7' Single validity bad. 9' Dew point is greater than temperature. The reporting airport refers to the ground station at which the particular observation was received, and is generally, but not always, an indication of the approximate location of the aircraft. W' for wind, 'T' for temperature, 'B'for both. G' means roll 5 degrees, '.' means not reported a flag to indicate corrections, if any.
Input is from the nimbus acars directory ascii acars data.
I perform the following tests and corrections. This is indicated by the correction flag f . In addition, all Delta MD88s have the observation time set to the report receipt time, because they always report 0000 as the obs time. I assume reports from the same aircraft are unrelated if more than 20 minutes separates them.