Today my local rocket association ( wwwl.lunar.org ) had a launch I was able to attend. The skies were clear, and not much wind to speak of. It was also great to see a bunch of larger rockets.

For the ground station, I wanted to get a boost with a directional antenna to reduce the possibility of loosing data. I found that one of my older wifi access points had an internal panel mount antenna that was good for 9 db gain. It also happened to have the same connector as the digi transceiver.

I put the antenna on the grass - pointed upward and hooked it up to the laptop. I started recording the telemetry as they announced each rocket prior to launch. As the rocket accelerated, I glanced at the computer screen and saw that it was busy gathering flight data.

Looking over the data I can see a few places where data was missed, but overall, it seemed to work very well. The biggest piece of missing data is when the rocket reaches the final 100 feet above ground level. Part of this was NOT line of sight, and I had pointed the antenna straight upward, so it was pretty impressive to me that it received all but the last 100 feet AGL.

The virtual flight is pretty interesting to me. You can see a lot of rotation in the rocket. This rocket has pre-cut fin slots, and I made no attempt to angle the fins, but obviously they are not straight. The rocket bobbles a little before the parachute opens, and then the nose cone sways beneath it. Perhaps the ejection charge caused some of the strange motions just past apogee.

I had assumed that the 9dof sensor fusion would be majorly confused by this high rate of acceleration, and possibly do strange things to the orientation result. However, I am quite pleased with how it turned out. I appears to be pretty accurate, and apogee is obvious

A second launch was made, however, the telemetry ran out of battery power, so no data from the second launch is available. Below is a graph of the recorded flight: