Radio frequency generators, why "pulse option" is needed?

[fk0]

Some frequency generators has "pulse option", when radio frequency can be generated in bursts with configured pulse length from tens of nanoseconds.  What is reason for existing such mode, why it can be useful?

I suppose, that such mode can be useful in some setups for some form of measurements, but which exact?  Moreover, how "pulse option" can be useful if generator has neither external trigger input, nor trigger output (for spectrum analyzer, etc...)  So generation of pulses cannot be synchronized with other equipment.

Also, frequently generators has the option to modulate (AM or ON/OFF keying) radio frequency with low (audio) frequency. So radio frequency can be modulated with square wave by ON/OFF keying. Why such type of modulation cannot be used instead of "pulse option"?

How generator with "pulse option" can be useful for amateur ham radio practice?

[jonpaul]

burst testing

radar modulation

not intened for Amateur Radio

j

[czorgormez]

tdr -  time domain reflectometry

[David Hess]

Power measurements often cannot be made continuously because of power dissipation limitations, so a pulsed RF signal is used instead, which is essentially the same as a radar application.