FURTHER DIRECT COMPARISONS OF INCOHERENT-SCATTER AND MEDIUM FREQUENCYRADAR WINDS FROM AIDA-89

Mesopause level winds measured over Arecibo (18 degrees N, 67 degrees W) for the interval 1200-1416' h 10 April 1989 by the incoherent scatt er (ISR) and the MAPSTAR MF radars during AIDA '89 are compared. Imagi ng Doppler interferometry (IDI), full correlation and three dimensiona l interferometry analyses have been applied to the MAPSTAR radar data. To determine the measure of agreement at time scales less than the tw o hour integration intervals previously employed for published AIDA da ta, the overall interval was split into four 34 min segments, and each analyzed individually. The agreement at the shorter timescales was fo und to be as good as that for the 2 h interval with, as has been noted previously, the zonal component agreement being better than that for the meridional. The IDI and Full Correlation Analysis (FCA) apparent v elocities are in better agreement with the ISR winds than is the FCA t rue velocity. Sky maps of the distribution of IDI measured scattering point velocities are what one would expect if these represent actual l ine of sight wind velocities. We have looked at scattering point distr ibutions, and find no evidence in our data for the scattering point al ignment predicted by the volume scattering hypothesis. (C) 1997 Elsevi er Science Ltd. All rights reserved.