Milliradians: Ranging Example 1b
From Ex 1a we know the distance using the person's full height. However, you can’t always see a person’s whole body. For reliability and to avoid a decimal (we want it easy for expedience after all), consider the person’s heigth from the top of their head to the crotch: it’s one metre!
Head-to-crotch now appears as 3.2 mil. Round to 3 mil because we want it easy, so:
((head-to-crotch in metres) * 1000) / (mrad measured) = (range in metres)
(1 m * 1000) / 3 mil = 1000 / 3
≅ 330 metres
We’re off by 30 because we rounded. Try to be as precise as possible, but we preferred ease of use this time. Judging the balance of this is a skill, too.
