CUCC Expedition Handbook - New Survex file

Creating a new survex file

Great, I have discovered a new cave...

If you have not come to this page from the sequence starting at Starting a New Cave" then go and read that first.

This page outlines step 3 of the survey production process. Each step is documented separately.
1 - 2 - 3 - 4 - 5 - 6 - 7 - 8


In principle you do not need any software other than a text editor to create a survex file. So you do not need to have installed survex on your laptop at this point.

Two ways to type in survex data

Typical raw survex data - 'bidet' in Steinbrückenhöhle, Martin Green 14/8/2000

Typing in the survey data in survex format

The survey data typed up must include all the notes, including station details and passage names. Make a backup copy to another machine or USB stick as soon as you have typed it in. New users will be using the expo laptop to create the .svx file and you will put it in the folder

and tell someone nerdy when you have finished and they will ensure that it is saved, committed, and pushed appropriately to the :loser: repo.

If you have several parts of the cave surveyed on one trip, create several distinct .svx files.

Once you have created the .svx file you will run survex to check that your format is correct without typos and to generate a centre line. Then you will print the survey line, manually transcribe your sketches from the wallet notes onto that paper, scan it again and then use that scanned image to digitise passage layout into tunnel or therion.

[Nerds: survex cave data belongs in the repository :loser: so e.g. :loser:/caves-1623/264/mongolrally.svx". We are assuming that normal users have never worked with an distributed version control system at this point which is why we are only telling them to use the expo laptop.]

Entering the QM data

QMs are the unexplored leads, they are Question Marks because we don't know where they go to. There is a specific format for recording them in survex files.

Read this separate description about entering the QM data into a survex file.

Entering the cave description in the survex file

The last part of the survex file is a description of the passage surveyed. Remember that this is intended to be read by people who have not been to that bit of the cave themselves ;------------
;Cave description ;(leave commented-out)
; See 2017 description for details of GSH up to the 'p50'. Briefly, on the way to couldashouldawoulda a 22 m entrance crawl from the surface leads to a climb down and a junction. Left leads to easy c rawling passage for a short distance, then another junction where traversing over a shallow hole and down a stooping-height sandy passage to a sharp left turn and a sandy, easy 'squeeze' leading to a straighforward p10.
[from couldashouldawoulda_to_bathdodgersbypass.svx]

Note that the description is often written as one long line. Use the word-wrap capability in your editor to make it easier for yourself.

Using the direct online system

This is where you type up the hand-scrawled notes directly into a a web browser, creating a new online survex file automatically in the right place on the online system.

Having confirmed the right name to use for your cave, including whether it is in area 1623 or 1626, e.g.

open a web browser on the equivalent page{area}/{cave}/{surveytripid}.svx
where {area} will be 1623 or 1626, and for a new discovery, {cave} will be something like 2050-BH-01 if it is the third cave disovered by Dr. Bunsen Honeydew on the 2050 expo, e.g.
and a survex-file editing page will open, pre-populated with an example template for survex data, most of which you will delete and replace. Edit this template and type in your own data.

You can save your work by pressing the "Save this edited svx file" button, but it will refuse to save until you have hand-edited out all the template material in [square brackets].

As you edit it, you can press the "Differences between edited and saved versions of this file" and the differences which comprise your recent typing will be listed below the edit window.

Before you finish typing, use the third button "Run 'cavern' on this file".
- If you haven't yet removed all the [square brackets] stuff, nothing will happen except a message

below the edit window.
- If you try to save before editing out the [square brackets] stuff then you wil get a message
  Error: remove all []s from the text. They are only template guidance.
below the editing window.
- But if you have done all that, then survex will process your new survex file and tell you interesting things about your survey data below the editing window. ('cavern' is the survex engine which we use to process survex files.)

You may see a number of error messages below the editing window: read them and understand them. If you don't understand them, ask someone.

So using the online system gives you a very, very easy way of syntax-checking your data entry and typing up your notes.

The output you get from 'cavern' will look like this (yes this really does take less than 0.01s):

    Survey contains 21 survey stations, joined by 23 legs.
    There are 3 loops.
    Total length of survey legs =  305.80m ( 305.79m adjusted)
    Total plan length of survey legs =  253.09m
    Total vertical length of survey legs =  125.24m
    Vertical range = 44.74m (from galactica.1 at 0.35m to galactica.20 at -44.39m)
    North-South range = 99.31m (from galactica.19 at 28.14m to galactica.12 at -71.17m)
    East-West range = 53.27m (from galactica.1 at 1.12m to galactica.9 at -52.15m)
       3 1-nodes.
      13 2-nodes.
       3 3-nodes.
       2 4-nodes.
    CPU time used  0.00s

Folders and subfolders

If you have a complex cave like 204 or 161 with many separate exploration zones then you can put subfolder names in the URL bar e.g.

and the intermediate directories will be created on the server if they don't already exist. This is in addition to the directory name which is also the name of your new cave being created automatically.

Back to the previous page in this sequence Creating a new survey wallet.
Now go the the next page in this sequence Drawing up your survey.