plotting tracklog data script


I created a small script that will convert tracklog data into a kml file for google earth viewing. For some reason the flight path seem very erratic. Im wondering if this is becaue of low accuracy data on the page or if I am interpreting the data incorectly in my script. heres an example kml ACA263


I plotted the tracklog in Excel and I’m seeing the same jumps in the track. I’ll see if I can get Karl, our lead mapping guy, to chime in on this.


figured it out. Turns out i needed to convert the coords to a decimal degree format from the Degree/Minutes format displayed on the tracklog.

ie. the coordinate 4939N corresponds to 49 degrees and 39 seconds NOT 49.39 degrees.

But is infact 49.65 degrees aftern the correct conversion.

Here is the working kml ACA263 Working.


Glad you figured it out… I had only kind of superficially followed this conversation, and I was afraid we had a bug in our fa_internal_latlong_short_to_double function, which has been pretty carefully scrutinized.

Over time the trackstream API has migrated more and more to just using a strict floating-point representation of degrees without hours/minutes, although internally we have been continuing to use a short integer representation that still maintains the full precision we receive while minimizing space in the RAM-resident database.


Care to share your script?

I suggested in an earlier post that the timestamp and position reports include the seconds to make the track less jumpy.

I also asked if FA could provide a downloadable version of the track log in CSV format; KML would be a bonus.


I was able to modify the file to track one of my flights, but I can’t seem to get the absolute altitude “restriction” applied. When I play the tour, it exceeds 7000 feet and climbs to about 12000 which then goes down to ground 2600 feet and loops back up to 12000. When I stop the tour, and zoom out, it seems to be following the track. Flight being used is … V/tracklog

I modified the script to show the following after my name. Any idea on the altitude problem much appreciated:

The problem also exists in the original script, though it climbs higher before looping back. In other words, there doesn’t seem to be level flight :smiley:

Quickest way to test the below is to copy and paste the script into a notepad file (text base) and save it as a .kml file. If you have Google earth installed, when you double click the .kml file you just saved, it will open and show you my flight path. It’s when I take the tour in Google Earth that things don’t seem to flow.


<?xml version="1.0" encoding="UTF-8"?> 3D Flight Path for Flight N1943L root://styles#default+icon=0x307 1 absolute -90.10w, 32.52n, 3000 -90.10w, 32.53n, 3600 -90.08w, 32.57n, 4100 -90.08w, 32.58n, 4600 -90.08w, 32.60n, 5100 -90.08w, 32.62n, 5500 -90.08w, 32.65n, 6000 -90.08w, 32.67n, 6400 -90.07w, 32.68n, 7000 -90.07w, 32.72n, 7000 -90.07w, 32.73n, 7000 -90.07w, 32.77n, 7000 -90.07w, 32.80n, 7000 -90.05w, 32.83n, 7000 -90.05w, 32.87n, 7000 -90.05w, 32.88n, 7000 -90.05w, 32.92n, 7000 -90.05w, 32.95n, 7000 -90.03w, 32.98n, 7000 -90.03w, 33.02n, 7000 -90.03w, 33.03n, 7000 -90.03w, 33.07n, 7000 -90.03w, 33.10n, 7000 -90.02w, 33.13n, 7000 -90.02w, 33.15n, 7000 -90.02w, 33.18n, 7000 -90.02w, 33.22n, 7000 -89.98w, 33.35n, 7000 -89.98w, 33.38n, 7000 -89.98w, 33.40n, 7000 -89.98w, 33.43n, 7000 -89.98w, 33.47n, 6000 -89.98w, 33.50n, 6500 -89.97w, 33.52n, 6000 -89.97w, 33.55n, 6000 -89.97w, 33.58n, 6000 -89.97w, 33.60n, 6000 -89.97w, 33.63n, 6000 -89.95w, 33.67n, 6000 -89.95w, 33.68n, 6000 -89.95w, 33.72n, 6000 -89.95w, 33.75n, 6000 -89.93w, 33.77n, 6000 -89.93w, 33.80n, 6000 -89.93w, 33.83n, 6000 -89.93w, 33.85n, 6000 -89.93w, 33.88n, 6000 -89.93w, 33.92n, 6000 -89.93w, 33.93n, 5600 -89.92w, 33.97n, 5200 -89.92w, 34.00n, 4700 -89.92w, 34.03n, 4200 -89.92w, 34.05n, 4000 -89.90w, 34.08n, 4000 -89.90w, 34.12n, 4000 -89.90w, 34.15n, 4000 -89.90w, 34.17n, 4000 -89.88w, 34.20n, 4000 -89.88w, 34.23n, 4000 -89.88w, 34.25n, 4000 -89.88w, 34.28n, 4000 -89.87w, 34.28n, 4000 -89.87w, 34.32n, 4000 -89.87w, 34.32n, 4000 -89.87w, 34.35n, 4000 -89.87w, 34.35n, 4000 -89.87w, 34.37n, 4000 -89.87w, 34.38n, 4000 -89.87w, 34.40n, 4000 -89.87w, 34.40n, 4000 -89.87w, 34.43n, 4000 -89.87w, 34.43n, 4000 -89.85w, 34.45n, 3900 -89.85w, 34.47n, 3700 -89.85w, 34.48n, 3500 -89.85w, 34.50n, 3200 -89.85w, 34.52n, 3000 -89.85w, 34.53n, 2800 -89.85w, 34.55n, 3000 -89.83w, 34.57n, 2900 -89.85w, 34.58n, 3000 -89.83w, 34.60n, 2900 -89.83w, 34.62n, 3000 -89.83w, 34.62n, 2900 -89.83w, 34.63n, 2800 -89.82w, 34.65n, 2700 -89.82w, 34.67n, 2800 -89.82w, 34.68n, 2700 -89.82w, 34.70n, 2800 -89.80w, 34.72n, 2700 -89.80w, 34.73n, 2700 -89.78w, 34.77n, 2800 -89.78w, 34.80n, 2600 -89.78w, 34.82n, 2300 -89.78w, 34.85n, 2000 -89.78w, 34.88n, 2000 -89.78w, 34.90n, 1600 -89.78w, 34.93n, 1400 -89.78w, 34.95n, 800