How to analyze and understand log files from Pixhawk

I’m trying to extract some parameters, specifically those related to GPS and positions, from the log files from my Pixhawk to use in another application. Do any of you know where I can find more
information of how to interpret all the data?
Typical lines extracted from a .log file would look like this:

GPS, 814489566, 4, 39008400, 1928, 12, 0.78, 59.3449062, 18.3896469, 10.06, 20.65, 3.41, 103.20, -0.18, 1
BARO, 814514665, 8.295867, 102601.9, 18.12, 0.2622241

What does that 2 lines tell me? Long and lat I could figure out, but the rest?

Did you have a look at the available Tools?
http://dev.px4.io/flight_log_analysis.html

The header of the log should contain the field names such that you can extract which number stands for what.

Ok, thanks. But how do I find out what the different names in the header agtually means? Some of them I can understand, but not all of them.

It’s a bit late but: I assume you want to analyze .ulog files captured or streamed by the autopilot. The logger which does that basically records a certain set of uORB messages at different frequencies. These messages are all defined in this folder: https://github.com/PX4/Firmware/tree/master/msg in the comments of the definition you should find more details about the content. If you still have specific questions feel free to ask directly here or also on px4.slack.com.