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II II II II II II II II I I I I I I I I I I I 5. Draw boundaries of "area of effect" based on 3 or 4 above. Figure 11 is an example of the area of effect eompu- tations. The time hilstory of the PPI echoes are displayed. In this' case the cloud layer wind had little variation and thus the plume computation was straightforward. The University of Delawarl3 group were provided area-of-effect maps for each of the Experimental Period case studies, shortly after the completion of the field opera- tiops. These areas were then utilized in the raingage studies. 4. 2 Airborne Data and Observations Two basic data sets were available for analysi.s. First, was the computer printouts of the airborne sensor data and second, the voice tapes which recorded the pilot/co-pilot obs.erva- tions. For each of the Case study days, cloud observations were reviewed to determine the general characteristics of thle cloud parameters. Values of liquid water content (average and maximum for a given pass) were obtained from the airborne tapes and plotted on the PPI overlays at the location of the aircraft penetration. Estimates of the updraft speeds were derived from altitude changes and rate-of-climb readings recorded on the voice tapes. It should be noted that the ice particle concentration unit was inoperative for most of the season, thus the type and amount of ice in the cloud was estimated from observations made by the pilot and recorded on voice tapes. The airborne data were utilized in characteriz:ing the cloud conditions at the time of seeding. These data contributed to the interpretation of cloud physical processes occurring in the initiation and generation of precipitation fallout. 35 '-