JP2000046931A - Radar apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a radar apparatus by which a range profile can be acquired in a short time, by a method wherein a transmission signal is transmitted continuously in a burst shape, and also a local oscillation signal which frequency-converts a bursting echo from a target is outputted in a burst shape. SOLUTION: A transmission-frequency setting signal at the timing of a transmission burst signal and a transmission-reception changeover signal are outputted to an oscillation part 6 by a timing generation part 9. A transmission signal in which a transmission frequency signal from the oscillation part 6 is amplified by a transmission part 5 is transmitted to a space from an antenna part 3 via a transmission-reception changeover part 4. Reflected waves from a target which are received by the antenna part 3 are passed through the transmission-reception changeover part 4, a reception part 7 frequency-converts them by a local oscillation signal in the oscillation part 6, and a generated video signal is converted into a digital signal by an A/D conversion part 8. A band synthesis part 10 analyzes the video signal at reverse frequency so as to generate and display a range profile. At this time, the transmission signal is transmitted in a burst shape, and also the local oscillation signal is output in a burst shape. As result, a plurality of pulse-signals can be transmitted and received at one time.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radar apparatus for acquiring a distance to a target and a range profile thereof by using a band synthesis process for changing a radar transmission frequency in a wide band over a wide band and improving a distance resolution. Things.

[0002]

2. Description of the Related Art FIGS. 6 and 7 show a conventional radar apparatus and an operation diagram. 1 is a radar device, 2 is a target, 3 is an antenna unit that radiates a transmission signal toward the target and receives a reflected wave from the target 2, 4 is a transmission / reception switching unit that switches between a transmission signal and a reception signal by a transmission / reception switching signal, 5 Is a transmitting unit for amplifying a transmission frequency signal, 6 is an oscillating unit for outputting a transmission frequency signal and a local signal according to a transmission frequency setting signal, and 7 is a video signal obtained by frequency-converting, amplifying, and phase-detecting a received signal by a local signal. A receiving unit, 8 is an A / D converting unit for converting a video signal into a digital signal, 9 is a timing generating unit for outputting a transmission / reception switching signal and a transmission frequency setting signal, and 10 is inversely frequency-analyzed and decomposed in the distance direction of the digital signal. A band synthesis unit 11 calculates the target range profile, and a display unit 11 displays the distance to the target and the target range profile.

This operation will be described with reference to FIGS. 6 and 7. FIG. 7A shows the operation, where 1 indicates a radar device, and T1 indicates a target. The frequency of the transmission signal is set in the oscillation unit 6 by the timing generation unit 9 of the radar device 1. The transmission signal is amplified by the transmission unit 5 and radiated toward the target via the transmission / reception switching unit 4 and the antenna unit 3. Transmit signal (b)
Shown in The antenna section 3 receives reflections of the transmission signal pulse examples set at the respective transmission frequencies f1 to fN from the target. The received signal of the target T1 is shown in (c). (D) shows a local signal output from the oscillation unit 6 to the reception unit 7. The received signal is frequency-converted by the local signal from the oscillating unit 6 in the receiving unit 7, then amplified, phase-detected, and converted into a digital signal by the A / D converter. Inverse frequency analysis is performed on the digital signal by the band synthesis unit, and S1 shown in (e) displays a target range profile decomposed in the distance direction of the target T1.

[0004]

In the conventional radar apparatus as described above, as shown in FIG. 7, a radar 1 and a target T1 are set.
When the relative distance R1 is long, the transmission signal f1 is transmitted and R1 is returned to the reception signal until S11 returns as an echo.
Time is needed. In order to display the range profile, it takes time to obtain a reception signal for the transmission signals f1 to fN. If the relative distance is long, it takes a long time to display the range profile. However, there is a problem in that the number of pulses that can hit the target is small and the distance for detecting the target is short.

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem. When a radar apparatus acquires a target distance and a range profile thereof, the acquisition time is shortened, and the target is moved from a long distance. It can be detected and used to display this result.

[0006]

According to a first aspect of the present invention, there is provided a radar apparatus comprising: a timing generator for outputting a transmission / reception switching signal and a transmission frequency setting signal based on a transmission burst signal output from a transmission burst generator; An oscillation unit that outputs a transmission frequency signal and a local signal according to the transmission frequency setting signal, a transmission unit that outputs a transmission signal obtained by amplifying the transmission frequency signal, and a transmission / reception switching unit that switches transmission and reception by the transmission / reception switching signal. An antenna unit that radiates a transmission signal output from the transmission / reception switching unit as a transmission wave toward a target, receives a reflected wave from the target, and outputs a reception signal of the reflected wave received by the antenna unit to a local signal output from an oscillation unit. A receiving unit that outputs a video signal that has been frequency-converted, amplified, and phase-detected by a signal to an A / D conversion unit;
A for converting a video signal from a receiving unit into a digital signal
/ D conversion unit, a band synthesis unit that calculates the target range profile decomposed in the distance direction by performing an inverse frequency analysis of the digital signal, a display unit that displays the range profile, and a transmission burst that outputs a transmission burst signal With a radar device equipped with a generator, a range signal can be transmitted in a short time by continuously transmitting a transmission signal in a burst form, and returning an echo from a target returned in a burst form by oscillating the frequency of a local signal from the oscillation section in a burst form. And means for extending the target detection distance.

A radar apparatus according to a second aspect of the present invention includes a timing generator for outputting a transmission / reception switching signal and a transmission frequency setting signal based on a transmission burst signal output from a transmission burst generator, the transmission / reception switching signal and the transmission frequency. An oscillation unit that outputs a transmission frequency signal and a local signal according to a setting signal; a transmission unit that outputs a transmission signal obtained by amplifying the transmission frequency signal; a transmission / reception switching unit that switches transmission and reception by the transmission / reception switching signal; The output transmission signal is radiated toward the target as a transmission wave,
An antenna unit receiving a reflected wave from a target, and a video signal obtained by frequency-converting, amplifying, and phase-detecting a received signal of the reflected wave received by the antenna unit using a local signal output from an oscillation unit to an A / D conversion unit An A / D converter that converts a video signal from the receiver into a digital signal; a band synthesizer that performs inverse frequency analysis of the digital signal to calculate a target range profile decomposed in the distance direction; A display for displaying the range profile; a relative distance calculator for detecting a target from the digital signal, calculating a relative distance to the target from a time difference between a transmission burst signal and an echo from the target, and outputting a relative distance signal; The transmission burst width is selected so that the next transmission burst signal generated from the relative distance signal and the transmission burst signal does not overlap with the echo from the target. A transmission burst control unit that outputs a transmission burst control signal, and a radar device including a transmission burst generation unit that generates and outputs a transmission burst signal from the transmission burst control signal, continuously transmits the transmission signal in a burst form, The frequency of the local signal is oscillated in burst form from the oscillating unit, and the relative distance is calculated in advance when the echo from the target overlaps the transmission burst signal, and the transmission burst signal is returned according to the distance. , The range profile can be acquired in a short time, the target detection distance can be extended, and the PRI in which the transmission signal and the target echo do not overlap even when the target approaches a short distance can be obtained. Having means.

[0008] Further, the radar apparatus according to the third aspect of the present invention is a radar apparatus comprising:
A timing generation unit that outputs a transmission / reception switching signal and a transmission frequency setting signal according to a PRI setting signal output from an RI control unit; and an oscillation unit that outputs a transmission frequency signal and a local signal according to the transmission / reception switching signal and the transmission frequency setting signal. A transmission unit that outputs a transmission signal obtained by amplifying the transmission frequency signal, a transmission / reception switching unit that switches transmission and reception in accordance with the transmission / reception switching signal, and radiates the transmission signal output from the transmission / reception switching unit as a transmission wave toward a target. An A / D converter converts a video signal obtained by frequency-converting, amplifying, and phase-detecting a received signal of a reflected wave received by the antenna unit into a local delay signal output from a local signal delay unit, and an A / D converter. A receiving section for outputting to the converting section, and an A / A for converting a video signal from the receiving section into a digital signal.
A D conversion unit, a band synthesis unit that performs inverse frequency analysis of the digital signal to calculate a target range profile decomposed in the distance direction, a display unit that displays the range profile, and a PRI signal that detects a target from the digital signal and detects the target. A relative distance calculation unit that calculates a relative distance to the target from a time difference between the target and the echo from the target and outputs a relative distance signal; and a PRI setting signal generated next from the relative distance signal and the PRI setting signal and the target. And a PRI control unit that calculates a PRI and outputs a PRI setting signal so that the echoes do not overlap, and calculates and delays a local signal from the oscillating unit by a relative distance signal and outputs the signal to the receiving unit as a local delay signal. A radar device equipped with a local signal delay unit transmits a transmission signal continuously at short intervals, calculates the relative distance to the target, and calculates the error from the target. By delaying according to the relative distance a local signal over the oscillator in a short time to get the range profile drawing the target detection distance, even approaching a target at a short distance does not overlap the transmission signal and the target echo PR
There is a means to select I and obtain a range profile.

Further, the radar device according to the fourth aspect of the present invention has a P
A timing generator for outputting a transmission / reception switching signal and a transmission frequency setting signal according to a PRI setting signal output from an RI controller, and a local fixed for outputting a transmission frequency signal and a fixed local signal according to the transmission / reception switching signal and the transmission frequency setting signal An oscillating unit, a transmitting unit that outputs a transmission signal obtained by amplifying the transmission frequency signal, a transmission / reception switching unit that switches transmission and reception in accordance with the transmission / reception switching signal, and a transmission signal output from the transmission / reception switching unit is directed to a target as a transmission wave. An antenna unit that radiates and receives a reflected wave from a target, and converts a received signal of the reflected wave received by the antenna unit into a frequency-converted, amplified, and phase-detected video signal by using a local fixed signal output from a local fixed oscillator. A receiving unit for outputting to the A / D converting unit, and an A / D for converting a video signal from the receiving unit to a digital signal The conversion unit calculates the phase difference between the local fixed signal from the local fixed oscillation unit and the transmission frequency according to the relative distance signal calculated by the relative distance calculation unit, corrects the phase of the digital signal, and outputs a corrected digital signal. A phase correcting unit, a band synthesizing unit that performs inverse frequency analysis on the corrected digital signal whose phase has been corrected by the phase correcting unit and calculates a target range profile decomposed in the distance direction, a display unit that displays the range profile, A relative distance calculator for detecting a target from the digital signal, calculating a relative distance to the target from a time difference between the PRI signal and an echo from the target, and outputting a relative distance signal; PRI control unit that calculates the PRI and outputs the PRI setting signal so that the PRI setting signal generated at the time does not overlap the echo from the target A radar device equipped with a transmitter, continuously transmits a transmission signal at a short interval, calculates a relative distance from a target, fixes an echo from the target from an oscillation unit, fixes a local signal from an oscillation unit, and converts a digital signal after A / D conversion into a transmission signal. By using the phase difference between the frequency of the local signal and the frequency of the local signal as a phase, a range profile can be acquired in a short time, the target detection distance can be extended, and even if the target approaches a short distance, the transmission signal and the target echo do not overlap. To obtain a range profile.

The radar apparatus according to a fifth aspect of the present invention provides
A timing generator for outputting a transmission / reception switching signal and a transmission frequency setting signal based on a PRI setting signal output from an RI controller; a transmission frequency signal based on the transmission / reception switching signal and the transmission frequency setting signal; and a local setting signal from a signal detector. A local variable oscillator for outputting a local variable signal, a transmitting unit for outputting a transmission signal obtained by amplifying the transmission frequency signal, a transmission / reception switching unit for switching between transmission and reception by the transmission / reception switching signal, and a signal output from the transmission / reception switching unit. An antenna unit that radiates a transmission signal as a transmission wave toward a target and receives a reflected wave from the target, and converts a reception signal of the reflection wave received by the antenna unit into a local variable signal output from a local variable oscillation unit. A receiving section for outputting the video signal amplified, phase-detected to the A / D conversion section, and a video signal from the receiving section. An A / D converter for converting the signal into a digital signal, a band synthesizer for calculating the target range profile decomposed in the distance direction by performing an inverse frequency analysis on the digital signal, and a display for displaying the range profile. Transmitting a transmission signal of an arbitrary frequency from the digital signal, detecting a signal matching the frequency of the local variable signal, outputting the signal to the local variable oscillating unit by a PRI setting signal from the PRI control unit, and outputting the detection signal to the local variable oscillating unit. A signal detection unit for outputting to the distance calculation unit;
A relative distance calculator for calculating a relative distance to the target from a time difference from an echo from the target from the I setting signal and outputting a relative distance signal; and a PRI setting signal generated next from the relative distance signal and the PRI setting signal That calculates PRI and outputs a PRI setting signal so that the echo from the target does not overlap with the echo from the target
With a radar device equipped with an I control unit, the transmission signal is continuously transmitted at short intervals, the relative distance from the target is calculated, the echo from the target is fixed to the local signal from the oscillation unit at the frequency of the first transmission signal, and The signal detector detects the transmission signal, and then varies the local signal according to the PRI setting signal to acquire the range profile in a short time, extend the target detection distance, and transmit even if the target approaches a short distance. There is a means for selecting a PRI where the signal and the target echo do not overlap and obtaining a range profile.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 FIG. 1 is a configuration diagram showing Embodiment 1 of the present invention. In FIG. 1, a transmission burst generation unit 12 is a new part compared to FIG. 6 which is a conventional configuration diagram. Reference numeral 12 denotes a transmission burst generation unit that sets the timing generation unit 9 so that a transmission signal is not transmitted in a single pulse but a plurality of pulses are transmitted in a burst at a time. Other configurations are the same as those of the related art.

This operation will be described with reference to FIG. In FIG. 1, a transmission burst signal is set from a transmission burst generator 12 to a timing generator 9. A transmission frequency setting signal based on the timing of the transmission burst signal and a transmission / reception switching signal are output from the timing generation section 9 to the oscillation section 6, and the transmission signal amplified by the transmission section 5 from the transmission frequency signal from the oscillation section 6 is transmitted to the transmission / reception switching section 4. Is transmitted from the antenna unit 3 to the space. The reflected wave from the target 2 transmitted to the space is transmitted to the antenna unit 3
The frequency is converted by the receiving unit 7 via the transmission / reception switching unit 4 by the local signal of the oscillating unit 6, and an amplified and phase-detected video signal is generated. The A / D converter 8 converts the video signal into a digital signal, and the received signal corresponding to the different transmission frequency for each pulse transmitted in a burst form is subjected to inverse frequency analysis by the band synthesizer 10 to obtain a range profile. Generate and display. At this time, the transmission signal is transmitted in a burst form by the transmission burst signal, the local signal generated in the oscillation section 6 is also output in a burst form, the frequency conversion is performed in the reception section 7, and the range synthesis section acquires and displays the range profile. Accordingly, a plurality of transmission pulses can be transmitted and received in a burst at a time, so that a range profile can be displayed even in a short time, and the distance for detecting a target can be extended within a certain time.

By adopting such a configuration, FIG.
The problem that it takes time to transmit like the transmission signal (b) when acquiring the target range profile shown in (a) of the operation diagram of FIG. , (D), it is possible to obtain a range profile by setting a local signal. Therefore, the range profile can be acquired and displayed in a short time, and the distance for detecting the target can be extended within a fixed time.

Embodiment 2 FIG. FIG. 2 is a configuration diagram showing a second embodiment of the present invention. 2, a transmission burst generation unit 12, a relative distance calculation unit 13, and a transmission burst control unit 14 are new parts with respect to FIG. 6, which is a conventional configuration. Reference numeral 12 denotes a transmission burst generation unit which sets the timing generation unit 9 so as to transmit a plurality of pulses in a burst at a time, instead of transmitting a transmission signal in a single pulse.
Is a relative distance calculator for detecting a target from a received digital signal and calculating a relative distance to the target from a time difference between a transmission burst signal and a received signal from the target. 14 is a relative distance calculated by the relative distance calculator and a transmission distance. The transmission burst control unit calculates the transmission burst width and controls the transmission burst so that the transmission burst signal generated next from the burst signal does not overlap with the echo from the target. Other configurations are the same as those of the related art.

This operation will be described with reference to FIG. In FIG. 2, a transmission burst signal is set from a transmission burst generator 12 to a timing generator 9. A transmission frequency setting signal based on the timing of the transmission burst signal and a transmission / reception switching signal are output from the timing generation section 9 to the oscillation section 6, and the transmission signal amplified by the transmission section 5 from the transmission frequency signal from the oscillation section 6 is transmitted to the transmission / reception switching section 4. Is transmitted from the antenna unit 3 to the space. The reflected wave from the target 2 transmitted to the space is transmitted to the antenna unit 3
The frequency is converted by the receiving unit 7 via the transmission / reception switching unit 4 by the local signal of the oscillating unit 6, and an amplified and phase-detected video signal is generated. The A / D converter 8 converts the video signal into a digital signal, and the received signal corresponding to the different transmission frequency for each pulse transmitted in a burst form is subjected to inverse frequency analysis by the band synthesizer 10 to obtain a range profile. Generate and display. At this time, the transmission signal is transmitted in a burst form by the transmission burst signal, the local signal generated in the oscillation section 6 is also output in a burst form, the frequency conversion is performed in the reception section 7, and the range synthesis section acquires the range profile. Also, if the target approaches,
By calculating the distance to the target in the relative distance calculation unit to avoid overlapping of the burst transmitted pulse and the received signal from the target, and calculating and setting the next transmission burst width based on the relative distance Since the transmission pulse can be transmitted and received in bursts at a time regardless of the relative distance of the target, the range profile can be displayed even in a short time, and the target detection distance can be extended within a certain time. it can.

Embodiment 3 FIG. 3 is a configuration diagram showing a third embodiment of the present invention. In FIG. 3, a relative distance calculation unit 13 is provided as a new part with respect to FIG.
A PRI control unit 15 and a local signal delay unit 16.
13 detects a target from the received digital signal and
A relative distance calculation unit for calculating a relative distance to the target from a time difference between the setting signal and a reception signal from the target; and a PRI setting signal generated next from the relative distance calculated by the relative distance calculation unit and the PRI setting signal. PRI that calculates PRI so that echoes from the target do not overlap and controls the PRI control signal
The control unit 16 is a local signal delay unit that calculates a delay time of the local signal from the oscillation unit 6 based on the relative distance signal, delays the local signal, and outputs the result to the reception unit 7 as a local delay signal. Other configurations are the same as those of the related art.

This operation will be described with reference to FIG. In FIG. 3, a PRI control signal is set in the timing generator 9 from the PRI controller 15. A transmission frequency setting signal based on the timing of the PRI control signal and a transmission / reception switching signal are output from the timing generation section 9 to the oscillation section 6, and the transmission signal amplified by the transmission section 5 from the transmission frequency signal from the oscillation section 6 is transmitted to the transmission / reception switching section 4. Is transmitted from the antenna unit 3 to the space. The reflected wave transmitted from the target 2 and transmitted to the space is received by the antenna unit 3,
The local signal from the oscillating unit 6 of the local delay unit 16 is frequency-converted by the receiving unit 7 via the transmission / reception switching unit 4 using the local delay signal delayed by the relative distance signal,
Generate an amplified and phase-detected video signal. The video signal is converted into a digital signal by the A / D converter 8, and the received signal corresponding to a different transmission frequency for each pulse transmitted by the shortest PRI is subjected to inverse frequency analysis by the band synthesizer 10 to perform range analysis. Generate and display a profile. At this time, a transmission signal is transmitted for each short PRI by the PRI control signal, a local signal generated by the oscillation unit 6 is also output at a timing for each short PRI, and a local signal is output by the local delay unit 16 according to the relative distance from the target. Is delayed and output, the frequency is converted by the receiving unit 7 and the range profile is acquired by the band synthesizing unit. Further, when the target approaches, the relative distance calculation unit calculates the distance to the target in order to avoid the overlap of the pulse transmitted for each short PRI and the received signal from the target, and transmits the next signal based on the relative distance. By calculating and setting the PRI, it is possible to transmit and receive a plurality of pulses at once as a short PRI regardless of the relative distance of the target, so that the range profile can be displayed even in a short time, and within a certain period of time. The target detection distance can be extended.

Embodiment 4 FIG. 4 is a configuration diagram showing a fourth embodiment of the present invention. In FIG. 4, a relative distance calculation unit 13 is provided as a new part with respect to FIG.
A PRI control unit 15, a local fixed oscillation unit 17, and a phase correction unit 18. A relative distance calculator 13 for detecting a target from the received digital signal and calculating a relative distance to the target from a time difference between a PRI setting signal and a received signal from the target;
Reference numeral 15 denotes a PRI control unit that calculates a PRI from the relative distance calculated by the relative distance calculation unit and the PRI setting signal so that the next PRI setting signal does not overlap with the echo from the target, and controls the PRI control signal. A local fixed oscillator for outputting a transmission frequency signal in accordance with a transmission frequency setting signal from the timing generator 9 and fixing the local signal to a fixed frequency and outputting the signal. Reference numeral 18 denotes a relative frequency between the transmission frequency and the local fixed signal and a target. This is a phase correction unit that calculates a phase difference due to distance and corrects the phase of the digital signal after A / D conversion. Other configurations are the same as those of the related art.

This operation will be described with reference to FIG. In FIG. 4, a PRI control signal is set from the PRI control unit 15 to the timing generation unit 9. The transmission frequency setting signal and the transmission / reception switching signal according to the timing of the PRI control signal are output from the timing generation unit 9 to the oscillation unit 6, and the local fixed oscillation unit 1 is output.
The transmission signal amplified by the transmission unit 5 from the transmission frequency signal from the transmission unit 7 is transmitted to the space from the antenna unit 3 via the transmission / reception switching unit 4. A reflected wave transmitted from the target 2 and received from the target 2 is received by the antenna unit 3, passed through the transmission / reception switching unit 4, converted into a frequency by the local fixed signal from the local fixed oscillation unit 17 by the receiving unit 7, and amplified and phase-detected. Generate The video signal is converted into a digital signal by the A / D converter 8, and the phase difference between the transmission frequency and the local frequency and the phase difference due to the relative distance are calculated to correct the digital signal. The received signal corresponding to the transmission frequency different from the
A range profile is generated and displayed by performing an inverse frequency analysis with 0. At this time, the transmission signal is transmitted for each short PRI by the PRI control signal, frequency conversion is performed by the reception unit 7, and the phase difference between the transmission frequency and the local frequency and the phase difference due to the relative distance are calculated to correct the digital signal.
A range profile is acquired by the band synthesis unit. Further, when the target approaches, the relative distance calculation unit calculates the distance to the target in order to avoid the overlap of the pulse transmitted for each short PRI and the received signal from the target, and transmits the next signal based on the relative distance. By calculating and setting the PRI, it is possible to transmit and receive a plurality of pulses at once as a short PRI regardless of the relative distance of the target, so that the range profile can be displayed even in a short time, and within a certain period of time. The target detection distance can be extended.

Embodiment 5 FIG. 5 is a configuration diagram showing a fifth embodiment of the present invention. In FIG. 5, a relative distance calculation unit 13 is provided as a new part with respect to FIG.
A PRI control unit 15, a local variable oscillation unit 19, and a signal detection unit 20. A relative distance calculator 13 for detecting a target from the received digital signal and calculating a relative distance to the target from a time difference between a PRI setting signal and a received signal from the target;
Reference numeral 15 denotes a PRI control unit that calculates a PRI from the relative distance calculated by the relative distance calculation unit and the PRI setting signal and controls the PRI control signal so that the next PRI setting signal does not overlap with the echo from the target. A local variable oscillator that outputs a transmission frequency signal according to a transmission frequency setting signal from the timing generator 9 and outputs a local variable signal according to a signal detection signal. A local variable signal 20 is constant until the first transmission frequency and signal detection. And a signal detection unit that controls the local variable signal to the local variable oscillation unit 19. Other configurations are the same as those of the related art.

This operation will be described with reference to FIG. In FIG. 5, a PRI control signal is set from the PRI control unit 15 to the timing generation unit 9. The transmission frequency setting signal and the transmission / reception switching signal based on the timing of the PRI control signal are output from the timing generation unit 9 to the local variable oscillation unit 19, and the transmission frequency signal from the local variable oscillation unit 19 is amplified by the transmission unit 5. The signal is transmitted from the antenna unit 3 to the space via the transmission / reception switching unit 4. The reflected wave transmitted from the target 2 and transmitted to the space is received by the antenna unit 3, passed through the transmission / reception switching unit 4, and subjected to frequency conversion by the reception unit 7 using the local variable signal from the local variable oscillation unit 19, and is amplified and phase-detected. Generate The video signal is converted into a digital signal by the A / D converter 8, and a signal that matches the initially set transmission frequency with the initially set local frequency is detected as a signal. The band synthesis unit 10 performs inverse frequency analysis on the received signal corresponding to the different transmission frequency for each of the frequency ranges to generate and display a range profile. At that time, PR
The transmission signal is transmitted every short PRI by the I control signal,
The receiving unit 7 performs frequency conversion, detects that the initially set transmission frequency matches the initially set local frequency as a signal, and detects a local variable signal after the detection as a signal of the frequency setting from the timing generation unit 9. It varies with timing, and a range profile is acquired by the band synthesis unit. Further, when the target approaches, the relative distance calculation unit calculates the distance to the target in order to avoid the overlap of the pulse transmitted for each short PRI and the received signal from the target, and transmits the next signal based on the relative distance. By calculating and setting the PRI, the transmission pulse can be shortened regardless of the relative distance of the target.
Since a plurality of pulses can be transmitted and received at one time, a range profile can be displayed even in a short time, and the target detection distance can be extended within a fixed time.

[0022]

According to the first, second, third, fourth and fifth inventions,
When acquiring the target range profile with the radar device, the transmission pulse is transmitted in bursts or continuously transmitted at short pulse intervals, and by receiving, the range profile can be displayed at high speed regardless of the relative distance. The detection distance can be extended within a certain time.

According to the first aspect of the present invention, compared with the prior art, a transmission pulse is transmitted in a burst and a local signal is generated in a burst following the transmission pulse. Since detection and amplification are performed, a range profile can be displayed at high speed, and the detection distance can be extended within a certain time.

Further, according to the second invention, when the target is located at a short distance, the overlap between the burst transmission pulse and the target reception echo is determined according to the relative distance to the target, as compared with the first invention. By changing the interval between burst transmission pulses, it becomes possible to display a range profile at high speed irrespective of the relative distance to the target, and to extend the detection distance within a fixed time.

According to the third aspect of the present invention, a transmission pulse is continuously transmitted with a shorter PRI as compared with the related art, and a local signal is continuously generated with a shorter PRI following the transmission pulse. Calculate the relative distance to the local signal, set a time delay for the local signal by the relative distance, perform frequency conversion, phase detection, and amplification of the received signal.Furthermore, the overlap between the transmitted pulse and the target received echo is determined according to the relative distance. P
By changing the RI, a range profile can be displayed at a high speed, and the detection distance can be extended within a certain time.

According to the fourth aspect of the present invention, compared to the third aspect of the present invention, transmission pulses are continuously transmitted by a short PRI, a local signal is generated as a local signal having a fixed frequency, and the digital signal is converted into software. The process calculates the relative distance between the target and the phase difference between the transmission frequency and the local frequency, and corrects the phase difference due to the relative distance to a digital signal.
The PRI can be varied according to the relative distance between the transmission pulse and the target reception echo in accordance with the relative distance, and the range profile can be displayed at high speed, and the detection distance can be extended within a certain time.

According to the fifth aspect of the present invention, compared to the third aspect of the present invention, the transmission pulse is continuously transmitted by the short PRI, and the local signal is continuously generated by the short PRI following the transmission pulse. When the local signal matches the transmission frequency at the first frequency and the signal can be detected, the relative distance to the target is calculated, and the local signal is varied with a continuous signal by a short PRI to change the frequency of the local signal. Performs conversion, phase detection, and amplification, and then PRs the overlap between the transmitted pulse and the target received echo according to the relative distance.
By changing I, it becomes possible to display the range profile at high speed, and it is possible to extend the detection distance within a certain time.

[Brief description of the drawings]

FIG. 1 is a diagram showing a first embodiment of a radar apparatus according to the present invention.

FIG. 2 is a diagram showing a second embodiment of the radar device according to the present invention;

FIG. 3 is a diagram showing a third embodiment of the radar device according to the present invention;

FIG. 4 is a diagram showing a fourth embodiment of the radar apparatus according to the present invention;

FIG. 5 is a diagram showing a fifth embodiment of the radar apparatus according to the present invention;

FIG. 6 is a diagram showing a conventional radar device.

FIG. 7 is an operation diagram of the radar device according to the present invention.

[Explanation of symbols]

Reference Signs List 1 radar device, 2 target, 3 antenna unit, 4 transmission / reception switching unit, 5 transmission unit, 6 oscillation unit, 7 reception unit, 8
A / D converter, 9 timing generator, 10 band synthesizer, 11 display, 12 transmission burst generator, 13
Relative distance calculation unit, 14 transmission burst control unit, 15 P
RI control section, 16 local signal delay section, 17 local fixed oscillation section, 18 phase correction section, 19 local variable oscillation section, 20 signal detection section.

Claims (5)

[Claims] 1. A timing generator for outputting a transmission / reception switching signal and a transmission frequency setting signal based on a transmission burst signal output from a transmission burst generator, a transmission frequency signal and a local signal based on the transmission / reception switching signal and the transmission frequency setting signal. An oscillation unit that outputs the transmission frequency signal, a transmission unit that outputs a transmission signal obtained by amplifying the transmission frequency signal, a transmission and reception switching unit that switches transmission and reception by the transmission and reception switching signal, and a transmission signal output from the transmission and reception switching unit as a transmission wave. An antenna unit that radiates toward the target and receives a reflected wave from the target, and a received signal of the reflected wave received by the antenna unit is subjected to frequency conversion by a local signal output from the oscillation unit, amplification, and amplification.
A receiving unit that outputs a video signal subjected to phase detection to an A / D conversion unit, an A / D conversion unit that converts a video signal from the receiving unit into a digital signal, and an inverse frequency analysis of the digital signal to be decomposed in a distance direction. A band synthesizer for calculating a target range profile, a display for displaying the range profile, and a transmission burst generator for outputting a transmission burst signal. 2. A timing generator for outputting a transmission / reception switching signal and a transmission frequency setting signal based on a transmission burst signal output from a transmission burst generator, a transmission frequency signal and a local signal based on the transmission / reception switching signal and the transmission frequency setting signal. An oscillation unit that outputs the transmission frequency signal, a transmission unit that outputs a transmission signal obtained by amplifying the transmission frequency signal, a transmission and reception switching unit that switches transmission and reception by the transmission and reception switching signal, and a transmission signal output from the transmission and reception switching unit as a transmission wave. An antenna unit that radiates toward the target and receives a reflected wave from the target, and a received signal of the reflected wave received by the antenna unit is subjected to frequency conversion by a local signal output from the oscillation unit, amplification, and amplification.
A receiving unit that outputs a video signal subjected to phase detection to an A / D conversion unit, an A / D conversion unit that converts a video signal from the receiving unit into a digital signal, and an inverse frequency analysis of the digital signal to be decomposed in a distance direction. A band synthesizer for calculating the target range profile, a display for displaying the range profile, a target detected from the digital signal, and a relative distance between the target and a transmission burst signal and a time difference between the echo from the target. Calculating a relative distance signal and outputting a relative distance signal, and selecting a transmission burst width so that the next transmission burst signal generated from the relative distance signal and the transmission burst signal does not overlap with the echo from the target, and performing transmission burst control. A transmission burst control unit for outputting a signal, and a transmission burst generation unit for generating and outputting a transmission burst signal from the transmission burst control signal Radar apparatus, comprising the. 3. A timing generator for outputting a transmission / reception switching signal and a transmission frequency setting signal according to a PRI setting signal output from a PRI (pulse repetition cycle) controller, and a transmission frequency according to the transmission / reception switching signal and the transmission frequency setting signal. An oscillation unit that outputs a signal and a local signal, and a transmission unit that outputs a transmission signal obtained by amplifying the transmission frequency signal,
A transmission / reception switching unit that switches between transmission and reception in accordance with the transmission / reception switching signal, an antenna unit that radiates a transmission signal output from the transmission / reception switching unit as a transmission wave toward a target and receives a reflected wave from the target, A receiver for outputting a video signal obtained by frequency-converting, amplifying, and phase-detecting the received signal of the reflected wave by the local delay signal output from the local signal delay unit to an A / D converter, and converting the video signal from the receiver into a digital signal An A / D converter for converting the signal into a signal,
A band synthesizing unit for calculating a range profile of a target resolved in a distance direction by inverse frequency analysis of the digital signal, a display unit for displaying the range profile, a PRI signal for detecting a target from the digital signal and an echo from the target A relative distance calculation unit that calculates a relative distance to the target from a time difference between the PRI setting signal and a relative distance calculation unit that outputs a relative distance signal, and that the PRI setting signal generated next from the relative distance signal and the PRI setting signal does not overlap the echo from the target. PRI and PR
A PRI control unit for outputting an I setting signal; and a local signal delay unit for calculating and delaying a local signal from the oscillation unit to a relative distance signal, calculating a delay time, and outputting the delayed signal as a local delay signal to a receiving unit. A radar device characterized by the above-mentioned. 4. A timing generator for outputting a transmission / reception switching signal and a transmission frequency setting signal according to a PRI setting signal output from a PRI control unit, and a transmission frequency signal and a frequency fixed by the transmission / reception switching signal and the transmission frequency setting signal. A local fixed oscillator that outputs a fixed local signal, a transmitter that outputs a transmission signal obtained by amplifying the transmission frequency signal, a transmission / reception switching unit that switches transmission and reception by the transmission / reception switching signal, and a signal output from the transmission / reception switching unit. An antenna unit that radiates a transmitted signal as a transmission wave toward a target and receives a reflected wave from the target, and a received signal of the reflected wave received by the antenna unit is used as a frequency by a local fixed signal output from a local fixed oscillation unit. A receiving unit that outputs the converted, amplified, and phase-detected video signal to an A / D conversion unit; and a video signal from the receiving unit. A / that converts the signal to a digital signal
A phase difference between the D conversion unit and the local fixed signal from the local fixed oscillation unit and the transmission frequency is calculated according to the relative distance signal calculated by the relative distance calculation unit, and the corrected digital signal is output by correcting the phase of the digital signal. A phase correction unit,
A band synthesizing unit for calculating the target range profile decomposed in the distance direction by performing an inverse frequency analysis of the corrected digital signal whose phase has been corrected by the phase correcting unit, a display unit for displaying the range profile, and detecting the target from the digital signal A relative distance calculator for calculating a relative distance to the target from a time difference between the PRI signal and an echo from the target and outputting a relative distance signal; and a PRI setting signal generated next from the relative distance signal and the PRI setting signal. And a PRI control unit for selecting a PRI so that echoes from the target do not overlap and outputting a PRI setting signal. 5. A timing generator for outputting a transmission / reception switching signal and a transmission frequency setting signal according to a PRI setting signal output from a PRI control unit, and a transmission frequency signal and a signal detection unit according to the transmission / reception switching signal and the transmission frequency setting signal. A local variable oscillator for outputting a local variable signal in accordance with a local setting signal from the transmitter, a transmitter for outputting a transmission signal obtained by amplifying the transmission frequency signal, a transmission / reception switching unit for switching between transmission and reception in accordance with the transmission / reception switching signal, An antenna unit that radiates a transmission signal output from the unit as a transmission wave toward a target and receives a reflected wave from the target,
A receiving unit that outputs a video signal obtained by frequency-converting, amplifying, and phase-detecting a received signal of a reflected wave received by the antenna unit using a local variable signal output from a local variable oscillation unit to an A / D conversion unit; A / D converter for converting the video signal into a digital signal, a band synthesizer for calculating a target range profile decomposed in the distance direction by performing an inverse frequency analysis of the digital signal, and a display for displaying the range profile Transmitting a transmission signal of an arbitrary frequency from the digital signal and detecting a signal that matches the frequency of the local variable signal, and after detection, outputs the signal to the local variable oscillating unit by a PRI setting signal from the PRI control unit and outputs a detection signal. A signal detector for outputting to the relative distance calculator, and a target based on a time difference between the detection signal and an echo from the target based on the PRI setting signal. A relative distance calculator for calculating a relative distance and outputting a relative distance signal; selecting a PRI from the relative distance signal and the PRI setting signal so that the next PRI setting signal does not overlap with the echo from the target; And a PRI control unit that outputs a signal.