User`s guide

User's Guide ______________________________________________________________________
24 __________________________________________________________________ M210455EN-B
CT25KAM employs pulsed diode laser LIDAR (Light Detection and
Ranging) technology for cloud detection, precipitation, and other
obstructions to vision, and accurate cloud heights and vertical
visibility determination.
The standard measurement range of CT25KAM extends up to 25 000
feet (7.5 km) covering most heights where dense clouds appear. The
instrument is capable of reporting up to three cloud layers
simultaneously. It detects the cloud base reliably in fog, rain, snow,
and haze. If the cloud base is obscured, CT25KAM measures and
reports vertical visibility.
Extensive internal monitoring is supported by a comprehensive set of
user commands that can be given locally or remotely. Internal
monitoring includes a sensor measuring the outgoing laser pulse
energy, circuitry checking the receiver sensitivity, a sensor monitoring
window contamination, and two sensors measuring the tilt angle.
These and other internal measurements are used by the diagnostics
software and the detection algorithm for maximum reliability and ease
of use.
A special additional tilt sensor is provided as standard for
automatically compensating uneven terrain. Installation is made easy
and fast when no exact leveling is required. The cloud coverage
algorithm in the CT25KAM is a further development of the algorithm
specified by FAA. Cloud coverage (amount) is reported in 0 to 8
octas, according to WMO regulations.
Present Weather Detector PWD11A
0306-021
Figure 13 Present Weather Detector PWD11A
Present Weather Detector PWD11A is an intelligent multivariable
sensor for automatic weather observing systems. The sensor combines
the functions of a forward scatter visibility meter and a present