Poor Man's Digital Survey Device

[graham]

An interesting development but the magnetic compass chips in mobile phones are not good enough for a BCRA cave survey Grade 3 let alone Grade 5.

The DistoX has three orthogonal high resolution sensors for the magnetic field which is why it can be used for BCRA Grade 5 cave surveys.

But a Grade 3-ish survey is better than none, don't you think. I have a number of caves to survey and a Grade 3-ish survey will do fine for me. No-one else will do it so it'll be good just good to get even a rough survey done on them...

Regards, Mel.

Obviously I have no experience with this particular device, but I do have experience with both a DistoX and with traditional tape & compass set ups & I rather suspect that you could do a grade 5 survey with the latter just as quickly as you could a grade 3 with this device. The main reason for using the DistoX/PDA/Therion method is not so much that it is faster - I doubt it is, the rate limiting step on most survey trips is the time taken to do the sketching - but that the data are so much easier to process post-trip and the results generated are so good.

 

[andrew]

Yes grade 3 is better than none, but I doubt this will be grade 3, and why waste time doing a grade 3 when it is as quick, probably quicker to do grade 5 with kit that hardly costs more. (Some new kit will come, I am sure.... but in the mean time there are about 50 DistoX in the uk, that seems to be far more than the surveys that are been produced)

Anyway it is not the centreline that is that important (but you might as well get it right) diagrams make the survey, and the spays available with a separate instrument to drawing pad, means that that things can be drawn in the right place, returning cave surveying to science from an art, although art does help

Andrew

 

[notdavidgilmour]

Really good info on this thread.  Cheers guys.  I've recently carried out a survey of a smallish (63 mtrs long) cave in North Wales using a tape measure (remember them) and a compass.  It was just to settle an argument more than anything, but I'm planning on using a more hi-tech method over the coming weeks.  I am interested to see how accurate my original map is.