canal à bande étroite

CONT: The basic defect of the receiving system was its high sensitivity to the reverberation generated by the set’s very high power transmissions and the use of rapid scanning to achieve omnidirectional coverage on a single transmission. This effectively precluded the separation of reverberation and noise backgrounds during processing. The only solution to this problem lay in the use of preformed receiving beams (as in Type 177), which allowed this separation, and, indeed, allowed parallel processing of narrow-band channels (cross-correlation or matched-filter processing) to reduce detection threshold and extract [Doppler] information.