In message <ejujd4-cca.ln1@mail.specsol.com>,
writes
In sci.physics Vizzie <helpraptor@yahoo.com> wrote:
I need a way to measure visual angle of a target in the field. I'm
asking because I figured out a way of estimating target range and size
from two measurements of visual angle.
I was thinking of a cursor with three lines-one at the left, one in
the center and one at the right. The user puts the center line on the
target and then turns a knob until the target is inside the left and
right lines. Then the amount of visual angle subtended by the target
is determined from how far apart the lines are.
Any suggestions on how to measure visual angle are welcome. Thank you.
You put indicators on the knobs and calibrate against something known.
Or you could just go buy a WWII surplus rangefinder or even a modern,
laser hunting range finder.
Or a sextant.
--
Richard Herring
.
