GMDSS Maintainer: Element 9

1. A A measure used that compares the distance of a desired signal to the level of background noise.
2. B A measure used that compares the level of a desired signal to the level of background noise.
3. C A measure used that compares the frequency of a desired signal to the frequency of background noise.
4. D A measure that measures signal in the forward direction and noise in the reverse direction.

Tip: press A-D to answer