<html xmlns:v="urn:schemas-microsoft-com:vml" xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns:m="http://schemas.microsoft.com/office/2004/12/omml" xmlns="http://www.w3.org/TR/REC-html40"><head><meta http-equiv=Content-Type content="text/html; charset=utf-8"><meta name=Generator content="Microsoft Word 15 (filtered medium)"><!--[if !mso]><style>v\:* {behavior:url(#default#VML);}
o\:* {behavior:url(#default#VML);}
w\:* {behavior:url(#default#VML);}
.shape {behavior:url(#default#VML);}
</style><![endif]--><style><!--
/* Font Definitions */
@font-face
{font-family:"Cambria Math";
panose-1:2 4 5 3 5 4 6 3 2 4;}
@font-face
{font-family:Calibri;
panose-1:2 15 5 2 2 2 4 3 2 4;}
/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
{margin:0cm;
margin-bottom:.0001pt;
font-size:11.0pt;
font-family:"Calibri",sans-serif;}
a:link, span.MsoHyperlink
{mso-style-priority:99;
color:#0563C1;
text-decoration:underline;}
a:visited, span.MsoHyperlinkFollowed
{mso-style-priority:99;
color:#954F72;
text-decoration:underline;}
p.MsoPlainText, li.MsoPlainText, div.MsoPlainText
{mso-style-priority:99;
mso-style-link:"Plain Text Char";
margin:0cm;
margin-bottom:.0001pt;
font-size:11.0pt;
font-family:"Calibri",sans-serif;}
span.PlainTextChar
{mso-style-name:"Plain Text Char";
mso-style-priority:99;
mso-style-link:"Plain Text";
font-family:"Calibri",sans-serif;}
span.EmailStyle20
{mso-style-type:personal-compose;
font-family:"Calibri",sans-serif;
color:windowtext;}
.MsoChpDefault
{mso-style-type:export-only;
font-family:"Calibri",sans-serif;}
@page WordSection1
{size:612.0pt 792.0pt;
margin:72.0pt 72.0pt 72.0pt 72.0pt;}
div.WordSection1
{page:WordSection1;}
--></style><!--[if gte mso 9]><xml>
<o:shapedefaults v:ext="edit" spidmax="1026" />
</xml><![endif]--><!--[if gte mso 9]><xml>
<o:shapelayout v:ext="edit">
<o:idmap v:ext="edit" data="1" />
</o:shapelayout></xml><![endif]--></head><body lang=EN-NZ link="#0563C1" vlink="#954F72"><div class=WordSection1><p class=MsoPlainText>Here is what happens with a real project that I did a year ago.<o:p></o:p></p><p class=MsoPlainText>As far as extended elevations go, it is a well-behaved project, that was built incrementally, starting with survey 1, then 2 etc.<o:p></o:p></p><p class=MsoPlainText>While the extended network behaves well, the log does not do so well. Here is a small sample.<o:p></o:p></p><p class=MsoPlainText>Curiously the extend log shows it starting in the middle of the survey sequence (it goes to survey 6 or 7) at a random entrance. There is no start 4.24 in the data, only a start 1.0!<o:p></o:p></p><p class=MsoPlainText><o:p> </o:p></p><p class=MsoPlainText>And yet…<o:p></o:p></p><p class=MsoPlainText><o:p> </o:p></p><p class=MsoPlainText><img width=178 height=544 style='width:1.8541in;height:5.6666in' id="Picture_x0020_2" src="cid:image001.png@01D5AAF3.109AC150"><span style='color:black'><img width=640 height=464 style='width:6.6666in;height:4.8333in' id="Picture_x0020_1" src="cid:image004.png@01D5AAEF.A143F9F0"></span><span style='color:black'><o:p></o:p></span></p><p class=MsoPlainText><span style='color:black'><o:p> </o:p></span></p><p class=MsoPlainText><span style='color:black'>Two more things:<o:p></o:p></span></p><p class=MsoPlainText><span style='color:black'>The sequence from 4.20 to 4.19 all the way to 4.15 is extending right, but the log says it is left.<o:p></o:p></span></p><p class=MsoPlainText><span style='color:black'>I deduce that the sequence then steps back along the same network until it is time to extend along a new branch. That is what the BACK refers to (nice).<o:p></o:p></span></p><p class=MsoPlainText><span style='color:black'><o:p> </o:p></span></p><p class=MsoPlainText><span style='color:black'>Here is what the specified extended network that generates both of the images above look like.<o:p></o:p></span></p><p class=MsoPlainText><span style='color:black'><img width=250 height=523 style='width:2.6041in;height:5.4479in' id="Picture_x0020_4" src="cid:image005.png@01D5AAF3.109AC150"></span><span style='color:black'><o:p></o:p></span></p><p class=MsoPlainText><span style='color:black'><o:p> </o:p></span></p><p class=MsoPlainText><span style='color:black'>and much further down the table it gets to the bit of passage in the image above…<o:p></o:p></span></p><p class=MsoPlainText><span style='color:black'><o:p> </o:p></span></p><p class=MsoPlainText><span style='color:black'><img width=271 height=543 style='width:2.8229in;height:5.6562in' id="Picture_x0020_3" src="cid:image006.png@01D5AAF3.109AC150"></span><span style='color:black'><o:p></o:p></span></p><p class=MsoPlainText><span style='color:black'><o:p> </o:p></span></p><p class=MsoPlainText><span style='color:black'>So, the extend log, although following a credible path along the survey network, has some directional errors, and is nothing like the specified path.<o:p></o:p></span></p><p class=MsoPlainText><span style='color:black'><o:p> </o:p></span></p><p class=MsoPlainText><span style='color:black'>Curiously, this log, like the logs for some other projects of mine, end with some apparently random non-existent STARTs and stations that don’t necessarily exist, like -@1 in the sequence below.<o:p></o:p></span></p><p class=MsoPlainText><span style='color:black'><o:p> </o:p></span></p><p class=MsoPlainText><span style='color:black'><img width=204 height=290 style='width:2.125in;height:3.0208in' id="Picture_x0020_5" src="cid:image013.png@01D5AAF3.109AC150"></span><span style='color:black'><o:p></o:p></span></p><p class=MsoPlainText><span style='color:black'><o:p> </o:p></span></p><p class=MsoPlainText><span style='color:black'>So, this feature has real promise, but I wonder if there is a bug, and now I am really interested how the extend specifications and logs compare in Tarquin’s short oxbow examples.<o:p></o:p></span></p><p class=MsoPlainText><span style='color:black'><o:p> </o:p></span></p><p class=MsoPlainText><span style='color:black'>Bruce<o:p></o:p></span></p></div></body></html>