much worse. My Float solutions oscillated by several meters (instead of a tens of centimeters with a drift) and I couldn’t get a Fix. I tried reducing the ratio in the other modes. Although that got me a fix more easily, I was concerned that it wasn’t accurate, as it was not repeatable. <o:p></o:p></p><p class="MsoNormal"><o:p> </o:p></p><p class="MsoNormal">-Sean<o:p></o:p></p></div></div></blockquote><blockquote type="cite"><div><span>_______________________________________________</span><br><span>This message is sent to you from <a href="mailto:FOSS-GPS@lists.osgeo.org">FOSS-GPS@lists.osgeo.org</a> mailing list.</span><br><span>Visit <a href="http://lists.osgeo.org/mailman/listinfo/foss-gps">http://lists.osgeo.org/mailman/listinfo/foss-gps</a> to manage your subscription</span><br><span>For more information, check <a href="http://wiki.osgeo.org/wiki/FOSS-GPS">http://wiki.osgeo.org/wiki/FOSS-GPS</a></span></div></blockquote></body></html>