It seems important to report on this. The WINDII-HRDI communities were strongly represented of course, with collaborations from the optical/radar communities. The latter were few in number - I was the only MLT (non ISR) radar person.

The WINDII-HRDI data set, and winds products, continue to demonstrate their unique and powerful global coverage in the MLT (and now also Stratosphere). It is close to the time when the ground based GB radar/optical systems' abilities to observe temporal variations of all wave types and their interactions, can/should be combined with the UARS global-spatial views.

The validation/calibration processes are well advanced, but there remains the need to understand some differences in magnitudes (eg of wind vectors, and derived tides) between some ground-based radars/opticals and UARS.

i) The MFRs have been most involved with HRDI validations; and magnitudes of speed ratios (HRDI/MFR) of 1.2 to 1.5 (70-95 km) are common (often the larger 1.5 at 95 km). We are well advanced with assessment of FCA "normalizing" factors (Rx saturation, S/N, Sampling rates) at Saskatoon, and we know others are active. The issue of total radar-pulse reflection and group retardation is also crucial, and VIP as low as 85-90 km in summer-day conditions ( all year at Equator!). Corrections for this in the data sets are quite simple we believe.

ii) The meteor winds (MWR) also require study, as some HRDI/MWR comparisons also show speed ratios more than unity (scatter-plot slopes not unity); this is not surprising, as MFR/MWR comparisons for years have not shown any significant differences (climatologies; co-location).

iii) Thirdly, GB optical - radar colocated comparisons have enormous significance. There have been two comparisons in the Canadian Prairies involving MFRs and FPIs (Green-line at Saskatoon, OH at Calgary). Scatter plots, histograms (speed ratios, vector angle differences)show no significant differences (ie unity ratios, zero angle diffs at 88, 97 km). Daily studies, however, indicate GWs modify (are seen by) MFRs and FPIs in different ways, due to the different spatial-temporal averaging inherent. Such differences between GB and Satellite systems (speed, not direction) are fascinating and also await explanation.

iv) Finally ISRs: the ISR - HF/MFR comparisons of Turek et al (JATP vol 57, p1321, 1995) probably represent the last "curtain-call" on AIDA, and we encourage your reading of this fine paper. They show "---the prevailing wind and --- tides --- provide a background wind about which both IDI (HF radar) and ISR winds are normally distributed --- from 70-97 km." These studies also, again, speak to the influence of GW upon all system measurements. There will be an assessment of GW influences upon WINDII/HRDI at Toronto (see below); and more detailed instantaneous line-of-sight comparisons between WINDII - HRDI. That will be fascinating also ---.

The second "Wind Measurements Workshop" is planned for April-May 1996 in Toronto. I am confident that there we will resolve many of these remaining issues involving GB optical/radar and UARS and understand much more of the atmosphere's dynamics in the process - which is surely our interest anyway! The future collaborations involving temporal/spatial studies of waves and wave interactions using radars and UARS are going to be enormously productive in the next 3-5 years. That will carry us through STEP-MLTCS, and into the post-STEP era of S-RAMP and PSMOS, EATVIP years. Exciting and productive years for us all ---

Sincerely Alan Manson