Chatter

Chatter may refer to:

See also

Chatter (signals intelligence)

Chatter is a signals intelligence term, referring to the volume (quantity) of intercepted communications. Intelligence officials, not having better metrics, monitor the volume of communication, to or from suspected parties such as terrorists or spies, to determine whether there is cause for alarm. They refer to the electronic communication as "chatter".

Monitoring chatter is an example of traffic analysis, a sub-field of signals intelligence. Intelligence specialists hope to learn significant information by methodically monitoring when and with whom suspects communicate. Even if they cannot decrypt what suspects are saying to one another, a change in the volume of traffic may raise alarm, since a large increase may indicate increased preparation for action, while a sudden decrease may indicate the end of planning and the imminence of action. These considerations do not apply when the targets of analysis follow the military practice of maintaining a steady flow of encrypted communications whether they are needed or not.

Machining vibrations

Machining vibrations, also called chatter, correspond to the relative movement between the workpiece and the cutting tool. The vibrations result in waves on the machined surface. This affects typical machining processes, such as turning, milling and drilling, and atypical machining processes, such as grinding.

A chatter mark is an irregular surface flaw left by a wheel that is out of true in grinding or regular mark left when turning a long piece on a lathe, due to machining vibrations.

As early as 1907, Frederick W. Taylor described machining vibrations as the most obscure and delicate of all the problems facing the machinist, an observation still true today, as shown in many publications on machining.

Mathematical models make it possible to simulate machining vibration quite accurately, but in practice it is always difficult to avoid vibrations and there are basic rules for the machinist: