Erta Ale is a remote and rarely visited volcano that is known currently to have an active lava lake in its summit crater. Erta Ale has undergone seven eruption events in the past 125 years.
Re: What are the differences between Signal ground, Chasis ground and Earth?? Signal Ground is a reference point from which that signal is measured, due to the inevitable voltage drops when current flows within a circuit, some 'ground' points will be slightly different to others. There may be several signal grounds in a circuit.
RTTY & Facsimile Equipment. ACARS (Aircraft Communications Addressing and Reporting System) is a radioteletype mode developed in the early eighties as an addressable, digital data link for commercial and business aircraft. It was produced to reduce the flight crew's work-load by using modern computer technology to exchange many routine reports and messages.