<div dir="ltr"><br><span style="font-size:11pt;line-height:115%;font-family:"Calibri","sans-serif""><span style="font-size:11pt;line-height:115%;font-family:"Calibri","sans-serif"">Fetched “CurRnxN.nav” from <a href="ftp://ftp.trimble.com/pub/eph/and">ftp://ftp.trimble.com/pub/eph/and</a> had a look at the
raw data. The .nav data file is formatted as <span style>Receiver Independent Exchange Format</span> (<b style>RINEX</b>) 2.10 and contains GPS navigation methods.  <span style></span></span><br><br>SV
accuracy is defined in Broadcast Orbit Record 6 and this value is used as the
URA at line 1084 of rrlpserver.erl.<br></span><br><span style="font-size:11pt;line-height:115%;font-family:"Calibri","sans-serif"">

</span><p><span style="font-size:11pt;font-family:"Calibri","sans-serif";background:none repeat scroll 0% 0% yellow">The problem seems to be that SV accuracy in meters is being used as the
URA <u>index</u>. <span style> </span></span></p>

<p><span style="font-size:11pt;font-family:"Calibri","sans-serif"">The
confusion arises due to differences between the Receiver Independent Exchange
Format</span><span style="font-size:11pt;font-family:"Calibri","sans-serif""> (<b style>RINEX</b>) 2.10 format and Interface
Specification IS-GPS-200 (<a href="http://www.gps.gov/technical/icwg/">http://www.gps.gov/technical/icwg/</a>).
IS-GPS-200 section 20.3.3.3.1.3 states: ”</span><span style="font-size:11pt;font-family:"Calibri","sans-serif"">SV Accuracy - Bits 13 through 16 of
word three shall give the URA index of the SV. The URA index (N) is an integer
in the range of 0 through 15.”</span><span style="font-size:11pt;font-family:"Calibri","sans-serif";background:none repeat scroll 0% 0% yellow"></span></p>

<p><span style="font-size:11pt;font-family:"Calibri","sans-serif";background:none repeat scroll 0% 0% yellow">Hence I think the RRLP server needs to be <span style> </span>modified to support RINEX and specifically to
add a mapping from SV accuracy to URA index like in the code example here:</span><span style="font-size:11pt;font-family:"Calibri","sans-serif""></span></p>

<p><span style="font-size:11pt;font-family:"Calibri","sans-serif""><a href="http://www.gpstk.org/doxygen/GPS__URA_8hpp-source.html#l00109">http://www.gpstk.org/doxygen/GPS__URA_8hpp-source.html#l00109</a></span></p>


<p><span style="font-size:11pt;font-family:"Calibri","sans-serif"">For now I changed line 1084 in rrlpserver.erl
<span style> </span>to assume a URA index of 6 e.g. SV
accuracy in the range 13.65 – 24 meters: </span></p>

<p><span style="font-size:11pt;font-family:"Calibri","sans-serif"">stuff("ephemURA",
nmth(7,1,Tokens), AdjustTable),</span></p>

<p><span style="font-size:11pt;font-family:"Calibri","sans-serif"">Change to:</span></p>

<p><span style="font-size:11pt;font-family:"Calibri","sans-serif"">stuff("ephemURA", <span style="background:none repeat scroll 0% 0% yellow">“6”</span> , AdjustTable),</span></p>

<span style="font-size:11pt;line-height:115%;font-family:"Calibri","sans-serif"">Can any Erlang programmers help fix this?<br></span><div><span style="font-size:11pt;line-height:115%;font-family:"Calibri","sans-serif""><br>
</span></div></div>