/usr/share/doc/survex/manual/genhowto.htm

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><H1
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><A
NAME="AEN1539"
>General: How do I?</A
></H1
><DIV
CLASS="SECT2"
><H2
CLASS="SECT2"
><A
NAME="AEN1541"
>Create a new survey</A
></H2
><P
>You simply create a text file containing the relevant survey data,
using a text editor, and save it with a suitable name with a <TT
CLASS="FILENAME"
>.svx</TT
>
extension. The
easiest way is to look at some of the example data and use that
as a template. Nearly all surveys will need a bit of basic info
as well as the survey data itself: e.g. the date (*date), comments
about where, what cave, a name for the survey (using *begin and *end),
instrument error corrections etc. Here is a typical survey file:</P
><P
>All the lines starting with ';' are comments, which are ignored
by <SPAN
CLASS="APPLICATION"
>Survex</SPAN
>. You can also see the use of 'DOWN' for plumbs, and
*calibrate tape for dealing with a tape length error (in this case
the end of the tape had fallen off so measurements were made from the
20cm point).</P
><TABLE
BORDER="0"
BGCOLOR="#E0E0E0"
WIDTH="100%"
><TR
><TD
><PRE
CLASS="PROGRAMLISTING"
>*equate chaos.1 triassic.pt3.8
*equate chaos.2 triassic.pt3.9

*begin chaos
*title "Bottomless Pit of Eternal Chaos to Redemption pitch"
*date 1996.07.11
*team "Nick Proctor" compass clino tape
*team "Anthony Day" notes pictures tape
*instrument compass "CUCC 2"
*instrument clino "CUCC 2"
;Calibration: Cairn-Rock 071 072 071,  -22 -22 -22
;       Rock-Cairn 252 251 252,  +21 +21 +21
;Calibration at 161d entrance from cairn nr entrance to
;prominent rock edge lower down. This is different from
;calibration used for thighs survey of 5 July 1996

*export 1 2

;Tape is 20cm too short
*calibrate tape +0.2

1 2 9.48 208 +08
2 3 9.30 179 -23
3 4 2.17 057 +09
5 4 10.13 263 +78
5 6 2.10 171 -73
7 6 7.93 291 +75
*begin
*calibrate tape 0
8 7 35.64 262 +86 ;true length measured for this leg
*end
8 9 24.90 - DOWN
10 9 8.61 031 -43
10 11 2.53 008 -34
11 12 2.70 286 -20
13 12 5.36 135 +23
14 13 1.52 119 -12
15 14 2.00 036 +13
16 15 2.10 103 +12
17 16 1.40 068 -07
17 18 1.53 285 -42
19 18 5.20 057 -36
19 20 2.41 161 -67
20 21 27.47 - DOWN
21 22 9.30 192 -29
*end chaos</PRE
></TD
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></DIV
><DIV
CLASS="SECT2"
><H2
CLASS="SECT2"
><A
NAME="AEN1548"
>Join surveys together</A
></H2
><P
>Once you have more than one survey you need to specify how they
link together. To do this use *export to make the stations to be
joined accessible in the enclosing survey, then *equate in the
enclosing survey to join them together.</P
></DIV
><DIV
CLASS="SECT2"
><H2
CLASS="SECT2"
><A
NAME="AEN1551"
>Organise my surveys</A
></H2
><P
>This is actually a large subject. There are many ways you can
organise your data using <SPAN
CLASS="APPLICATION"
>Survex</SPAN
>. Take a look at the example dataset
for some ideas of ways to go about it.</P
><DIV
CLASS="SECT3"
><H3
CLASS="SECT3"
><A
NAME="AEN1555"
>Fixed Points (Control Points)</A
></H3
><P
>The *fix command is used to specify fixed points (also know as control
points).  See the description of this command in the "Cavern Commands"
section of this manual.</P
></DIV
><DIV
CLASS="SECT3"
><H3
CLASS="SECT3"
><A
NAME="AEN1558"
>More than one survey per trip</A
></H3
><P
>Suppose you have two separate bits of surveying which were done on the
same trip.  So the calibration details, etc. are the same for both.  But you
want to give a different survey name to the two sections.  This is easily
achieved like so:</P
><TABLE
BORDER="0"
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><TR
><TD
><PRE
CLASS="PROGRAMLISTING"
>*begin
*calibrate compass 1.0
*calibrate clino 0.5
*begin altroute
; first survey
*end altroute
*begin faraway
; second survey
*end faraway
*end</PRE
></TD
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><DIV
CLASS="SECT2"
><H2
CLASS="SECT2"
><A
NAME="AEN1562"
>Add surface topography</A
></H2
><P
>Survex 1.2.18 added support for loading terrain data and rendering it as
a transparent surface.</P
><P
>We recommend using this new code in preference, but previously the simplest
approach was to generate a <TT
CLASS="FILENAME"
>.svx</TT
> file with the surface mesh
in and display it with the survey data.</P
><P
>It is possible to generate
a mesh or contours overlaying your area by various means.  NASA have made
1 arc-second (approximately 30m) terrain data available for the USA for
some years, with only 3 arc-second data available for other countries.
However, starting in 2014 they're gradually making 1 arc-second data
available for more countries.</P
><P
>If you want a better resolution that this, reading heights from the
contours on a map is one approach.  It's laborious, but feasible for
a small area.</P
><P
>Details of several methods are given in the BCRA Cave Surveying
Group magazine Compass Points issue 11, available online at
<A
HREF="http://www.chaos.org.uk/survex/cp/CP11/CPoint11.htm#Art_5"
TARGET="_top"
>http://www.chaos.org.uk/survex/cp/CP11/CPoint11.htm#Art_5</A
></P
><P
>If you're using another program to generate a <TT
CLASS="FILENAME"
>.svx</TT
> file for the surface
mesh, it's best to use the NOSURVEY data style.
Simply fix all the grid intersections at the correct
coordinates and height, and put legs between them using the NOSURVEY style.
Here's a grid of 4 squares and 9 intersections:</P
><TABLE
BORDER="0"
BGCOLOR="#E0E0E0"
WIDTH="100%"
><TR
><TD
><PRE
CLASS="PROGRAMLISTING"
>*fix 00 000 000 1070
*fix 01 000 100 1089
*fix 02 000 200 1093

*fix 10 100 000 1062
*fix 11 100 100 1080
*fix 12 100 200 1089

*fix 20 200 000 1050
*fix 21 200 100 1065
*fix 22 200 200 1077

*data nosurvey station

00
01
02

10
11
12

20
21
22

00
10
20

01
11
21

02
12
22</PRE
></TD
></TR
></TABLE
><P
>This is far simpler than trying to create fake tape/compass/clino legs of
the right length for each line in the mesh.  It's also very fast to process
with cavern.</P
></DIV
><DIV
CLASS="SECT2"
><H2
CLASS="SECT2"
><A
NAME="AEN1575"
>Overlay a grid</A
></H2
><P
>Aven is able to display a grid, but this functionality isn't currently
available in printouts.
You can achieve a similar effect for now by creating a <TT
CLASS="FILENAME"
>.svx</TT
> file
where the survey legs form a grid.</P
></DIV
><DIV
CLASS="SECT2"
><H2
CLASS="SECT2"
><A
NAME="AEN1579"
>Import data from other programs</A
></H2
><P
><SPAN
CLASS="APPLICATION"
>Survex</SPAN
> supports a number of features to help with importing
existing data. You can specify the ordering of items on a line using *Data
(see <SPAN
CLASS="APPLICATION"
>Survex</SPAN
> Keywords above), and you can specify the characters used
to mean different things using *Set (see <SPAN
CLASS="APPLICATION"
>Survex</SPAN
> Keywords above).</P
><P
>The Ignore and Ignoreall options to the *Data command are often
particularly useful, e.g. if you have a dataset with LRUD info or comments
on the ends of lines.</P
><DIV
CLASS="SECT3"
><H3
CLASS="SECT3"
><A
NAME="AEN1586"
>Changing Meanings of Characters</A
></H3
><P
>e.g. if you have some data with station names containing the 
characters '?' and '+' (which are not permitted in a name by default)
then the command:</P
><TABLE
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WIDTH="100%"
><TR
><TD
><PRE
CLASS="PROGRAMLISTING"
>*SET NAMES ?+</PRE
></TD
></TR
></TABLE
><P
>specifies that question marks and plus signs are permitted in station names.
A-Z, a-z, and 0-9 are always permitted. '_' and '-' are also permitted by
default, but aren't in this example.</P
><P
>If your data uses a comma ',' instead of a decimal point, then
you use</P
><TABLE
BORDER="0"
BGCOLOR="#E0E0E0"
WIDTH="100%"
><TR
><TD
><PRE
CLASS="PROGRAMLISTING"
>*SET DECIMAL ,</PRE
></TD
></TR
></TABLE
><P
>to specify that ',' is now the decimal separator instead of '.'.</P
></DIV
></DIV
><DIV
CLASS="SECT2"
><H2
CLASS="SECT2"
><A
NAME="AEN1594"
>Export data from <SPAN
CLASS="APPLICATION"
>Survex</SPAN
></A
></H2
><P
>See Rosetta Stal in the Related Tools section of the Survex web
site.  This is a utility written by Taco van Ieperen and Gary Petrie.
Note though that this only supports a subset of the svx format,
and only work on Microsoft Windows.  The Survex support is limited
and doesn't understand the more recently added commands.</P
></DIV
><DIV
CLASS="SECT2"
><H2
CLASS="SECT2"
><A
NAME="AEN1598"
>See errors and warnings that have gone off the screen</A
></H2
><P
>When you run <SPAN
CLASS="APPLICATION"
>Survex</SPAN
> it will process the specified survey data
files in order, reporting any warnings and errors.  If there are no
errors, the output files are written and various statistics about the
survey are displayed. If there are a lot of warnings or errors, they can
scroll off the screen and it's not always possible to scroll back to
read them.</P
><P
>The easiest way to see all the text is to use <B
CLASS="COMMAND"
>cavern
--log</B
> to redirect output to a <TT
CLASS="FILENAME"
>.log</TT
> file,
which you can then inspect with a text editor.</P
></DIV
><DIV
CLASS="SECT2"
><H2
CLASS="SECT2"
><A
NAME="AEN1605"
>Create an Extended Elevation</A
></H2
><P
>Use the Extend program. This takes <TT
CLASS="FILENAME"
>.3d</TT
> files and
'flattens' them.  See 'Extend' for details.</P
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survex 1.2.26-1 / usr / share / doc / survex / manual / genhowto.htm
