Moderator: Moderators
NZcaver wrote: If you're not doing so already I would suggest shooting 2-3 distance measurements for each shot, and if they are consistent then your question has been answered and you should concern yourself no longer.
NZcaver wrote:Since you were kind enough to quote my words from long ago, I must now confess I occasionally used some of those "dummy" techniques myself. Especially for shorter shots in awkward positions - which, judging by your fantastic literary works, most of your surveying seems to be.
GroundquestMSA wrote:If the target affects the accuracy though, then would shooting my hand twice give me two identical incorrect readings?
I'm wasn't complaining, I am a dummy. I wouldn't be too surprised to learn that I've been doing something tragically wrong for the past few years and that all of my surveys are crap. However, if you keep poking fun of my trip reports like this I just might run off and cry. Probably not. Should have a new one tonight.
JSDunham wrote:We've been cutting out circles from the bottom of white plastic quart yogurt containers and bringing them in with the survey equipment. Durable, cheap, waterproof, washable, and the most reliable (according to my testing in the dark in fog, which is the best analog for our caves here in the northeast; tested compared to white paper, shiny white plastic, foil, mirror, and shiny black plastic).
JSDunham wrote:We've been cutting out circles from the bottom of white plastic quart yogurt containers and bringing them in with the survey equipment. Durable, cheap, waterproof, washable, and the most reliable
Bob Thrun wrote:Better yet, put some retroreflective tape (like Scotchlite) on your target. You can get it at any auto parts store. It greatly increases the range. Having > 50 meter shots would make sketching hard, though.
GroundquestMSA wrote:It appears that for practical cave surveying purposes, any target will do.
JSDunham wrote:GroundquestMSA wrote:It appears that for practical cave surveying purposes, any target will do.
I have to disagree--I think it very much depends on the cave.
JSDunham wrote:GroundquestMSA wrote:It appears that for practical cave surveying purposes, any target will do.
I have to disagree--I think it very much depends on the cave. Using a Disto, I have found dramatic differences in high-humidity conditions. Outside testing in good weather was always fine (hence my testing in fog rather than clear air). The humidity in our caves means swirling clouds of fog, dust, and particulates that diffuse the laser and make long readings difficult. A good target makes all the difference in these circumstances. Likewise, irregular, angled, wet, or muddy surfaces (i.e., most stations) are not always reliable and the target again makes the difference.
GroundquestMSA wrote:shot 1 - 33' 7" 1/2
Return to Survey and Cartography Forum
Users browsing this forum: No registered users