Vaisala IRIS, User Manual

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3.3 BASE : Echo Base Product
Figure 3 BASE Example Configuration
BASE is used to determine the base of echoes.
Similar to the echo TOPS , the user specifies a dBZ Contour for the base. For each output
pixel in the product, the algorithm searches downward through successive elevation angles.
A base height is determined by linear interpolation when the specified
dBZ Contour is
crossed from greater to lesser value.
The final output of the product is a color-coded map of echo base heights for the selected
dBZ contour. Optional Cartesian smoothing can be applied.
C, S and X band radars detect precipitation particles such as rain or snow. They are not
sensitive to cloud particles which are much smaller (of order a factor of 1000 smaller in
diameter). The
BASE product cannot be used to detect the cloud base height for radars
transmitting in these bands.
Millimeter wavelength radars (K and W bands) can detect cloud particles.
IRIS Product and Display User Guide M211319EN-H
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