WMOD00372

• Project Name: High Plains Cooperative Program
• Title: The Design of HIPLEX-1
• Date: 4/1/1979
• Weather Modification - Doc Type: Report

The Miles City Aero Service cloud survey aircraft (Cessna 414); with-
out special instrumentation will be used to examine cloud development
during situations where a clear-cut decision to launch a research
mission cannot be reached from the ground-based data. During these
marginal situations, the two research aircraft will remain on ~he
ground on a ready-alert status.

B. Radar

The 5.4-cm SWR-75 (Skywater Radar 1975) will be located near the
Miles City airport; the 5.3-cm UNO (University of North Dakota) radar
will be located 125 km east of Miles City at Baker, Montana. Both
these C-band radars were built by Enterprise Electronics, Inc." and
have DVIP (digital' video integrator processors) to convert returned
analog signals to digital values and to record them on 13-mm magnetic
tape.

The SWR-75, built in 1975, has been modified to include a color
display system and a rapid volume-scan capability. Six colors, are
available and may be assigned to any of 14 DVIP levels from -10 dBZ
to +55 dBZ. The time for a full 360. sweep for each of 12 elevation
angles is 3 minutes.

L-band (30-cm) radar systems are incorporated into both the SWR-75
and the UNO radar units to detect transponder-equipped aircraft. Up
to three transponder codes can be entered, and the location of the
aircraft with these codes will be recorded on magnetic tape along
with the cloud video from the C-band system. .

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C. Rawinsonde System

Two rawinsonde systems will be used in HIPLEX-1. Routine observations
are made from Miles City at 0545 and 1330 local time (1145 and 1930
G.m.t.) daily except Sunday. Routine observations are also made from
Baker at 1330 local time (1930 G.m.t.). Observations at 1730 local
time (2330 G.m.t.) are made from both sites when requested by the
site director. Raw rawinsonde data are processed by the Bureau of
Reclamation's CYBER computer in Denver in real time via time-share
computer terminals.

D. Surface Mesoscale Network

Research has indicated the importance of surface mesoscale kin~matics
and dynamics to convective cloud development and propagation. By the
end of the 1979 field season, about 50 mesonet stations will be
installed between Miles City and Baker on an 8 x 6 grid with inter-
station spacing of 20 km. Each station will record temperatur~,

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