Laserfiche WebLink
<br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br /> <br />each was equipped with a DR! remotely controlled generator (see Huggins, 1994), an automatic <br />propane dispenser (see Super et aI., 1995), and an automated meteorological station which <br />monitored \\ind. temperature, humidity, and icing. The DR! generators burned an AgI-l'..'H}-acetone <br />mixture. and released AgI at a rate of 22 g h-:. Manual silver iodide generators developed at <br />y10ntana State Uni\'ersity iMSC) were also available for use at either site. The MSU generators <br />burned the same silver iodide mixture, but their release rates were 30 g h-l of AgL Tests at the <br />Colorado State Cloud Simulation Laboratory have indicated both generators produced a contact-type <br />ice nucleant (Dey10n et at.. 1983). A third type of silver iodide generator used in the 1994 field <br />program \\-as another manual type operated by NA we at ~~leY-baSed sites upwind of the <br />Wasatch Plateau. These also burned the same AgI mixture, but at a rate of 8 g h-I. Seeding <br />experiments described in this report made use of either the DR! or MSU generators at the high <br />altitude sites. <br /> <br />The high altitude (2982 m) radar-radiometer site (RRS in Fig. 1) was equipped with the <br />CSBR microwave radiometer, the Utah-DR! scanning Ka-band radar, an automated weather station <br />(\\ind, temperature, humidity, and icing), and an NC\R ice nucleus counter. The DRI acquired files <br />of the standard meteorological data and NCAR counter data from the USBR in files of 6-min <br />averages. Data from the radiometer ".'ere acquired after being processed by the USBR in Denver into <br />daily files of 2-min averages. <br />The radar was operated only during active seeding experiments, or during clear weather <br />chaff tracking experiments. The DR! was responsible for the radar data collection and processing, <br />and the details of its operational periods are found in Huggins ( 1994). Radar data were archived on <br />site on 8 mm tapes in an hourly file structure. In post-processing, the radar data were displayed in <br />the playback mode of the data acquisition computer and individual scans were captured by screen <br />grabber software for printing or detailed temporal analysis. These raw data were displayed in units <br />of recei\'ed power (dBM). Two radar calibrations were performed on the receiver and ar:tenna <br />system during the field program. These calibrations related receiver digital counts to power and are <br />displayed in Fig. 3. <br />From the characteristics of the radar a radar constant was computed. To convert power to <br />radar reflectivity factor ( dBZ), a radar equation for the 1994 field program was developed as: <br /> <br />7 <br />