airports

I know that some of the VOLMET channels (aviation weather) will send out a QSL but how about ATC chatter? I have been able to catch some local ATIS broadcasts from nearby airports but wasn't to sure about ATC communications.

I'm starting to get into listening to aircraft radio. Most airports have frequencies for Approach, Departure, Tower, and Ground. I understand the first two. What is tower and ground for? Should I try to monitor those frequencies if I'm not close to the airport? I live in southeast Alabama, and...

Does anyone know if airports care about you bringing (and using) scanners to the gate and on the plane? I'm new, so go easy on me, any answer is appreciated!!