I've been looking the flash logs downloaded from ArduCopter, and I don't seem to see any sort of header information (in the file itself) for logging parameters. I've also been looking at APMLogVisualizer, and a few threads about updates to that utility
It seems that the log lines available and the parameters that appear for each are in a constant state of flux from one version of ArduCopter to another, and it's a battle to keep even mission planner up to date. I don't have a problem with changes to the format - I expect as much as the software is constantly being improved and developed.
However, it would be nice to be able to see what is what without having to hit up the APM source code. And it would be nice if the logging format was self-documenting enough that log analysis tools would not need to be updated or reconfigured in order to label parameters correctly (assuming those tools were programmed robustly, which APMLogVisualizer is admittedly not). This would also make it much easier to backwardly support log formats from previous versions of APM.
I think the solution to this could be as easy as having APM write a header for each of the enabled log line types - with all of the parameter names for that type - at the beginning of each new log file.
Lastly, there have been times I've looked at the datalogging page on the wiki and it seemed not to match what was actually available in ArduCopter. I think it's important to make sure this information is up to date when a new version of firmware rolls out the door. It would also be nice if all of the parameters for each type (along with their units of measure) were listed. Is there any chance that could be added when the new documentation goes live?
I realize I could make some of these contributions myself, although I'm not quite ready to do so yet. Any feedback (good idea, bad idea, might not work, etc.) is welcome.