This permits users to monitor signal levels and stage noise, in addition to identify spurious signals and signal frequencies. Basically, the RF spectrum analyzer can be used to measure signals we understand (our very own transmitters or electric equipment), or to monitor and identify telltale signs that we don't already know.
There are two chief varieties of spectrum analyzer: analog and digital spectrum analyzer. Nearly all spectrum analyzers in the marketplace now are digital, even though there are still analog analyzers available on the market. Since RF congestion continues to worsen, an increasing number of spectrum analyzer consumers are understanding the demand for electronic sweeps, and so are starting to recognize that what they really need is real time spectrum analysis. Luckily for them, real-time spectrum analyzers (sometimes only known as "RTSA") are more popular today than ever, providing immediate real time visualization of the RF environment without needing human sweeps.