WMOD00429

• Title: Devloping Techniques for Measuring Precipitation
• Date: 4/18/1978
• Weather Modification - Doc Type: Report

Two Automatic Environmental Surface Observation Platforms (AESOP's)
were tested on the SCPP during the past winter, see figure 4. The
AESOP's collect data on precipitation, wind speed, wind direction,
temperature, humidity, and pressure and transmit it hourly via the
GOES satellite and an interconnected link of computers to the project
personnel in less than 15 minutes. The favorable comparisons made
this winter with existing data collection systems at Blue Canyon and
the Central Sierra Snow Laboratory have provided the basis for
increasing the system to three sites and placing them in remote
locations next winter. The AESOP's are an improvement over the
ERTS/LANDSAT platforms used in the San Juans, since the frequency of
data availability is better suited to project operations.

V. Conclusions

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The measurement of preci pitati on and especi ally snowfall conti nues
to be a developing technology. Continued research and innovation
are required to provide reliable, high resolution, spatial and
temporal data. The best data possible are essential to both the
operation and evaluation of weather modification projects. Project
Skywater has made a contribution to the progress and will continue
to support promising efforts.

The recording precipitation gage is a basic evaluaticln tool for
discriminating the changes in precipitation during a randomized
seeding program. Acceptance by the public of change$ in precipita-
tion resulting from cloud seeding is strongly dependl:!nt on physical
measurements of either precipjtation or runoff.

Although radar can provide an estimation of precipitcltion over a
large area, the magnitudes of the radar estimates ha',e not been
shown to be accurate enough to provide the sole means for evaluation
of seeding experiments. It is believed that a combination of radar
and precipitation gages may provide the best estimatl:!s.

The ability to relay data has taken enormous strides in recent
years. Innovations such as circuit boards, miniaturiized computers,
microprocessors, and satellites have pushed the qualiity of data
transmission ahead at a faster rate than the quality of data
measurements.

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With the most careful application of the methods and equipment
available today, it is possible to obtain useful precipitation data
for the operation and evaluation of randomized cloud seeding programs.
However, the rewards for further development and improvement are
great, and everyone with an interest in the field should support the
research and development necessary to real ize those ,"ewards.

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