1) Measuring device 2) Measuring instrument 3) Measuring system 
Nephoscope is an instrument for measuring the altitude, direction, and velocity of clouds. There are several types of nephoscopes: Also a type of nephoscope was invented by Mikhail Pomortsev in 1894 in Russia. The nephoscope is used as a grid to measure the clouds.It is also used to find the movements of clouds. A ray of light of known velocity is...
instrument for observing direction and velocity of clouds
• (n.) An instrument for observing the clouds and their velocity. • (n.) An instrument for observing the clouds and their velocity.
Neph'o·scope noun [ Greek ... a cloud + -scope .] (Meteorol.) An instrument for observing the clouds and their velocity. 
A nephoscope is an instrument used in observing the altitude and motion of clouds.
[n] - a grid-like measuring instrument for measuring the altitude, direction, and velocity of movement of clouds
nephoscope An instrument for observing and determining the direction and velocity of clouds in motion.
noun a measuring instrument that uses a grid for measuring the altitude, direction, and velocity of movement of clouds
an instrument for determining the speed and direction of cloud motion.