Originally Posted by
SASless
Airplane,
Nice effort and interesting result!
As you manipulated the data into the graphic you produced.....what do you see in the last 10-20 seconds that piques your interest the most?
What do you see as to ROD and Airspeed (can we discern Airspeed vs Ground Speed from the raw data compared to the Weather Data for Wind direction and velocity?)?
In no particular order:
1) I am circumspect of the last few altitude readings (where it climbs fast) because they are inconsistent with ADS-B vertical rates, a 200' climb in two seconds at low ground speed seems improbable, and the delta between the baro and geo heights changes at the end. There are two possible reasons for these inconsistencies that I can think of:
- a) There was unusual pressure on the static ports due to unusual aerodynamic maneuvers, and that caused inaccurate PA readings.
- b) We are missing some ADS-B velocity messages, and those messages contain positive vertical rates and geo deltas that are consistent with the altitude gain.
2) The horizontal jitter in the ground track is consistent with 5m ADS-B precision and accuracy. It doesn't mean the aircraft was actually bouncing around as shown.
3) Why did the helicopter ground speed drop to near 0 at the end? What events led to that?
4) Why did we lose the signal at such a high altitude? Earlier in the flight, only a couple of miles away, ADS-B exchange received the signal as low as 775'.
I haven't spent any time thinking about factors like wind.
Edit: Credit where credit is due. A lot of the work in the visualization is courtesy of adsbexchange.com