Ubuntu Manpage: caveconverter - convert cave survey data between formats

Provided by: caveconverter_0~20170114-6_all

NAME

       caveconverter - convert cave survey data between formats

SYNOPSIS

       caveconverter infile outfile in_format out_format [ lrud ]

DESCRIPTION

       caveconverter  is  a program for converting cave survey data from one format into another.
       It can read and write a variety of cave survey data file formats,  translating  the  data,
       and can also generate LRUD info from splay shots.

   Formats read:
       Survex -  Supports  normal,  diving  and  nosurvey format data (in any supported units and
                 field orders). Multi-file  reading  now  supported  (but  ignores  FIX  commands
                 currently) (.svx files)

       Compass - The data file format generated by the Compass cave survey software. (.dat files)

       PocketTopo text export -
                 Text export option in PocketTopo menu. (.txt files)

       DXF -     Reads Lines and Polylines as survey centreline data. (.dxf files)

   Formats written:
       Toporobot -
              For using to import data into PocketTopo software on a PDA. (.text files)

       Survex -
              Converts  to metric units currently, and entire series will be output in same field
              order (matching order of fields from last leg per series from  input  file).  (.svx
              files)

OPTIONS

       The format codes are:
       c - Compass
       d - DXF
       p - PocketTopo text export
       s - Survex
       t - Toporobot

       lrud - Adding the lrud flag to the end of the command causes LRUD (left rght up down) info
              to be generated from splay data

CONVERSION DETAILS

Converting from DXF files to survex shows how editable survey data can be regenerated from
Survex .3d files via the Convert to DXF option provided by Survex

This is also how you can generate a DXF file to convert to Toporobot using caveconverter,
enabling existing cave surveys to be imported into PocketTopo regardless of the original
Survex format data. So if your Survex file is not readable by caveconverter (e.g. because
it contains some unimplemented feature) then you can still process it using Survex to
generate a 3d file and convert that to DXF using Survex. Then convert it to Toporobot
format using caveconverter and import that file into PocketTopo. This enables existing
surveys to be loaded into PocketTopo so that new data can be tied into the known cave on
surveying trips.

Converting Survex data to Toporobot will cause all the survey station numbers and series
names to get regenerated, unfortunately. This is because Toporobot format requires survey
series to consist only of linear chains of survey stations. Junctions are not allowed in
series. This means that data from other formats cannot be simply converted, so all
stations are renumbered and reorganised into new numbered series to conform to this
constraint of the Toporobot format.

If you find files that give errors on conversion, send them to me (Footleg). I can be
contacted by email: drfootleg [at] gmail.com

While caveconverter can regenerate survey data files from DXF files generated from Survex
.3d files, you will not get back the complete original data. What you do get is the
equivalent calculated survey leg data (tape, compass, clino) for the positions of the
stations in the DXF file. So any loop closure corrections and instrument calibrations will
have already been applied to the data. This feature is really intended as a way to recover
some sort of workable data when the original data has been lost and only the 3d files
remain. Some small rounding errors occur during the Conversion to DXF from the .3d file,
so the exact positions of survey stations and the cave length reported may differ by a few
cm compared to the original data. This is because in the DXF file, Survex has rounded all
station positions to the nearest 1cm.

SPLAY/LRUD conversion
The original approach to reading splay legs from PocketTopo files in caveconverter was to
treat them as just a way of measuring passage dimensions as Left, Right, Up, Down
measurements at each station. So when no more than four splays were found at a station the
code used their lengths as LRUD measurements and removed the splays from the data in the
process. This kept Survex models looking like they used to before we started measuring
lots of splays. But as my own surveying experience increased over recent years I realised
that splays are a much more useful tool than just a way to take LRUD measurements. With a
DistoX the splays can quickly and accurately be fired from stations to pick out key
features and passage shapes at corners and in chambers. These splays aid drawing the
correct position of walls, ceiling and floor as well as passage features. They are
valuable data which should not be replaced with LRUD passage dimension data. LRUD data
still has value. A number of file formats support LRUD data to represent the position of
passage walls at each station, and 3D model generation uses this data. But the splays
should still be kept when generating LRUD data from them. The latest Aven viewer (part of
the Survex 1.2.7 release) and the Loch Viewer (part of Therion) now both allow splay legs
to be shown or hidden. So it is possible to view centreline only models without actually
removing the splays from the data.

So this latest version of caveconverter no longer removes splay legs used to generate LRUD
measurements. The LRUD generation code has also been completely rewritten and made part of
the core data model rather than an operation done during reading of PocketTopo files. This
means it is now possible to generate LRUD data from splays in any data file which can be
read. Unfortunately for those of you who used caveconverter in the past to convert
PocketTopo data to Survex format it will have removed a lot of the splays, so you will
want to convert from the original PocketTopo exported text files again with this version.
The LRUD generation does a much better job of selecting the best splay to determine a
passage dimension measurement from in this version of the code. The splay which
contributes the greatest distance of the wall/ceiling/floor from the station is used to
calculate the distance to the wall. Previous versions of the code just used the total
length of the best splay, rather than the distance in the direction of the LRUD
measurement being set. This was flawed and splays almost parallel to a survey leg could
generate much larger passage dimension measurements than was appropriate. Now trigonometry
is used to determine the appropriate distance in the direction of the passage dimension,
and the direction for the left and right measurements is calculated from the best matching
previous leg as well as the onward leg from the station.

The conversion of Survex data (containing splays) to Toporobot format in order to import
existing survey data into PocketTopo to extend off on new survey trips can now generate
and output LRUD data too. PocketTopo will display this data as splays orthogonal to the
direction of the survey legs to indicate passage width and height.

Another bugbear of previous versions of caveconverter was that LRUD data was output in
Survex files as one continuous block of stations with LRUD data, regardless of how the
stations were connected by survey legs. This has now been fixed so the survey legs in each
series are used to determine the grouping of passage data stations into blocks of
connected stations.

Convert existing survey data for loading into PocketTopo on a PDA
To load an existing survey into PocketTopo on a PDA in order to extend a survey with
reference to the existing data for the cave, you can convert to Toporobot format using the
caveconverter. Then import the Toporobot file into PocketTopo on the PDA. The input survey
data could be read from a Compass file, or a Survex file. Where a Survex file contains
formats which caveconverter is not yet able to read, you can instead process the data in
Survex to generate a .3d file, and then use Survex convert this to a DXF file (right-click
on a .3d file to select this option from the pop-up menu in Windows Explorer). Cave
Converter can then read this DXF file and generate a Toporobot file. Converting survey
data to Toporobot will unfortunately cause all the survey station numbers and series names
to be changed. This is because Toporobot format requires survey series to consist only of
linear chains of survey stations. Junctions are not allowed in these chains, so junctions
in the cave require a new chain to be started. This means that data from other formats
cannot be simply converted, so all stations are renumbered and organised into new numbered
series to conform to these constraints of the Toporobot format.

Regenerate Editable Survey Data from DXF or Survex 3D Files
Sometimes the survey data for a project from the past has been lost, and all that remains
is some processed output. caveconverter can regenerate editable survey data from DXF files
where the survey centreline is represented by straight line objects or polylines. This
includes DXF files generated by Survex from Survex .3d files. The Aven viewer in Survex
can export a DXF file from a cave model, or right-click on a .3d file in Windows Explorer
to select the Convert to DXF option from the pop-up menu.

Survex to Survex with LRUD generation
caveconverter can create LRUD passage data blocks for Survex files containing splays. Just
read and write Survex format, using the LRUD option. The Survex file reader in
caveconverter does not currently read existing passage data blocks. So be aware that
existing passage data blocks will be removed if a Survex file is read in and written out
again. However if the Survex file contains splays and the lrud option is specified on the
command line (or the Generate LRUD option is run after loading the data into the windowed
application) then new passage data blocks will be generated from the splays and replace
any previously present passage data blocks in the output file.

Specifying Character Set Encoding
If you are reading in data files which contain extended character set symbols (e.g.
accented characters or non-punctuation symbol characters) then caveconverter will assume
these files are using UTF-8 encoding by default. To specify a different encoding in the
Windows application you can edit the app.properties file. (This file is written to the
same folder as the CaveConverterGUI.jar file when you close the application. So run the
application once and close it, then you should find the app.properties file which will
contain the line 'character.set=UTF8'. Edit this line to specify an alternative character
set encoding if you are not using UTF-8. See the command line reference html page for more
details on alternative character set codes, and also how to specify them for command line
conversions.

EXAMPLES

       To convert existing Survex data  into  Toporobot  format  so  you  can  import  it  in  to
       PocketTopo:
       caveconverter survexfile.svx output.text s t

       To  convert  data  exported  from  PocketTopo into Survex format, including LRUD info from
       splays:
       caveconverter pdaexport.txt survexfile.svx p s lrud

       To convert data from  DXF  format  into  Toporobot  format  so  you  can  import  it  into
       PocketTopo:
       caveconverter datafile.dxf toporobotfileout.text d t

       To convert data from DXF format into Survex format:
       caveconverter datafile.dxf survexfile.svx d s

BUGS

       Survex output re-uses 'to station' numbers for splay legs if all splays from a station are
       not together in the file. So if a set of splay legs occur in a series of legs  within  the
       same  begin/end  block  followed by a leg from a different station, and then another splay
       leg from the original station is found further  down  the  block  then  the  'to  station'
       numbering will start from 'a' again. So you can for example get two splays from station 10
       with to station names of '10a' in the file. The file can be processed but  shows  a  large
       loop closure error for the splays as it equates the two 10a stations at the end of the two
       splays as being the same point.

AUTHOR

       Paul 'Footleg' Fretwell (drfootleg@gmail.com)