distance measurement

You get a stick with a reflector thingy on it and measure to the reflector thingy rather than the object.

If it's across level ground, use a trundle wheel. Ones for schoolchildren's use are cheap. Depends on the accuracy required.

Owain

what is wrong with a tape?

what is wrong with a tape?

OK, its usually across a valley and there may be water between me and the target area and of course I need the line of sight distance not the tape measurement lying on the ground so, without a reflector, will it work as is ? ta

Some of the better Leica Disto jobbies will do it with ease. The posh ones even have a colour screen which lets you zoom in on your target to pinpoint where you are measuring to.

Vass explained on 13/11/2012 :

Using a sighting compass, take a bearing on the object, mark on the ground where you take that sighting. Now move from that point to another point, adjusting your position until your bearing is + or - 45 degrees of your first sighting and place a second marker. Distance between the two markers is same as the distance from the object - give or take.

Google Maps??????????????

Baz

I use a Bosch one. I'll check what the spec is later but, IIRC, it goes up = to about 50 metres, so not as powerful as the one you'd need.

What will you be aiming at, and what light conditions are you expecting? Th= ose are the two biggest factors (besides the distance) in deciding whether = it'll work for you.=20

Mine works superbly over short distances, pointed at light-coloured targets= or in the dark. It becomes increasingly tricky as those factors get less i= deal. The longest distances I've measured with mine are about 30 metres, wh= ich works perfectly on a cloudy day with brick walls, fence panels etc. as = targets, even at odd angles.

For longer distances, and with cluttered target areas, it becomes increasin= gly difficult to see the laser spot. You can normally find it by carefully = sighting along the side of the case. For 60 metres, you might have to resor= t to a tripod or some other way of keeping it steady. I guess a longer-rang= e unit will help by having a correspondingly brighter spot.=20

If you can make the measurement in the dark or in half-light, it becomes en= ormously easier and you can measure to much less ideal targets.

I have to say, I think they're superb gadgets for general surveying-type us= es - much less hassle than a tape, most jobs become one-man and it's more a= ccurate too.

Cheers,

Colin.

JGH

Or a piece of string and a 10M Tape.

Baz

Rubbish.

MBQ

Half there. You also need to sight back to the orginal point at + or - 90 deg to the orginal bearing. Then the distance between the orginal and second point is more or less the distance to the point being sighted.

Yep, got my eye on a Bosch too

Archery Targets

Wooded shade

Perfect, thanks Colin

Man at B&Q formulated the question :

Says the Man who could not offer any method, nor could explain his rubbish comment!

Dave Liquorice formulated the question :

Deer stalking?

Tie a string to the arrow.

Video the arrow, calculate its velocity between two known points, and extrapolate into distance for the time of flight.

I can't think of any method involving a barometer yet.

Golf rangefinder.

both no good, rely on known height of target (Gold flag pole) Field Archery targets are mixed sizes or even 3D

In message , Harry Bloomfield writes

However, the problem is the essentially same as measuring the height of a tree. The ground needs to be level.

At a certain distance D1 from the tree, measure the angle A1 to the top (a theodolite is the 'correct' instrument). Then walk a measured distance D2 closer or further away from the tree, and repeat the angle measurement (A2). You can then draw to scale what you have done, and measure D1 + D2, or calculate it using trigonometry (simultaneous equation involving tanA1, tanA2, D1 and D1 + D2).

It obviously can be triangulated, but not like that, I agree. :)