JP2008089469A - Radar device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a radar device that can achieve attenuation processing of a received signal with relatively easy circuitry and is easily adjusted. <P>SOLUTION: The attenuation processing of the received signal is shared and executed by a level attenuation section 152 of a signal processing device 15 without depending only on an STC (Sensitivity Time Control) circuit 141, it is not necessary to gradually decrease the attenuation amount over the detection distance in the STC circuit 141, and the received signal is attenuated for each divided time range of an STC control signal 1 based on the fixed value thereof. The attenuation amount set by the level attenuation section 152 is controlled so that it varies at a constant gradient to time change. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a radar apparatus used for, for example, aircraft approach / departure control.

  Conventionally, radar devices such as ASR (Airport Surveillance Radar) have been used at airports in various regions in order to control the approach / departure of aircraft such as passenger aircraft (for example, Non-Patent Document 1).

This radar apparatus detects and tracks the flight position of an aircraft by transmitting radar waves to an aircraft about to land and receiving and detecting radar reflected waves from the aircraft.
Radar technology The Institute of Electronics, Information and Communication Engineers.

  By the way, in the receiving device of the radar apparatus, an appropriate signal level is attenuated by an STC (Sensitivity Time Control) circuit for the purpose of preventing saturation of the high frequency amplifier, and the aircraft passes through the high frequency amplifier and the frequency converter. The signal is input to a signal processing device that detects the target of the target. The attenuation amount of the STC circuit is controlled by the STC control signal so as to be larger than the received signal at a short distance, and the attenuation amount is decreased with a constant slope as the distance increases.

  However, the STC control signal input to the STC circuit needs to be gradually changed with a certain inclination with respect to the time axis, and analog adjustment is required when it is realized by a hardware circuit. Further, it is necessary to arbitrarily change the attenuation amount of the circuit (component) that realizes the STC circuit, and further, quick response to the STC control signal is required, so that the circuit (component) to be configured is limited. .

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a radar device that can realize attenuation processing of a received signal with a relatively easy circuit configuration and that can be easily adjusted.

  In order to achieve the above object, the present invention transmits a radar wave, receives a reflected wave of the radar wave, and passes the received signal through an attenuation unit that can arbitrarily control the attenuation amount. The signal is converted into a digital signal and processed, and the attenuation control unit becomes the maximum attenuation for the received signal at the maximum short distance within the detection distance, and the attenuation is gradually reduced with a predetermined inclination to the maximum detection distance. In a radar apparatus that generates one control signal and controls the attenuation amount of the attenuation unit based on the first control signal, a level attenuation unit that attenuates the signal level of the digital signal by an arbitrary attenuation amount, and a first control The signal is divided into a plurality of time ranges, a second control signal having a constant attenuation amount for each time range and reducing the attenuation stepwise is generated. Based on the second control signal, the attenuation unit 1st control hand which controls attenuation And a second control for generating a third control signal corresponding to the difference between the first control signal and the second control signal, and controlling the attenuation amount of the level attenuating unit based on the third control signal. Means.

  According to this configuration, it is possible to perform the attenuation process of the received signal by sharing the level attenuation unit without depending on only the attenuation unit, and it is necessary to gradually change the attenuation amount over the detection distance in the attenuation unit. There is no need to attenuate the received signal based on the fixed value for each divided time range. For this reason, the structure of the attenuation part can be simplified, and the adjustment becomes easy. In addition, the amount of attenuation set in the level attenuation section needs to change with a certain slope with respect to time change, but since it is a process for digital signals, it can be realized by software calculation and adjustment is not required. It becomes.

  The first control means is characterized in that an attenuation amount is arbitrarily variably set based on input data for a time range corresponding to a specific area in the second control signal.

  According to this configuration, for example, a constant attenuation amount can be set to a large attenuation amount for an area having a fixed clutter.

  The first control means includes a storage medium storing waveform data of the second control signal, and the second control means includes a storage medium storing waveform data of the third control signal. And

  According to this configuration, since the first and second control means can be configured by a circuit using a storage medium, a simple and excellent response circuit can be provided.

  As described above in detail, according to the present invention, it is possible to provide a radar apparatus which can realize attenuation processing of a received signal with a relatively easy circuit configuration and can be easily adjusted.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
(First embodiment)
FIG. 1 is a block diagram showing the configuration of the radar apparatus according to the first embodiment of the present invention. In FIG. 1, reference numeral 1 denotes a radar device, which includes an antenna device 11, a circulator 12, a transmission device 13, a reception device 14, and a signal processing device 15. A transmission wave generated by the transmission device 13 is radiated from the antenna device 11 to the space via the circulator 12. The received wave reflected by a target such as an aircraft is received by the antenna device 11 and then supplied to the receiving device 14 via the circulator 12.

  In the receiving device 14, the received signal is attenuated at an appropriate signal level by the STC circuit 141, amplified by low noise by the high frequency amplifier 142, and then frequency-converted by the frequency converter 143 to a received intermediate frequency signal. It is supplied to the signal processing device 15.

  The signal processing device 15 includes an A / D (Analog / Digital) conversion unit 151, a level attenuation unit 152, a signal processing unit 153, and an STC control generation unit 154. The received intermediate frequency signal is converted into a digital signal by the A / D conversion unit 151, the appropriate signal level is attenuated by the level attenuation unit 152, and the target target is detected by the signal processing unit 153.

  The STC control generator 154 outputs an STC control signal (1) and an STC control signal (2) for setting an attenuation amount. The STC circuit 141 sets the attenuation amount according to the STC control signal (1), and the level attenuation unit 152 sets the attenuation amount according to the STC control signal (2).

  FIG. 2 shows the relationship between the amount of attenuation of the STC circuit 141 and time (distance). That is, the STC control signal (1) changes stepwise with respect to time.

  FIG. 3 shows the relationship between the amount of attenuation of the level attenuation unit 152 and time (distance). That is, the attenuation amount of the STC control signal (2) decreases with a constant inclination with respect to the time change.

  The STC control generation unit 154 is provided with a storage unit 1541 that stores the waveform data of the STC control signal (1) and a storage unit 1542 that stores the waveform data of the STC control signal (2).

  Next, operation in the above configuration will be described.

  Previously, the radar apparatus 2 having the configuration shown in FIG. 4 has been considered. In FIG. 4, the same parts as those in FIG.

  A transmission wave generated by the transmission device 13 is radiated from the antenna device 11 to the space via the circulator 12. The received wave reflected by a target such as an aircraft is received by the antenna device 11 and then supplied to the receiving device 14 via the circulator 12.

  As shown in FIG. 5, this transmission / reception operation is repeated at 360 ° time division. In this case, the STC control generator 155 supplies an STC control signal as shown in FIG. 6 to the STC circuit 141 so as to control the attenuation amount of the STC circuit 141.

  However, in the radar device 2, the STC control signal input to the STC circuit 141 needs to be gradually changed with a certain inclination with respect to the time axis, and analog adjustment is necessary when realized by a hardware circuit. Become. In addition, the circuit (component) that realizes the STC circuit 141 also needs to vary the attenuation amount arbitrarily, and also requires quick response to the STC control signal, so that the circuit (component) to be configured is limited. End up.

  Therefore, in the present embodiment, the level attenuator 152 is inserted and connected between the A / D converter 151 and the signal processor 153 of the signal processing device 15, and the STC control signal is divided into a plurality of time ranges. The STC control signal (1) having a constant attenuation amount for each of the divided time ranges and being reduced in steps is supplied to the STC circuit 141, and corresponds to the difference between the STC control signal and the STC control signal (1). The STC control signal (2) to be supplied is supplied to the level attenuator 152.

  Thereby, the attenuation amount realized by the STC circuit 141 may be a certain fixed value, and it is only necessary to realize a stepwise change with a constant value with respect to a time change, and the circuit to be configured can be simplified. Adjustment is also easy.

  In addition, the attenuation set by the level attenuation unit 152 requires a change with a certain inclination with respect to a change with time. However, since it is a process for a digital signal, it can be realized by software calculation and can be adjusted. There is no need to do.

  In the conventional method, since it is realized by a hardware circuit, analog adjustment is required. Further, it is necessary to arbitrarily change the attenuation amount of the circuit (component) that realizes the STC circuit 141, and STC control. Since a quick response to a signal is also required, the circuit (component) to be configured is limited. However, in the present embodiment, the request to the circuit (component) to be configured by dividing the function is not relatively limited, and Adjustment can also be facilitated.

  As described above, in the first embodiment, the attenuation process of the received signal is executed by being shared by the level attenuation unit 152 of the signal processing device 15 without relying only on the STC circuit 141, and the detection is performed in the STC circuit 141. There is no need to gradually reduce the attenuation over the distance, and the received signal is attenuated based on the fixed value for each divided time range of the STC control signal (1). Therefore, the configuration of the STC circuit 141 can be simplified and the adjustment can be facilitated. Further, the attenuation amount set in the level attenuating unit 152 needs to change with a certain inclination with respect to the time change. However, since it is a process for a digital signal, it can be realized by software calculation and can be adjusted. It becomes unnecessary.

  In the first embodiment, the STC control generator 154 uses the storage unit 1541 that stores the waveform data of the STC control signal (1) and the storage unit 1542 that stores the waveform data of the STC control signal (2). Therefore, it is possible to provide a simple and excellent responsive circuit.

(Second Embodiment)
FIG. 7 is a block diagram showing a configuration of a radar apparatus according to the second embodiment of the present invention. In FIG. 7, the same parts as those of FIG.

  In the second embodiment, an area setting unit 156 is provided for the STC control generation unit 154. The area setting unit 156 can arbitrarily set an attenuation amount for a specific area (defined by a distance and a direction).

  That is, the operator uses the area setting unit 156 to attenuate the waveform data of the STC control signal (1) stored in the storage unit 1541 with respect to the area where the fixed clutter or the like exists as shown in FIG. Rewrite to increase the amount. Further, the waveform data of the STC control signal (2) stored in the storage unit 1542 may be rewritten so as to change as shown in FIG.

  Thus, according to the second embodiment, it is possible to set a constant attenuation amount to a large attenuation amount in an area where fixed clutter or the like exists.

(Other embodiments)
Although the present invention has been described based on each embodiment, the present invention is not limited to the above-described embodiments as they are, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. Moreover, various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the above embodiments. For example, some components may be deleted from all the components shown in each embodiment.

1 is a block diagram showing a configuration of a radar apparatus according to a first embodiment of the present invention. The characteristic view which shows the relationship between the attenuation amount of STC circuit and time (distance) in the said 1st Embodiment. The characteristic view which shows the relationship between the amount of attenuation of a level attenuation part, and time (distance) in the said 1st Embodiment. The block diagram which shows the structure of the radar apparatus considered before. The figure shown in order to demonstrate the transmission / reception operation | movement of the radar wave of a radar apparatus. The characteristic view which shows the relationship between the attenuation amount of STC circuit and time (distance) in the former radar apparatus. The block diagram which shows the structure of the radar apparatus concerning 2nd Embodiment of this invention. The characteristic view which shows the relationship between the attenuation amount of STC circuit, and time (distance) in the said 2nd Embodiment. The characteristic view which shows the relationship between the attenuation amount of a level attenuation part, and time (distance) in the said 2nd Embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1, 2 ... Radar apparatus, 11 ... Antenna apparatus, 12 ... Circulator, 13 ... Transmission apparatus, 14 ... Reception apparatus, 15 ... Signal processing apparatus, 141 ... STC circuit, 142 ... High frequency amplification part, 143 ... Frequency conversion part, 151 ... A / D conversion unit, 152 ... level attenuation unit, 153 ... signal processing unit, 154,155 ... STC control generation unit, 156 ... area setting unit, 1541, 1542 ... storage unit.

Claims (3)

A radar wave is transmitted, a reflected wave of the radar wave is received, and the received signal is passed through an attenuation unit that can arbitrarily control the attenuation amount, converted into a digital signal by the processing unit, and signal processing is executed. Then, the attenuation control unit generates a first control signal which becomes the maximum attenuation amount for the reception signal at the maximum short distance within the detection distance and gradually decreases the attenuation amount with a predetermined inclination to the maximum detection distance. In a radar apparatus that controls the attenuation amount of the attenuation unit based on a signal,
A level attenuation unit for attenuating the signal level of the digital signal by an arbitrary attenuation amount;
The first control signal is divided into a plurality of time ranges, and a second control signal having a constant attenuation amount for each time range and stepwise decreasing the attenuation amount is generated. First control means for controlling the amount of attenuation of the attenuation unit based on;
Generating a third control signal corresponding to the difference between the first control signal and the second control signal, and controlling the amount of attenuation of the level attenuation unit based on the third control signal; And a radar device. The radar apparatus according to claim 1, wherein the first control unit arbitrarily variably sets an attenuation amount based on input data for a time range corresponding to a specific area in the second control signal. . The first control means includes a storage medium storing waveform data of the second control signal,
The radar apparatus according to claim 1, wherein the second control unit includes a storage medium in which waveform data of the third control signal is stored.

Images