The Estes 302232 Altitrak is a handheld device used to track model rockets and calculate their maximum altitude. The device features a forward sight, a trigger, and a swing arm with a height scale to read altitude directly in meters or feet.
To use the device, the user must first pace off a specific baseline distance from the launch pad (500 ft for low altitude rockets, 1,000 ft for high altitude rockets). The user then holds the device at arm's length, points it at the rocket, and pulls the trigger to track the rocket through the forward sight. When the rocket reaches its apogee, the user releases the trigger and reads the height indicated on the swing arm.
You should pace off 250 ft (76 m) from the launch pad.
You should pace off 1,000 ft (305 m) from the launch pad.
Multiply the angle tangent by the baseline distance.