Extract state data from recorded flight in RF9

DavidLL

New member
Hello,

I am working on an investigation project where it would be very beneficial to have kind of realistic rc aircraft pose data (position and orientation at each timestamp) in order to test different algorithms.

Does anyone know if it is possible to extract this kind of data from a RF9 flight recording? Could this be achieved with flightaxis link?

Thank you

Regards
David
 

marcushh777

Well-known member
Good morning, David,

It should (in theory) be possible to do something like you're describing (at least indirectly) due in principle because the "recording" is not a video recording ( like mp4 or ogg ) but is RealFlight ( flight ) data similar to the data stream(s) used in multi-player mode. In fact, it is possible to fly with yourself in a multi-player situation using an Rf9.5 recording.

I created an acrobatic recording of myself flying from Carl Henson Field; I used the Timber (green trim) with slats, and recorded take-off to landing (about 7 minutes) just normal aerobatic flying.

In test (1) I opened and played the recording after selecting another field first. You guessed it, you can play the recording over any field backdrop you want.

Next test (2) I opened and played the recording over Carl Henson Field; this time while the recording was playing I selected a "second" Timber. I could no longer see my recorded plane (focus is on the new plane) but I could hear it flying and I could see my user name associated with the recording and the "first" plane [ marcus ] following around the screen, just like in multi-player mode.

Final test (3) I took off with the "second" plane and literally flew around with the "first" plane in my recording. I have not done so yet, but I suspect that it is possible to play back more than one recording at the same time and fly with multiple "airplane selfies," if you will, just like in multi-player mode.

It really comes down to the format of a RealFlight recording, whether it is proprietary, and whether there is an editor that would allow viewing the recording as a data stream frame-by-frame.

The file is NOT a text file, but much of it is readable in notepad. The field, the plane type, the user, the plane's attributes, and so forth. Then the file clearly goes into a pattern that looks like what I suspect is essentially flight log data (frame by frame) in time. The trick will be decoding the frames (whatever I mean by that) to extract the plane's attitude (flight state, and speed, motor rpm, etc) and time-stamp, or frame number.

This is something that the Knife Edge people ( Horizon Hobby ) may frown on, or on the other hand it may be something they would be willing to help us with; I am not a spokes person and have no idea about that... but the bottom line is that it should be possible to pull moment by moment 'state' data from the proprietary flight recording.

PS edit: to be complete; I tried to play-back more than one recording at a time, which did not work, and Rf9.5 crashed. oops

marcus
 
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DavidLL

New member
Marcus... thank you very much for your answer.
I was assuming that the recording file was in a proprietary format but did not realized that I could try opening it as a text file.
I am using Matlab for my investigations, hopefully I can build some script to decode that information.

Will let you guys know if I come up with something useful.

David
 

TimeF3A

New member
First post here, but I was looking for this capability. The very few recordings uploaded to the swap pages look to be ***.rfx files, but are similarly encrypted.
The question would be, is there a way to extracts the flight data; location, attitude, time, from these rfx files?
 
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