|Estes Alti Trak Altitude Finder|
|Pull in trigger until sited|
|Protractor With Weighted String Hanging Down|
Estes the model rocket company sells a device known as the "Estes Alti Trak Altitude Finder" which I purchased hoping it might be a little more accurate. With the Alti Trak line up the sites while pulling in a trigger when the point is found release the trigger and the angle is locked in. I started testing the unit on a utility pole and then a rubber powered model helicopter.
For the utility pole I computed it was 44 feet tall which could be fairly accurate as I read a standard utility pole is 40 feet tall but can be as tall as 120 feet. I then tried to estimate the maximum height of simple rubber powered helicopter in windy weather. The helicopter drifted downwind a fair amount so I subtracted 10 feet for the drift as the helicopter was coming down. Angle reading was 28 degrees which gave a tangent reading of .5317094311661 which multiplied by 89 feet gives an altitude of 47 feet which sounds reasonable.
|Tape Measure Extends to 100 Feet|
I plan to demonstrate this in some of the activities I do with kids. Even if it is not completely accurate I think showing how the math works is more important and to discuss where inaccuracies could be. To test it further I want to use this on a known height and see how accurate this is. I would also like to find a metric tape measure.