LFM Pulse
A commonly used radar or sonar pulse is the linear frequency modulated (LFM) pulse (or "chirp"). It has the advantage of greater bandwidth while keeping the pulse duration short and envelope constant. A constant envelope LFM pulse has an ambiguity function similar to that of the square pulse, except that it is skewed in the delay-Doppler plane. Slight Doppler mismatches for the LFM pulse do not change the general shape of the pulse and reduce the amplitude very little, but they do appear to shift the pulse in time. Thus, an uncompensated Doppler shift changes the target's apparent range; this phenomenon is called range-Doppler coupling.
Read more about this topic: Ambiguity Function
Famous quotes containing the word pulse:
“While our pulse beats and we feel emotion, let us put off the business. Things will truly seem different to us when we have quieted and cooled down. It is passion that is in command at first, it is passion that speaks, it is not we ourselves.”
—Michel de Montaigne (1533–1592)