Pulse-Pair Method

Take two consecutive pulses and measure the phase of the received pulses as shown in the schematic to the right -->>

Recall that:

(1)

where df=f₂-f₁

dt = time between pulses

dr/dt = radial velocity of the target = V

so:

(2)

but df/dt is really the angular velocity = w = 2pf_d

So, (2) becomes:

or:

How does the radar then measure f_d?