The phrase "faint signals" means that there are very quiet or weak messages or signs that are hard to notice or understand.
Sentences with «faint signals»
Our stations offer superb accuracy and can pick up faint signals from billions of kilometres away. (esa.int)
This is a particularly exciting band because it allows astronomers to detect faint signals of water in the nearby Universe. (eso.org)
It is hoped that the JWST will be able to record extremely faint signals from very young galaxies (a feat that has yet to be reached). (spaceflightinsider.com)