This note describes some changes incorporated in the NCAR C-130 aircraft data processing software that have been developed to improve the quality of velocity fluctuation measurements. These improvements result from more refined estimates of time lags for different sensor outputs, changes in low-p... Show moreThis note describes some changes incorporated in the NCAR C-130 aircraft data processing software that have been developed to improve the quality of velocity fluctuation measurements. These improvements result from more refined estimates of time lags for different sensor outputs, changes in low-pass filtering, a new static pressure port calibration, and a new GPS unit. The primary motivation for this was: (1) the use of circular flight patterns for turbulence measurements which results in more stringent accuracy requirements in some instruments because of the large variation in output around a circle; and (2) the observation in EPIC and DYCOMS-II that the turbulent momentum flux vector in the planetary boundary layer (PBL) was modulated by aircraft heading. Show less
