Some number crunching..

I took the log of my Flytec vario / gps / recorder and loaded it into an OpenOffice spreadsheet, where I parsed the data to get some neat numbers for the latest flight of the Pelican.


First, the original video of the flight :

Here is the climb altitude in meters, plotted vs time in seconds:

It shows a steep climb to 80 meters, and then a bit slower descent .. the reason it goes below zero, is not because we crashed and went underground, but because our runway has quite a bit of slope. it is about 20 meters lower at the end.





This one, is the climb/descent rate on m/s Vs time in seconds:


It seems to agree with a steep climb at about 4.6m/s, then a dip (need to look for that on the video) and then a slow descent at about 2m/s .

I think that the bottom dip at second 49, is because a bad GPS distance computation during the turn.. (Someone knows how to take care of that?)




This is aircraft speed, (computed from the GPS log, so it skews way off during the sharp parts of the turn)

The speed is calculated from the GPS lat/long deltas plus vertical speed component, so I am sure there is quite a bit of error there. Still, the graph shows most of the flight between 35 and 70 kph..  about what the nominal stall to VNE is listed for a goat.


And finally, the GPS Lat/Long data plotted as points on an x/y axis.






I am guessing it is a pretty ugly graph, (Looks flattened to me) because I have not yet compensated on my formulas for the fact that lat and lon degrees don't map 1:1 on an x/y graph.. ( It is more like  10:8 depending on the latitude. )

Anyway, it still illustrates the plane taking off from left to right, making a turn and back to the runway for landing.

You can clearly see the data points (1 per second) spreading out as the glider speeds up and then closing together after the landing on the top right.


Hope someone finds this useful.

Alx.