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Altitude Tracking Calculator

This page is under beta test.

If you have any problems, questions or comments please jot down your input data and send them to Bill Jackson.

This calculator determines the maximum altitude of model "Estes" style rockets by combining multiple (2 to 12) observer sightings to calculate a more accurate maximum altitude.

1. Enter the number of Observation Stations and press the "Add Number of Stations" button.

2. Enter the compass heading from the the Station to the Launch Pad and the distance between the Station and the Pad. If you enter the distance in feet, your altitude will be calculated in feet. If you want your altitude in meters, enter the distance from the Stations to the Pad in meters. Press the "Add Station" button and repeat for each Station.

For example if you had three observation stations where station #1 was 500 meters from the launch pad and could see the pad on a heading of 45 degrees, station #2 was 400 meters away from the pad reading a heading of 315 degrees to the pad, and station #3 was 450 meters reading a heading of 160 degrees to the pad, the results would look similar to this:

Note: Accuracy problems occur when observers are too close to the launch pad. Make sure your observers are about the same distance from the pad as the rocket's expected altitude. This will most likely be greater than 300 meters or 1000 feet.

3. Enter the compass heading and elevation angle from each Station to the Rocket Apogee.

4. Record the Altitude and Ground Track data.

Demonstration Data

To get an idea of how this calculator works, enter the following data into the above calculator.

Click "Restart Alticalc"
The number of stations = 4.
Station #1 reads a heading of 15 degrees to the Launch Pad and is 323 meters from the Pad.
Station #2 reads a heading of 112 degrees to the Launch Pad and is 256 meters from the Pad.
Station #3 reads a heading of 214 degrees to the Launch Pad and is 347 meters from the Pad.
Station #4 reads a heading of 311 degrees to the Launch Pad and is 367 meters from the Pad.
For the launch;
Station #1 reads a heading of 347 degrees to the Rocket Apogee and an elevation of 61 degrees.
Station #2 reads a heading of 146 degrees to the Rocket Apogee and an elevation of 72 degrees.
Station #3 reads a heading of 226 degrees to the Rocket Apogee and an elevation of 47 degrees.
Station #4 reads a heading of 295 degrees to the Rocket Apogee and an elevation of 47 degrees.
Click the "Edit Sightings" button and make small variations to the heading and elevation angles to see how errors in sighting measurement affect the results. Note: After you click "Edit Sightings" and enter the station number you want to change, you can click "Get Current" to see the currend data which you can edit.

This next set of data demonstrates how the sighting headings of each station intersect with the sighting heading of the other eight stations. All of these intermediate points (in green) are averaged together to arrive at the final ground position. (in red) It also makes a pretty picture.

Have fun!

Note: This could also be used as a combined exercise with your SAR Ground Team to develop percision in compass navigation technique.

JAVA applet designed and written by William H. Jackson, Majt, CAP, Santa Fe, NM