Process for measuring the ambiguous distance and pulse Doppler radar using such a process
AssigneeThomson-CSF
InventorMichel Prenat
Life of this patent
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Abstract
The present invention relates to a process for measuring the ambiguous distance in a pulse Doppler radar of repetition frequency (f.sub.R). The device comprises means (3) for transposing the signal received R(t) by a signal of frequency p.multidot.f.sub.R, where p is a positive integer; first and second narrow band filtering means (2,5) isolating the principal line of the signal received R(t) and of the transposed signal d(t) respectively, and means (6) for measuring the phase difference (.DELTA..phi.) which exists between the two filtered signals and which is proportional to the ambiguous distance with a coefficient g.
Claims9
A process for measuring the ambiguous distance in a tracking Doppler radar transmitting pulses at a repetition frequency f.sub.R, and receiving signals reflected by a target in a reception window, comprising successively:
- a first step of transposing to a same frequency the principal line and a side line of order p in the frequency spectrum of the received signal, p being a positive integer;
- a second step of measuring the phase difference between the transposed principal and side lines at the same frequency;
- and
- a third step of multiplying the phase difference measured by a coefficient for providing a measurement of the ambiguous distance corresponding to the target.
A Doppler radar transmitting pulses at a repetition frequency f.sub.R by means of an antenna and receiving, by means of the same antenna, the signal reflected by the target and split by a reception window, further comprising:
- means for transposing a side line of order p, p being a positive integer, and the principal line of the signal received to a same frequency,
- first and second narrow band filtering means for isolating respectively the principal line of the signals which are delivered by the transposing means, and with which they are respectively supplied;
- means for measuring the phase difference existing between the signals at the same frequency delivered by the first and second filtering means and delivering a signal (.DELTA..phi.) whose amplitude is proportional to the ambiguous distance of the target.
Dependencies are inferred from the claim text.