To better service some requests from our customers and to troubleshoot some interesting crash situations, we had the need to develop a log file viewer that is compatible with the A2 flight controller as recorded on the iOSD mkII.  This simple utility allows you to view speed and altitude that is refereneced to a point on Google Maps without having to upload your .DAT files to any servers.  All the processing is done in your browser so you don't have to upload 300 MB files...  

https://www.mapsmadeeasy.com/log_viewer

The simple output can be exported to Google Earth using a downloadable KML.  We recently added a full data CSV output of all the available data at its native refresh rate of 200 Hz.  This is the same data that can be viewed in the DJI software but can't export to use for other purposes.

We added the Roll, Pitch and Yaw calculations by customer request but they are not part of the raw output.

These are the colums that are available in the CSV output:
Latitude (Deg)
Longitude (Deg)
GPS Altitude (m)
N Velocity (m/s)
E Velocity (m/s)
D Velocity (m/s)
Velocity (m/s)
Ground Speed (m/s)
Accelerometer X (g)
Accelerometer Y (g)
Accelerometer Z (g)
GyroX (rad/s)
GyroY (rad/s)
GyroZ (rad/s)
Barometric Alt (m)
Quaternion X
Quaternion Y
Quaternion Z
Quaternion W
Roll (deg)
Pitch (deg)
Yaw (deg)
Magnetic X
Magnetic Y
Magnetic Z
Satellites
Main Voltage (V)
CAN Voltage (V)
Elec Voltage (V)
Sequence (200 Hz)

Enjoy!

Forgive newbie question, but how does one access the .DAT file from the aircraft, via the A2 Assistant?  Thanks

The files are on the sd card in the iOSD mkII.  Nothing is recorded in the A2 itself.  At least not that we know of.