PAC3 Magnetic Data, Flight 6

Once again I flew a Honeywell HMC2003 three axis magnetic sensor to collect data on the rockets attitude. From top to bottom, the traces in the plot are longitudinal axis, lateral axis one, lateral axis two. The periodic blips in the data are caused by the RDAS piezo buzzer. The effect is not magnetic, it is from the current pulled by the buzzer causing the battery voltage to sag a bit. I added a 100uF capacitor this time and it has helped but not enough. Next I will add a 10 ohm resistor in series with the positive power lead to the sensor.

plot of three axis magnetic data

The two lateral axis show a definite roll of about 2 revolutions per second. The roll is caused by misalignment in the 2 inch extensions I made to the forward fins. I tried to get them on straight but I obviously didn't do a very good job.

Next is just the longitudinal axis sensor. I am not sure if the oscillation in this is due to variation in the vehicles pitch or misalignment of the sensor. I really need to work on some software to convert this to angles.

magnetic data from longitudinal axis only

Next I zoomed into the first half second of flight. There is a very noticeable effect from the launch rail at the beginning. The rail was a BlackSky rail made from aluminum but it was reinforced with a length of iron pipe.

first second of flight showing effect of iron pipe