surveying
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jarvist
New member
Oh wow! Big topic.
The Wikipedia article is pretty good on this:
http://en.wikipedia.org/wiki/Cave_survey
From a practical point of view you are taking measurements with Compass, Clinometer and Tape Measure (or Laser Rangefinder) between a series of stations. Stations are mostly temporary reference points just chosen for their line of sight to the next station, though at the end of a survey or at a notable junction, you sometimes install 'permanent survey stations' as points of reference. In these enlightened days you should certainly avoid the temptation to mark the cave wall by scratching it or otherwise to help your partner locate the station.
Each of these measurements defines a survey shot (or leg), which together make the centreline going through the cave.
You also record information about the dimensions & nature of the cave passage around this arbitrary centreline (typically left-right-up-down data around the station, and ideally a cross section sketch).
Back on the surface, your meticulous shot data, notes & sketches are typically entered into a dedicated survey computer program such as Survex, which does all the necessary trigonometry and trendy loop closures to give you a line drawing in Plan & Elevation, which you then supplement with your data about the nature of the cave to produce the eventual drawn survey.
The BCRA publication 'Cave Surveying' by Anthony J Day is a really good reference, and useful for symbols page alone. Apparently you can get it for the cost of ?1 postage direct from the BCRA...
http://bcra.org.uk/pub/cs/index.html?j=11
In terms of actually doing this 'for real' you'll need a set of instruments, such as the Suunto KB-14 Compass / PM-5 Clino. These are expensive. Your best bet would be trying to borrow a set of instruments, most club's sets sit gathering dust 99% of the time.
You also need a fibre tape measure, and a 'survey book' to put it all down in. 'Open Frame' tape measures are more mud resistant and reliable.
Though bringing back 'publication grade' data will require professional instruments, you can learn to survey with more basic gear - just a sighting compass and an improvised clino with a protractor + weight on a thread, perhaps? Learning to survey is perhaps 5% reading the instruments, 95% writing up your book nicely, not making blunders, miscounting stations, placing stations in good locations, communicating with your survey partner etc.
A good test of your skills is to purposefully form loops in your surveys, and see what the closure error is.
I put together some PDFs with survey books in both the 'Arrows' and 'From-To' form a few years ago. They print well with a laser printer onto A4 paper, for guillotining and rebinding as survey books:
http://union.ic.ac.uk/rcc/caving/FILES/survey_book_arrows_2010_name_survey.pdf
http://union.ic.ac.uk/rcc/caving/FILES/survey_book_fromto.pdf
And graph paper for the flipside for scale sketches:
http://union.ic.ac.uk/rcc/caving/FILES/survey_book_graph.pdf
You can also use them as templates to trace onto full blown 'plastic' waterproof notebooks with an indelible fineliner.
Over the last few years there's been significant advance in so called 'paperless' surveying, which uses a combined Laser rangefinder / clino / compass, and usually some form of handheld computer. The barriers to entry for this, in terms of equipment cost and availability, and technical ability are greater. Learning to survey by hand would put you in good stead for taking advantage of more recent advances.
Finally, of course by far the best way is to learn from someone who's currently doing this. Certainly there's lots of resurveying projects in the UK which I'm sure would welcome assistance!
The Wikipedia article is pretty good on this:
http://en.wikipedia.org/wiki/Cave_survey
From a practical point of view you are taking measurements with Compass, Clinometer and Tape Measure (or Laser Rangefinder) between a series of stations. Stations are mostly temporary reference points just chosen for their line of sight to the next station, though at the end of a survey or at a notable junction, you sometimes install 'permanent survey stations' as points of reference. In these enlightened days you should certainly avoid the temptation to mark the cave wall by scratching it or otherwise to help your partner locate the station.
Each of these measurements defines a survey shot (or leg), which together make the centreline going through the cave.
You also record information about the dimensions & nature of the cave passage around this arbitrary centreline (typically left-right-up-down data around the station, and ideally a cross section sketch).
Back on the surface, your meticulous shot data, notes & sketches are typically entered into a dedicated survey computer program such as Survex, which does all the necessary trigonometry and trendy loop closures to give you a line drawing in Plan & Elevation, which you then supplement with your data about the nature of the cave to produce the eventual drawn survey.
The BCRA publication 'Cave Surveying' by Anthony J Day is a really good reference, and useful for symbols page alone. Apparently you can get it for the cost of ?1 postage direct from the BCRA...
http://bcra.org.uk/pub/cs/index.html?j=11
In terms of actually doing this 'for real' you'll need a set of instruments, such as the Suunto KB-14 Compass / PM-5 Clino. These are expensive. Your best bet would be trying to borrow a set of instruments, most club's sets sit gathering dust 99% of the time.
You also need a fibre tape measure, and a 'survey book' to put it all down in. 'Open Frame' tape measures are more mud resistant and reliable.
Though bringing back 'publication grade' data will require professional instruments, you can learn to survey with more basic gear - just a sighting compass and an improvised clino with a protractor + weight on a thread, perhaps? Learning to survey is perhaps 5% reading the instruments, 95% writing up your book nicely, not making blunders, miscounting stations, placing stations in good locations, communicating with your survey partner etc.
A good test of your skills is to purposefully form loops in your surveys, and see what the closure error is.
I put together some PDFs with survey books in both the 'Arrows' and 'From-To' form a few years ago. They print well with a laser printer onto A4 paper, for guillotining and rebinding as survey books:
http://union.ic.ac.uk/rcc/caving/FILES/survey_book_arrows_2010_name_survey.pdf
http://union.ic.ac.uk/rcc/caving/FILES/survey_book_fromto.pdf
And graph paper for the flipside for scale sketches:
http://union.ic.ac.uk/rcc/caving/FILES/survey_book_graph.pdf
You can also use them as templates to trace onto full blown 'plastic' waterproof notebooks with an indelible fineliner.
Over the last few years there's been significant advance in so called 'paperless' surveying, which uses a combined Laser rangefinder / clino / compass, and usually some form of handheld computer. The barriers to entry for this, in terms of equipment cost and availability, and technical ability are greater. Learning to survey by hand would put you in good stead for taking advantage of more recent advances.
Finally, of course by far the best way is to learn from someone who's currently doing this. Certainly there's lots of resurveying projects in the UK which I'm sure would welcome assistance!
JohnMCooper
Member
The last time I read about the resurveying of Swildon's was in "The Adventures Of Another Pooh". Lets hope this one makes better progress! Count me in.
Les W
Active member
I have Willie Stantons survey data and want to computerise it to check accuracy. Providing the misclosures are acceptable and we can locate the fixed points within the cave then i propose using this as the basis for the survey (thus reducing much of the work) and just update passage detail. Then survey/resurvey the remaining passages as required.
First task is to extract his data from his notes (it is mixed in with all the other caves he surveyed) then see where we are.
I hope to achieve this in the next few months so we can actually start surveying in the cave this summer.
All help welcome...
First task is to extract his data from his notes (it is mixed in with all the other caves he surveyed) then see where we are.
I hope to achieve this in the next few months so we can actually start surveying in the cave this summer.
All help welcome...
JohnMCooper
Member
I've got a copy of 2 of Willie's survey books - I don't envy you trying to make sense of them! I note he uses decimal feet rather than feet and inches. Many years ago I had one of those tape measures!
whitelackington
New member
You should be able to make a lovely loop,
just pop down P.G.S. dive the sumps, pop back up into Swildons One,
then scamble over the dry stone walls and the wet, muddy fields back to Priddy Green Les
just pop down P.G.S. dive the sumps, pop back up into Swildons One,
then scamble over the dry stone walls and the wet, muddy fields back to Priddy Green Les
jarvist said:
Better is print it on office inkjet with waterproof inks (Epson's Durabrite) and impregnate as is showed on: http://cachtice.speleo.sk/impregnation/
You may use it without any cover in vertical parts hanged on your harness. If you use not too hard pencil you may rubber it under water too. And it is quite good archive too.
jarvist
New member
Mmm, I'm not a great fan of making Napalm at home.sluka said:
Between
- Laser printing (totally waterproof / smudgeproof) onto Aquascribe (a rag based waterproof laser paper, http://www.aquascribe.co.uk/)
- Hand tracing onto 95p Gelert A6 'plastic' waterproof pads (http://www.outdoorvalue.co.uk/products/161-gelert-fishingbushcraft-waterproof-notebook.html)
The Aquascribe gets a little bit soft when wet, and tends to get impregnated with mud much more easily than the glossy 'plastic' gelert waterproof paper.
The Gelert pads are also bound already, so you don't need a comb binding machine, or to faff around with rusting staples and butterfly clips.
Recently I picked up a Staedtler Lumocolor glasochrom pencil. It's kinda a grease pencil, except without the grease. Overkill & rather too bold for survey notes (its more like a crayon), but might be useful for Sample / PSS marking.
JohnMCooper
Member
Surely some form of standard layout and annotation needs to be agreed first? Has Les done this?
Les W
Active member
Not yet.
My prefrence would have been to use the Survex defaults as that is what I am familiar with, however it looks like Therion is the way forward so perhaps we ought to use a layout that Therion deals with?
I guess I'll have to download it and take a look when I have a minute (or ask somebody that knows already...)
My prefrence would have been to use the Survex defaults as that is what I am familiar with, however it looks like Therion is the way forward so perhaps we ought to use a layout that Therion deals with?
I guess I'll have to download it and take a look when I have a minute (or ask somebody that knows already...)
jarvist
New member
Mmm, I think coding standards are really quite important to avoid headaches later on.graham said:
Even something as simple as TEMPLATE.svx really helps to get people to enter the metadata & cross referencing in a sensible form, putting the page number of the original notes in correctly, showing how to use the *date command etc.
I always take the opportunity to have a gander at people's .svx files to see how they're formatted, and whether there's any new tricks to learn.
A system like Distributed Proofreaders - http://en.wikipedia.org/wiki/Distributed_Proofreaders - would, I think, work really well for this. I can't imagine they'd be particularly happy about us cavers smuggling archived survey notes into the Project Gutenberg work flow (but then again... you never know... some very dense technical literature has been typed up by them, as well as old phonebooks), but the software is open source and either it, or a similar setup, could be installed to a webserver somewhere.graham said:
Certainly you'd want a few passes over the data, and having these multiple levels of proof is built into the system on a page-by-page basis.
Of course, building an archive of .svx files is not as simple as typing up a linear book...
Just to comment on the PDFs, they appear to be scanned as 'Black and White'. If they were rescanned as greyscale they'd be more legible.