At the comparison of the echos between two or more pulse periods the fall can appear, that the airplane flies with exactly this one radial speed, some a phase shifting of correct 360 causes. In accordance with the periodicity of the sine function this fall can appear even at all integral multiples of n 360. The phase shiftings value is zero in these falls too. Well, the target isn't recognized as a moving target therefore. It flies with a so called blind speed and and the MTI system won't report it like a ground clutter.

The blind speed is dependent on the transmitted frequency and on the pulse repetition frequency of the radar unit.


Bild 1: Zusammenhang Dopplerfrequenz und Blindgeschwindigkeit

Figure 1: Blind speed in connexion with the Doppler-shift
vblind = λ

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2Ts
vBlind = one of the blind speeds
λ = wavelength of the transmitted pulse
Ts = pulse repe ...more

Not since Don DeLillo and George Saunders has a writer caught the humor and irreverent seriousness of our time like Barkan has through his protagonist Paul Berger, a flawed hero whose so-called fate drives him toward enlightenment just as surely as it propels him to destruction. Berger is stunned when he receives an ominous palm reading from a savvy guru at a health retreat in Iowa, of all places. And now it seems the prophecy is coming true. His fiancee, who is about to leave him, is shot at a historic reenactment of the Revolutionary War in Concord. One of his brothers, an astronaut, dies on 9/11 in the Pentagon. And his more famous brother, a lawyer and politician, kidnaps him in a media campaign to win an election. But is Paul's life really controlled by fate? Or is the prophecy a lie he has latched onto ever since his band went under, leaving him almost famous yet unknown--a teacher at a community college, struggling to keep his job?
Blind Speed is a wildly entertaining explora ...more

A speed at which v can't control.....
for example if u r drivig a bike at the speed of 150kms in a very dense area then u can't controle it......