| definition |
-
The Cloud Integrating Nephelometer (CIN) shines a 635 nm laser
beam between two parallel plates that are located outside an
aircraft in the free airstream. The volume of the laser beam
between the plates is 100 cm3. Hydrometeors within the laser
beam scatter light to four Lambertian sensors located within the
instrument plates. The sensors have two domains. The forward
domain lies between 10? and 90?; laser light scattered between
90? and 175? degree falls into the backward domain. Two of the
sensors have ?cosine masks?. These weight the angular
distribution of the intensity of light reaching a sensor by the
cosine of the angle of light scattered by the particle. Thus,
the four channels of the CIN are a forward channel (F), a
backward channel (B), a cosine-weighted forward channel (cF),
and a cosine-weighted backward channel (cB). The fraction of
forward scattered light missed by the sensor (f) has been
precisely calculated to be 0.56 +/- 0.02 for cold cirrus clouds.
[Summary provided by the University of Utah]
|
