Hello all:
A couple of year ago we went through this debate and I (was
taken to task) learned a lot about the new $200 alitimeters.
However, we are rarely fly overhead, but at some angle, which means we
are much farther away than "up"
However, a soarer came on,
who had done his math (geometery) and he simple stated that at the
height/distance of someone's claim, a diameter of 1/32 piano wire held
at arms length would completely cover the image of a 2m" ship (at that
height - not distance!) So if the ship is 4 meters, a piece of 1/16
wire.... The geometry doesn't lie!!! And this was assuming that you
were looking at the ship perpendicular to the top or bottom, (or coming right
at you, yehhhh, sure!!!) not at the angle we usually see the ship.
This distance was about 1/2 of the height claimed.
My
son held the two meter junior altitude record, ca 1800ft during the
70's. He had at least 15/20 vision -none of us witnessing the claim could
really see the ship well enough to take accurate readings, so he flew
overhead till we could see it and take readings with transits. I am sure
at 2500ft directly overhead, not at an angle, (most people think 75-80 degrees
is overhead) he would have had a very hard time.
The biggest problem
with the cheapies is that they are not temperature compensated, or VERY poorly
so.
Those of us who were involved with altitude records during the
70's and 80's learned very quickly that how high you think you are and
how high a Winter Baragraph tells you are very different. Jack Hiner's
record of 5000 was skill, luck, good weather(no haze), and trememdous
eyesight AND it took him many, many , many attempts. His ship was
also BIG!!! enough to house a full scale Winter Baragraph!!! What could he
have done with a 10 gram - quarter size baragraph????????
Good luck and have fun!!!!
Jim
