tracking ball distance

[programmernut]

I want to determine the distance a ball is thrown, rolled as in a football throwing contest.
I have looked at RFId, GPS and other methods but would love some insight.
My vision is the smarttag, transmitter is located inside the item, broadcast to a receiver which then updates the database

[toejam]

this is only for fun and no cynicism implied, but why not use a tape measure?

[programmernut]

could be for the same reason you don't save gas by using a horse and buggy...
no cynicism implied

[dyarker]

Two ultrasonic "tape measures" on fixed height tripods at start line. Some solid geometry in a program gives distance.<p>Infrared laser LEDs along one side of field, infrared detectors along other side. Blocked beam indicates distance.<p>GPS receiver in the ball isn't accurate by itself, use differential by putting another receiver at start line.<p>May things can be done, less than half should be. It is harder to be accused of inaccuracy with a steel tape than it is with a bunch of electronics.<p>Cheers

[toejam]

well if you think about it, a good system of public transportation and a bicycle would'nt be such a bad idea.

[toejam]

bye the way ther is a 40.00 optical rengefinder listed in google good between 10 and 75 yards

[jwax]

Overhead drone with a camera? Grid markings om ground, or a reference stick on ground would help.