초록 ▼

The difficulty of making Doppler shift velocity measurements in a chirp pulse echo ranging system is overcome by employing a pulse frequency compression filter, suitably a SAW compressor 45, having individual outputs 64, 65, 66, 67 respectively relating to adjacent contiguous frequency bands A, B, C

The difficulty of making Doppler shift velocity measurements in a chirp pulse echo ranging system is overcome by employing a pulse frequency compression filter, suitably a SAW compressor 45, having individual outputs 64, 65, 66, 67 respectively relating to adjacent contiguous frequency bands A, B, C, D, (FIG. 3) each having a bandwidth approximately equal to the chirp frequency swing. Signal detection and processing means 70 senses the occurrence of a compressed pulse on any of the outputs and measures the amplitudes of signals on all the outputs. A computer then computes the Doppler shift from the amplitude ratio of the sensed signals to adjacent frequency bands, determines the target velocity therefrom and uses the result also to correct the range measured by the counter 5.

대표청구항 ▼

A chirp pulse echo ranging apparatus comprising transmitting means for emitting pulses of wave energy, each having a frequency which varied linearly during the pulse duration, receiving means for receiving echo signals resulting from reflection of the emitted wave energy from an object, frequency co

A chirp pulse echo ranging apparatus comprising transmitting means for emitting pulses of wave energy, each having a frequency which varied linearly during the pulse duration, receiving means for receiving echo signals resulting from reflection of the emitted wave energy from an object, frequency compression means coupled to the receiving means and having a frequency dispersion characteristic for effecting substantially simultaneous production of components of the received echo signals associated with different predetermined frequencies, thereby forming compressed echo pulses, and timing means for determining a time delay between the occurrence of each compressed echo pulse and a timing reference pulse having a predetermined relationship to a time at which a respective pulse of wave energy was transmitted, characterized in that: a. the frequency compression means includes a plurality of outputs at which ones of said components in different frequency bands are produced; and b. the apparatus includes processing means coupled to said outputs for determining from relative magnitudes of said components a line of sight velocity of the object relative to the apparatus.