In radio astronomy, a spectrograph which correlates the signal with itself with various time delays, and extracts the frequency spectrum of the signal. → correlator.
hambâzângar-e calipâyi, ~ xâji
In radio interferometry, a device that multiplies together the signals received by each pair of antennas in an array and performs several operations on the signal (filtering out the noise added to the signal by the receiver electronics, correcting for the Doppler shift and geometric delay due to the position and motion of the antennas). The correlated signal, corresponding to the spatial frequency given by the distance between the two antennas, is then combined with the other spatial frequency to reconstruct the map of the source.
Fr.: autocorrélateur optique
An instrument used to test lenses by utilizing the → optical transfer function. It consists of a HeNe laser, a beamsplitter and two mirrors.