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If the instrument stands on level ground, so that the observer's eye is always at the same height, and if the interval between two successive spikes is equal to one-tenth of their altitude above the eye-level of the observer, one only needs to multiply the time required for the cloud to pass over one interval by 10 to determine the time the ...
A pyranometer is a type of actinometer used to measure broadband solar irradiance on a planar surface and is a sensor that is designed to measure the solar radiation flux density (in watts per metre square) from a field of view of 180 degrees. A ceilometer is a device that uses a laser or other light source to determine the height of a cloud ...
A ceilometer is a device that uses a laser or other light source to determine the height of a cloud ceiling or cloud base. [1] Ceilometers can also be used to measure the aerosol concentration within the atmosphere. [2] A ceilometer that uses laser light is a type of atmospheric lidar (light detection and ranging) instrument. [3] [4]
Nephelometer – an instrument used to measure suspended particulates in a liquid or gas colloid. Gas-phase nephelometers are used to provide information on atmospheric visibility and albedo; Nephoscope – an instrument for measuring the altitude, direction, and velocity of clouds
cloud base The lowest altitude of the visible portion of a cloud. cloud bow See fogbow. cloud cover The obscuration of all or part of the sky by clouds as observed from a particular location, or the specific fraction of the sky obscured by clouds as measured in oktas. cloud drop effective radius cloud genus See cloud type. cloud iridescence ...
The observer looks through the eyepiece and sets the sight onto the spot projected on the cloud and reads the height from the attached scale. When the cloud is thin the beam of light may penetrate into the cloud. The observer should read the scale where the light first enters the cloud and not at the top.
The first weather satellite, Vanguard 2, was launched on February 17, 1959. [4] It was designed to measure cloud cover and resistance, but a poor axis of rotation and its elliptical orbit kept it from collecting a notable amount of useful data. The Explorer 6 and Explorer 7 satellites also contained weather-related experiments. [3]
Scattering by particulates impairs visibility much more readily. Visibility is reduced by significant scattering from particles between an observer and a distant object. The particles scatter light from the sun and the rest of the sky through the line of sight of the observer, thereby decreasing the contrast between the object and the ...