Transcript IOM-87_Module_B2_6.pps

DISTROMETER
TURKEY AWOS TRAINING 1.0 / ALANYA 2005
DISTROMETER
A Distrometer is an instrument that
measures the size of raindrops. There are
many different types of distrometer.
TURKEY AWOS TRAINING 1.0 / ALANYA 2005
The 2D-Video-Distrometer
• It records two side view optical images of each
rain drop. For this reason it is called a 2D-Video-
Distrometer or 2DVD for short.
TURKEY AWOS TRAINING 1.0 / ALANYA 2005
• The 2D-Video-Distrometer is a newly developed ground
based point monitoring precipitation gauge, working on
the basis of video cameras. Originated in the area of
weather radar and tropospheric wave propagation
research, the 2D-Video-Distrometer is designed to meet
the needs generally of anybody interested in details on
precipitation.
TURKEY AWOS TRAINING 1.0 / ALANYA 2005
•
The measurements reveal classification of precipitation
at measurement site as well as full particular on single
hydrometeors. Such comprehensive data have not been
available up to now. Of each raindrop, snowflake
hailstone reaching the measuring area, the front view,
the side view and the velocity are measured and
recorded. The resolution of the digitizing grid is in the
order of 0.25 mm. For a reliable classification of
precipitation events distributions of size and velocity of
particles as well as of oblateness of drops are generated
in real time. Of course the rainrate is given.
TURKEY AWOS TRAINING 1.0 / ALANYA 2005
Instrument functions
• Monitors precipitation.
• Identifies precipitation type (rain, snow, hail, drizzle..).
• Provides hydrometeor size distribution (for drops,
snowflakes, hailstones); this is called disdrometric
function.
• Measures instantaneous rainfall rate.
• Gives the total rainfall in a given time interval.
TURKEY AWOS TRAINING 1.0 / ALANYA 2005
• The knowledge of hydrometeor size distribution
(disdrometric function) is crucial in investigating,
or forecasting, such events and occurrences as
soil erosion and percolation, landslides,
evapotranspiration, plant physiology, spring
seepage etc., or in several other applications,
such as in meteorological radar calibration, in
defining reflectivity vs rainfall rate relationships,
etc..
TURKEY AWOS TRAINING 1.0 / ALANYA 2005