"How high did that rocket fly?" is a question frequently overhead at launches. The Altitrak (Estes #302232) attempts to provide an answer to this question. It is a hand-held unit which relies on a human observer taking a measurement at apogee (highest altitude reached). The measurement taken is the elevation angle at which the model rocket reaches its highest point.

As it measures elevation angles and not (directly) altitude, it is technically speaking an inclinometer, not an altimeter.

How to use the Altitrak

The observer positions his/herself at a set distance (500 feet) from the launch pad, at a right angle from the wind. Point the device at the model rocket on the launch pad. Pull (and hold) the trigger and signal for launch.

Track the model rocket as it goes skyward through the sight. When it reaches apogee, release the trigger to lock in the measurement. The height can now be read off the swing arm.

The Estes Altitrak can measure peak altitudes of over 1,300 feet.

Altitude calculation tool

To obtain measurements for any distance from the launch pad (not just 500 feet), use this free online tool to calculate the height.

Pros

This rocketry tool offers a quick and easy method to provide a rocketeer with a rough estimate of how high a model rocket flew. Results are available instantly. It comes fully assembled, no assembly required.

This measurement method doesn't require installing anything in or on the rocket. On-board altimeters add weight, making them usefull only for more powerful model rockets. Measuring equipment also won't be lost if a rocket gets lost.

Cons

This is not a very accurate means to measure altitude, nor is it intended to be.

Results are provided in a range more than an exact number. The height of the observer, or more exactly, the height of the Altitrak was held at the time of measurement play a role, which is not taken into consideration.

As it relies on a human observer, accuracy can become an issue, especially as we are dealing with model rockets moving at great speeds. It also assumes the rocket follows a perfectly vertical path. If the rocket moves towards or away from the observer, it will cause the observer to perceive the rocket to be closer or further away.

Don't let these issues prevent you from using this rocketry tool. It is sufficient for a quick, rough estimate of how high a model rocket flew. For improved accuracy, two Altitraks (two observers at opposite sides of the launch pad) can be used and the results averaged out.