Thread: rowan dsw
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Old 2nd May 2014, 12:58 PM
neilL neilL is offline
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Join Date: Mar 2010
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Posts: 576

I think we need to sort out some basic stats here.

The sensitivity is not the same as accuracy and we all know that gaps change on a side wheel so that although the sensor has linear sensitivity the conversion to a distance will differ at 30 yards and 50 yards.

For a given distance you would need an independent measurement of the distance to the target when setting up the device. Tat measurement needs to be repeated and the mean and std deviation of that measurement recorded. So it may come out as 50.25 yes 0.05 or some such.

Then when you use the new device you have to take repeated independent measurements and again decide how many of the units are needed to record 50.25yds. The problem here is that the readings are not independent unless someone else is there to record the result without the shooter (observer) knowing what has just been output. Also eyes tire so there will probably be a change in the readings over time (and possible influence of light, cloud, etc) and that will be a systematic error.

At the end of it you will have a 'measure' of distance but the accuracy will not be as good as you think it might be. Do it once and the stats say the possible error is very large.

When used in the wild the measurement may be repeated a few times and 'that seems to be ok' is the measure of accuracy..

It looks like a great device to train with, on a course it will be a better readout than guessing it is more than 45, less than 50, give it 2.5MOA.
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