cavern — process raw survey data
cavern [options] survex data file
Cavern is the Survex data processing engine.
If multiple survey data files are listed on the command line, they are
processed in order from left to right. Settings are reset to their
defaults before processing each file.
You can get cavern to display the percentage progress through
the current file. As of Survex 0.90 this is disabled by
default, but you can enable it if you want. Because the
value given is for the current file, the values jump around
for a multi-file survey project. Also note that displaying
this information slows down processing a little.
Sets location for output files.
Only show a brief summary (--quiet --quiet or -qq will
display warnings and errors only).
do not create .err file.
turn warnings into errors.
--log Send screen output to a .log file.
Cavern reads in text files containing the survey data .svx) and outputs
two files, with the extensions .3d and .err. By default these files
are put in the current directory, with the same base filename as the
first .svx file read, but a different extension. You can change the
directory and/or base filename using the --output command line option.
E.g. if you process the data file entrance.svx with the command cavern
entrance entrance.3d and entrance.err will be created.
Cavern also gives a range of statistics at the end of a successful run:
· The highest and lowest stations and the height difference between
· The total length of the survey (before and after adjustment).
This total excludes survey legs flagged as SURFACE, DUPLICATE, or
· The number of stations and legs. Note that a *EQUATE is counted
as a leg in this statistic.
· The East-West and North-South ranges, and the North-most, South-
most, East-most, and West-most stations.
· The number of each size of node in the network (where size is
number of connections to a station) i.e. a one node is the end of
a dead-end traverse, a two-node is a typical station in the
middle of a traverse, a three-node is a T-junction etc.
· How long the processing took and how much CPU time was used.
.3d - data describing the loop-closed centre line
This file contains details of the stations and legs, and any flags
associated with them.
.err - loop closure statistics (%age errors, etc)
This file contains statistics about each traverse in the survey which
is part of a loop. It includes various statistics for each traverse,
such as the percentage error per leg. You should study this
information to determine if any parts of the survey are of lower
quality or contain gross errors.
There are a number of error messages that you may get when processing
data. Most of these are self explanatory, and will be caused by such
problems as typing mistakes, or by your survey data not being attached
to fixed points (in this situation, Survex will list some of the
stations that are not connected).
Along with the error message, the filename and line number of the
offending line will be printed (or the filename for errors such as
‘file not found’). The format of the filename and line number is that
used by gcc, so if your editor can parse errors from gcc, you should be
able to set it to allow you to jump to the file and line of each error.
Cavern will stop after more than 50 errors. This usually indicates
something like the incorrect data order being specified. Deluging the
user with error messages makes the actual problem less clear.
3dtopos(1), aven(1), cad3d(1), diffpos(1), extend(1), sorterr(1),