Surveying Maze Caves

[cavemanjonny]

There is a large multi level maze cave nearby that has never been surveyed to completion. I have dabbled with the idea of taking it on. The only problem is, I have no idea how to go about mapping something so complex. It lies outside of my realm of experience. There are 3 levels, all of them mazy, all of them highly interconnected. Any suggestions as to how to best manage such a survey?

[Scott McCrea]

Very carefully. But seriously, one trick we have used is to develope a set of 'rules'. For instance, establish a rule that survey will right and down. If there is an option, turn right or go down. Eventually, you will cover the outside of the lower level. You can choose all sorts of rules. Eventually, you will cover the entire cave.

Another thing that is very important in mazy stuff is to mark the stations very well. Mark them so they are easy to find and easy to know exactly what station it is. Because you'll probably be tying in from multiple directions.

Of course, surveying it is one thing, the cartography is a whole different ballgame.

[Ralph E. Powers]

Jonny I'll try to scare up Jim Olsen who has mapped some of the crazier caves in Utah and Brandon Kowallis who has developed some neat programs (computer) that helps with crazy multiple level mazy caves.
I'll let you know on those.

[cavemanjonny]

Cool, I'd appreciate it.

[Bob Thrun]

Cavers in the Virginia Region have done thorough resurveys of several maze caves. Bob Hoke wrote an article in Compass & Tape on the Paxton survey. One rule that we had was that whenever we got to a junction, we would take the branch that was heading back toward the entrance. A practice of surveying the biggest or easiest passages first almost certainly insures that the project will not be finished. Very few want to mop up all the poor leads.
Computer software is not a problem.

[cavemanjonny]

Computer software is not a problem.

Right, I'm thinking that 99% of the difficulty will be related to actually physically surveying the cave in as efficient a manner as possible and recording data in a meaningful way.

[Ralph E. Powers]

As I understand it loop closures are the biggest headaches. If the compass readings aren't right on then the map is going to be way off. Hence doing front and backsights help ensure accuracy, so I've been told.

[Scott McCrea]

Computer software is not a problem.

Right, I'm thinking that 99% of the difficulty will be related to actually physically surveying the cave in as efficient a manner as possible and recording data in a meaningful way.

Sounds like the project just had it's cartographer volunteer.

[George Dasher]

My advice is to find a good loop closure program that can do simultaneous loop closures using least squares math. Hopefully, many (or most) survey programs do that now.

Give each station an individual designation, and keep your working map up to date.

Also full front and back sights are a good idea.

[Chris Chenier]

You'll want to bring along line plots and/or copies of drafted maps from previous sessions in order to easily see where to go next.

You should seriously consider using Auriga (http://www.speleo.qc.ca/Auriga) on a Palm PDA. It's free and you can get inexpensive older Palm models on eBay. If will allow you to see your line plot as you go, help you sketch to scale, identify loop closure errors on the spot, and see the data for the entire cave (to see where you're connecting to). Data can be imported/exported to Compass for loop closure reduction and other work requiring a "real" computer (printing, 3D animation,...).

Make sure to leave permanent stations, and mark them as such in Auriga to help you find them faster when you connect. By writing a note (in Auriga) about the exact location of such a station, you can leave stations with less visual impact.

Chris

[barcelonacvr]

edited