AM: Air Monitor Aps do not support user connectivity. They are dedicated to constantly scan the radio environment, gathering Intrusion Detection System (IDS) and Layer 2 information. Like Rogue APs etc.
SA: Spectrum APs have been setup (temporarily or permanently) to capture radio singals for analysis. APs that gather spectrum data across all operation channels, but to not service clients, are called Spectrum Monitors (SM). APs that DO service clients and also gather spectrum data on the channel of operation are said to be operating in hybrid mode.