JP6641805B2 - Polarimetric SAR device and observation method - Google Patents

Description

  The present invention relates to a polarimetric SAR apparatus and an observation method using a synthetic aperture radar (SAR), and more particularly, to a polarimetric SAR apparatus and an observation method for performing polarimetric SAR observation and moving object detection observation.

  In the field of remote sensing using a flying object such as an artificial satellite or an aircraft, a synthetic aperture radar (SAR) using microwaves is used as a sensor for imaging the state of the earth's surface. Synthetic aperture radar is a radar that can obtain high resolution as an antenna that combines a virtually large aperture by utilizing the Doppler effect due to the movement of an antenna mounted on a flying object. Note that the “ground surface” to be sensed includes the “sea surface”.

  Polarimetry (polarization analysis) in SAR data analysis is a technique for measuring characteristics of an observation target using transmission / reception radar information of different combinations of polarizations. The polarization of the radio wave is reflected with a unique change depending on the surface condition. Using this property, the ground surface can be observed with two radio waves having different polarizations, and the reflected signal in each case can be measured to identify the target in detail. In recent years, polarimetric SAR observations utilizing the polarization information of this radio wave have attracted attention.

  In polarimetric SAR observation, the polarization of radio waves transmitted from the SAR is alternately switched between horizontal polarization (H polarization) and vertical polarization (V polarization) for each transmission pulse, and when receiving reflected waves from the ground surface, , H polarization and V polarization simultaneously. Thus, four types of polarization combinations (H polarization transmission / H polarization reception, H polarization transmission / V polarization reception, V polarization transmission / H polarization reception, V polarization transmission / V polarization reception ) Observation data can be obtained.

  That is, the observation data of the H polarization and the V polarization received when the H polarization is transmitted are expressed as H polarization transmission / H polarization reception and H polarization transmission / V polarization reception, respectively. The observation data of the H polarization and the V polarization received when transmitting the V polarization is expressed as V polarization transmission / H polarization reception and V polarization transmission / V polarization reception, respectively. Note that H-polarization transmission / H-polarization reception is HH, H-polarization transmission / V-polarization reception is HV, V-polarization transmission / H-polarization reception is VH, and V-polarization transmission / V Polarization reception is also referred to as VV.

  Since the reflection from the ground surface changes the polarization characteristics depending on the difference in the surface state, by performing polarimetric SAR observation, it is possible to evaluate the difference in the surface state and generate an image from the observation data. In particular, since HV and VH are almost the same observation data among the four types of polarization combinations, they are generated from three types of observation data with other polarization combinations (HH, VV). A pseudo color image can be generated by assigning three types of red, blue, and green to each of the obtained images. This pseudo-color image has significantly improved the discrimination ability in polarimetric SAR observation.

  Patent Document 1 is a prior art document relating to such polarimetric SAR observation. Patent Literature 1 discloses an invention of a polarimetric SAR image processing apparatus capable of reproducing a clear image in accordance with a target. The technique disclosed in Patent Literature 1 changes an angle A of a plane of polarization of a transmission wave and an angle B of a plane of polarization of a reception wave, thereby forming an image at the angles of the planes of polarization of the transmission wave and the reception wave that most clearly show the target. Is configured to be played.

  Here, a configuration example of a polarimetric SAR device and an output example of observation data as background art according to Patent Document 1 and the like will be described with reference to FIGS. 15 and 16.

  FIG. 15 is a block diagram showing a configuration of a polarimetric SAR device in the background art.

  Polarimetric SAR device 500 includes an H-polarization antenna 511, a V-polarization antenna 512, a circulator 521, 522, a switch 530, a transmitter 540, two receivers 551 and 552, a controller 560, a recording unit 570, and an image processing device. 580.

  The H polarization antenna 511 transmits and receives H polarization. The V polarization antenna 512 performs transmission and reception of V polarization. The circulators 521 and 522 correspond to the H-polarization antenna 511 and the V-polarization antenna 512, and switch between transmission and reception for each.

  Transmitter 540 outputs a transmission signal.

  The receiver 551 receives the reception signal of the H polarization antenna 511, and the receiver 552 receives the reception signal of the V polarization antenna 512.

  The controller 560 outputs a PRI (Pulse Repetition Interval: pulse repetition interval) trigger for switching the transmission polarization and controls each device.

  The switch 530 switches the transmission polarization for each transmission pulse by the PRI trigger. Note that the PRI trigger from the controller 560 is also supplied to the transmitter and the receiver, but is not shown in order to avoid complication.

  The recording unit 570 records data output by the receivers 551 and 552 as observation data. The image processing device 580 generates and outputs a polarimetric SAR image from the observation data.

  FIG. 16 is a diagram illustrating a combination of the observation data sequence 1 output from the receiver 551 and the observation data sequence 2 output from the receiver 552 in response to the operation of the switch 530.

  In the above configuration, as shown in FIG. 16, HH and VH observation data are alternately output from the receiver 551 for each PRI (observation data sequence 1). That is, H-H of the H-polarization signal received by the H-polarization antenna 511 at the time of H-polarization transmission transmitted from the H-polarization antenna 511, and H-H at the time of V-polarization transmission transmitted from the V-polarization antenna 512. This is VH of the H polarization signal received by the polarization antenna 511.

  Then, as shown in FIG. 16, the HV and VV observation data are alternately output from the receiver 552 for each PRI (observation data sequence 2). This is because the V-polarized signal received from the V-polarized antenna 512 at the time of H-polarized transmission transmitted from the H-polarized antenna 511 and the V-polarized signal transmitted from the V-polarized antenna 512 are transmitted. This is the V-V of the V-polarized signal received by the V-polarized antenna 512.

  These observation data are recorded by the recording unit 570, and the image processing device 580 generates a pseudo color SAR image from the HV or VH and the three types of observation data of HH and VV as described above. Generate.

  On the other hand, research on moving object detection (MTI: Moving Target Indicator) by SAR has recently been made.

  A system that uses two antennas is often used in moving object detection. In this method, two antennas are arranged in the traveling direction of an aircraft or satellite equipped with a SAR, transmission is performed from one antenna, and reception is performed simultaneously by the two antennas. As a result, the received observation data is the same as that obtained by performing a slight time difference observation, and the ground surface is moved by techniques such as Along Track Interferometry (ATI) and Displaced Phase Center Antenna (DPCA). It can detect the body and measure its speed.

  FIG. 17 is a block diagram showing a configuration of a SAR device having a moving object detection function in the background art.

  In a polarimetric SAR device 501 having this moving object detection function, an MTI antenna (F) 513 and an MTI antenna (A) 514 are arranged in the traveling direction of an aircraft or satellite. Here, F means installation at the front (Forward), and A means installation at the rear (Afterward).

  Other components include a circulator 523, a transmitter 541, two receivers 553 and 554, a controller 561, a recording unit 571, and an image processing device 581.

  The circulator 523 switches between transmission and reception for the MTI antenna (F) 513.

  FIG. 18 is a diagram illustrating a combination of the observation data sequence 1 output from the receiver 551 and the observation data sequence 2 output from the receiver 552 of the SAR device 501 having the moving object detection function.

  From the receiver 553, observation data (denoted by FF) transmitted from the MTI antenna (F) 513 as the observation data sequence 1 and received by the MTI antenna (F) 513 is output for each PRI. The receiver 554 transmits observation data (noted as FA) transmitted from the MTI antenna (F) 513 as the observation data sequence 2 and received by the MTI antenna (A) 514 for each PRI.

  The observation data sequence 1 and the observation data sequence 2 are recorded by the recording unit 571, and a moving object detection image is generated by the image processing device 581. Since there is a time difference between the observation image data generated from the observation data sequence 1 of FF and the observation image data generated from the observation data sequence 2 of FA, the moving object can be detected.

  Patent Document 2 is a prior art document relating to a technique for detecting a moving object using SAR. Patent Literature 2 discloses an invention relating to a radar device that detects a low-speed moving target in a radar device that observes with high resolution by a synthetic aperture radar (SAR) method using a plurality of polarizations. In Patent Document 2, azimuth compression processing or the like is performed on an artificial fixed target, an artificial moving target, a natural fixed target, and a radar echo from the natural moving target, and the like. Extract radar echo. By utilizing that the radar echo from the artificial moving target is much stronger than the radar echo from the natural moving target, the artificial moving target is detected from the natural moving target.

JP 2008-014735 A JP 2004-219292 A

  Since the polarimetric SAR observation function and the moving object detection function require different observation data, if they are to be implemented simultaneously, the size of the device and the observation data to be recorded / processed will increase compared to the SAR with each function alone. There was a problem that.

  FIG. 19 is a block diagram illustrating a configuration example of a polarimetric SAR device according to the background art in a case where the polarimetric SAR observation function and the moving object detection function are simultaneously implemented. FIG. 20 is a diagram showing a combination of a switch operation and observation data in the polarimetric SAR device.

  The polarimetric SAR device 502 that simultaneously realizes the polarimetric SAR observation function and the moving object detecting function has a configuration of a moving object detecting function of a hatched portion surrounded by a dotted line added to the configuration of the polarimetric SAR device 500 shown in FIG. That is, the number of antennas is increased by two to four, and the number of receivers is also increased by two to four, and the hardware scale of the apparatus is increased. In addition, since the number of receivers is doubled, the generated observation data is also doubled as shown in FIG.

  Further, neither the invention disclosed in Patent Document 1 nor the invention disclosed in Patent Document 2 intends to simultaneously realize the polarimetric SAR observation function and the moving object detection function.

  The present invention provides a polarimetry SAR device and an observation method capable of simultaneously realizing a polarimetry SAR observation function and a moving object detection function while suppressing an increase in the scale of the device and observation data to be recorded / processed.

  In order to achieve the above object, a polarimetric SAR device according to one embodiment of the present invention is an antenna of a synthetic aperture radar (SAR), and at least one of the antenna surfaces is divided into two. H / A antennas for transmitting / receiving H-polarized light and V-polarized antennas for transmitting / receiving V-polarized light, which are Σ / Δ antennas disposed before and after in the traveling direction, and transmitting H-polarized light for each transmission pulse. A first switch for switching to V polarization transmission, and a difference (Δ) signal received by a first polarization antenna that is the Σ / Δ antenna, which is one of the H polarization antenna and the V polarization antenna. A second switch that switches a sum (Σ) signal received by the other second polarization antenna for each transmission pulse, and outputs the transmission pulse in synchronization with the first switch and the second switch. control A first step of receiving a Δ signal received by the first polarization antenna and a Σ signal received by the second polarization antenna corresponding to the transmission pulse, and outputting a first observation data sequence A second receiver that receives a Σ signal received by the first polarization antenna in response to the transmission pulse and outputs a second observation data sequence; The first data used for polarimetry observation and the second data used for mobile object detection are selected from the sequence and the second observation data sequence, a polarimetric SAR image is generated from the first data, and the second data is generated. Image processing means for generating a moving object detection image from the image data.

  An observation method according to another embodiment of the present invention is an antenna of a synthetic aperture radar (SAR), wherein at least one of the antenna surfaces is divided into two and the antenna surfaces are arranged in front and rear in the traveling direction. The transmission signal is transmitted to the H-polarized antenna for transmitting and receiving H-polarized light and the V-polarized antenna for transmitting and receiving V-polarized light, which are あ る / Δ antennas, using the first switch to transmit H-polarized light and The transmission is switched to polarization transmission, and the difference (Δ) signal received by the first polarization antenna, which is the Σ / Δ antenna of one of the H polarization antenna and the V polarization antenna, and the other A second switch switches a sum (Σ) signal received by the two polarization antennas for each transmission pulse with a second switch, and outputs the transmission pulse in synchronization with the first switch and the second switch. Δ received by one polarization antenna And the second polarization antenna receives the Σ signal corresponding to the transmission pulse to output a first observation data sequence, and the 偏 signal received by the first polarization antenna transmits the Σ signal. The second observation data sequence is output in response to the pulse, and the first observation data sequence and the second observation data sequence are used for first data used for polarimetry observation and second data used for mobile object detection. Data, a polarimetric SAR image is generated from the first data, and a moving object detection image is generated from the second data.

  According to the present invention, the polarimetric SAR observation function and the moving object detection function can be simultaneously realized while suppressing an increase in the scale of the apparatus and observation data to be recorded / processed.

FIG. 2 is a diagram illustrating a principle configuration of a Σ / Δ antenna used in the present invention. FIG. 1 is a block diagram illustrating a configuration of a polarimetric SAR device according to a first embodiment of the present invention. FIG. 3 is a flowchart showing an operation of the polarimetric SAR device according to the first embodiment of the present invention. It is a block diagram showing the composition of the polarimetry SAR device of a 2nd embodiment of the present invention. It is a block diagram showing the composition of the image processing device of the polarimetric SAR device of the second embodiment of the present invention. FIG. 9 is a flowchart illustrating an operation of the polarimetric SAR device according to the second embodiment of the present invention. It is a figure showing a combination of observation data in a polarimetry SAR device of a 2nd embodiment of the present invention. It is a block diagram showing the composition of the polarimetry SAR device of a 3rd embodiment of the present invention. It is a figure showing a combination of observation data in a polarimetry SAR device of a 3rd embodiment of the present invention. It is a block diagram showing the composition of the polarimetry SAR device of a 4th embodiment of the present invention. It is a figure showing a combination of observation data in a polarimetry SAR device of a fourth embodiment of the present invention. It is a block diagram showing the composition of the polarimetry SAR device of a 5th embodiment of the present invention. It is a figure showing a combination of observation data in a polarimetry SAR device of a 6th embodiment of the present invention. It is a figure showing a combination of observation data in a polarimetry SAR device of a seventh embodiment of the present invention. It is a block diagram showing the composition of the polarimetry SAR device in the background art. FIG. 16 is a diagram showing a combination of the observation data sequence 1 and the observation data sequence 2 output according to the operation of the switch of the polarimetric SAR device in FIG. 15. FIG. 11 is a block diagram illustrating a configuration of a SAR device having a moving object detection function according to the background art. FIG. 18 is a diagram illustrating a combination of an observation data sequence 1 and an observation data sequence 2 output according to the operation of a switch of the SAR device having the moving object detection function in FIG. 17. It is a block diagram which shows the example of a structure of the polarimetric SAR apparatus in the background art at the time of trying to implement | achieve simultaneously the polarimetric SAR observation function and the moving body detection function. FIG. 20 is a diagram illustrating a combination of a switch operation and observation data of the polarimetric SAR device in FIG. 19.

  Most applications of polarimetric SAR observation are in outputting polarimetric SAR images as pseudo-color images. By considering the following technical features, the present invention realizes a SAR device that simultaneously realizes a polarimetric SAR observation function and a moving object detection function while suppressing an increase in the size of the device and observation data to be recorded and processed. I do.

  As one of the configurations for realizing the above, a Σ / Δ antenna having two antenna surfaces divided into two vertically or horizontally is used as a configuration for acquiring observation data for detecting a moving object.

  In the present invention, the Σ / Δ antenna is used in such a manner that the two divided antenna surfaces are arranged before and after in the traveling direction (see the principle configuration in FIG. 1).

  The front antenna surface in the traveling direction is referred to as an antenna surface (F), and the rear antenna surface is referred to as an antenna surface (A). At the time of signal transmission, a sum signal (Σ signal = F + A) using both antenna surfaces is transmitted, and at the time of reception, a sum signal (Σ signal) and a difference signal (Δ signal = FA) are received, respectively. . In the following description, the sum signal may be simply referred to as Σ or Σ signal, and the difference signal may be simply referred to as ま た は or 信号 signal.

  By using such a Σ / Δ antenna, two types of observation data of Σ transmission / Σ reception (Σ−Σ) and Σ transmission / Δ reception (Σ−Δ) can be obtained. Then, by taking the sum and difference of these two types of observation data, it is possible to generate two pieces of observation image data obtained by performing time difference observation, and it is possible to detect a moving object.

  Then, at least one of the H-polarized antenna and the V-polarized antenna may be a Σ / Δ antenna.

  Further, a switch is provided for switching and outputting two types of received signals, a Δ signal received by the Σ / Δ antenna and a Σ signal received by the other polarization antenna, for each transmission pulse.

  For example, when the V-polarized antenna is a Σ / Δ antenna, upon reception, the above-described switch switches between the H-polarized wave received Σ signal and the V-polarized wave received Δ signal. As a result, two sets of transmission pulses are set as one set, and H-polarized {transmit / H-polarized} receive (H-H), H-polarized {transmit / V-polarized} receive (H-V), V-polarized Observation data of {transmission / V polarization Δreception (VΣ−VΔ), V polarizationΣtransmission / V polarizationΣreception (VΣ−V}) can be obtained.

  Then, these observation data are used as data for generating a polarimetric SAR image and data for generating a moving object detection image.

  For example, observation data of HΣ-HΣ, HΣ-VΣ, and VΣ-VΣ are used as data for polarimetric SAR image generation. Further, the observation data of VΣ−VΣ and VΣ−VΔ are used as data for generating a moving object detection image as V polarization antenna Σ signal reception data and V polarization antenna Δ signal reception data, respectively.

  An embodiment for carrying out the present invention will be described below in detail with reference to the drawings.

  Note that the embodiment is an exemplification, and the disclosed apparatus and method are not limited to the configurations of the following embodiment.

(First embodiment)
The configuration of the polarimetric SAR device according to the first embodiment of the present invention will be described.

  FIG. 2 is a block diagram showing a configuration of the polarimetric SAR device according to the first embodiment of the present invention.

  The polarimetric SAR device 10 according to the first embodiment includes an H polarization antenna 111, a V polarization antenna 112, a first switch 121, a second switch 122, a first receiver 131, a second receiver 132, It comprises a control means 140 and an image processing means 150.

  The H-polarized antenna 111 and the V-polarized antenna 112 are synthetic aperture radar (SAR) antennas, at least one of which is a Σ / Δ antenna. Respectively.

  As described above, the Δ / Δ antenna includes two antennas (F and A) divided into front and rear along the traveling direction, and transmits a sum (Σ) signal of F + A during transmission and receives Time is an antenna that receives the Σ signal of F + A and the difference (Δ) signal of F−A, respectively.

  The first switch 121 switches the transmission signal between H polarization transmission and V polarization transmission for each transmission pulse.

  The second switch 122 receives the difference (Δ) signal received by the first polarization antenna, which is one of the 偏 / Δ antennas, one of the H polarization antenna 111 and the V polarization antenna 112, and the other second polarization antenna. The sum (Σ) signal received by the wave antenna is switched for each transmission pulse. In FIG. 2, V-polarized antenna 112 is illustrated as a Σ / Δ antenna, V-polarized antenna 112 corresponds to a first polarized antenna, and H-polarized antenna 111 corresponds to a second polarized antenna.

  The control unit 140 outputs the transmission pulse in synchronization with the first switch 121 and the second switch 122.

  The first receiver 131 converts a Δ signal received by the first polarization antenna (V polarization antenna 112) and a Σ signal received by the second polarization antenna (H polarization antenna 111) into a transmission pulse. And outputs the first observation data sequence.

  The second receiver 132 receives the Σ signal received by the first polarization antenna (the V polarization antenna 112) in response to the transmission pulse, and outputs a second observation data sequence.

  The image processing means 150 selects first data used for polarimetry observation and second data used for moving object detection from the first observation data sequence and the second observation data sequence. Then, a polarimetric SAR image is generated from the first data, and a moving object detection image is generated from the second data.

  The operation of the polarimetric SAR device according to the first embodiment configured as described above will be described.

  FIG. 3 is a flowchart showing the operation of the polarimetric SAR device according to the first embodiment of the present invention.

  A transmission signal is transmitted to a H-polarization antenna for transmitting and receiving H-polarized light and a V-polarization antenna for transmitting and receiving V-polarized light by a first switch for each transmission pulse. The transmission is switched between wave transmission and V polarization transmission (S101). Here, at least one of the H-polarized antenna and the V-polarized antenna is a Σ / Δ antenna in which two divided antenna surfaces are arranged in front and behind in the traveling direction.

  The sum (Σ) of the difference (Δ) signal received by the first polarization antenna, which is one of the Δ / Δ antennas of the H polarization antenna and the V polarization antenna, and the reception (が) received by the other second polarization antenna The signal is switched for each transmission pulse by the second switch (S102).

  The transmission pulse is output in synchronization with the first switch and the second switch (S103).

  The Δ signal received by the first polarization antenna (Σ / Δ antenna) and the Σ signal received by the second polarization antenna are received corresponding to the transmission pulse, and the first observation data sequence is output (S104). ).

  The Σ signal received by the first polarization antenna (Σ / Δ antenna) is received corresponding to the transmission pulse and the second observation data sequence is output (S105).

  First data used for polarimetry observation and second data used for moving object detection are selected from the first observation data sequence and the second observation data sequence (S106).

  A polarimetric SAR image is generated from the first data, and a moving object detection image is generated from the second data (S107).

  As described above, in the present embodiment, the Δ signal received by the first polarization antenna, which is the Σ / Δ antenna, and the Σ signal received by the second polarization antenna are switched by the second switch for each transmission pulse. To obtain the first observation data sequence. Further, the second observation data sequence is configured to obtain a Σ signal received by the first polarization antenna (Σ / Δ antenna) corresponding to a transmission pulse.

  For example, if the V-polarized antenna is a Σ / Δ antenna as a first polarized antenna and the H-polarized antenna is a second polarized antenna, the following observation data sequence is obtained.

  As the first observation data sequence, H polarization {transmission / H polarization {reception data (H} −H}) and V polarization {transmission / V polarization Δ reception data (V 観 測 −VΔ) are obtained. Further, H-polarized {transmit / V-polarized} receive data (H-V) and V-polarized {transmit / V-polarized} receive data (V-V) are obtained as second observation data strings.

  From these acquired data, HΣ-H し て, HΣ-VΣ, and VΣ-VΣ can be selected to generate a polarimetric SAR image. Also, V 移動 -VΣ and VΣ-VΔ are selected, and a moving object detection image can be generated as V-polarized antenna Σ signal reception data and V-polarization antenna 信号 signal reception data, respectively.

  Even when the H-polarized antenna is the first polarized antenna and the V-polarized antenna is the second polarized antenna, the polarimetric SAR observation data and the mobile object detection observation data can be obtained in the same manner.

  In this case, V-polarizationΣtransmission / V-polarizationΣreception data (VΣ−VΣ) and H-polarizationΣtransmission / H-polarization Δreception data (HΣ−HΔ) are obtained as the first observation data sequence. In addition, V polarization {transmission / H polarization} reception data (V-H) and H polarization {transmission / H polarization} reception data (H-H) are obtained as the second observation data sequence.

  From these acquired data, V し て -VΣ, VΣ-HΣ, and HΣ-HΣ can be selected to generate a polarimetric SAR image. Further, it is possible to select HΣ−HΣ and HΣ−HΔ, and generate a mobile object detection image as H-polarized antenna Σ signal reception data and H-polarized antenna Δ signal reception data, respectively.

  As described above, in the present embodiment, by using at least one of the H-polarized antenna and the V-polarized antenna as a Σ / Δ antenna, both data necessary for polarimetric SAR observation and data required for mobile object detection are obtained. Can be obtained. As an additional configuration required for that, it is sufficient to provide a switch for switching between the Δ signal received by the Σ / Δ antenna and the Σ signal received by the other antenna. The acquired data necessary for polarimetric SAR observation and the data necessary for mobile object detection are appropriately selected and used, so even if polarimetric SAR observation and mobile object detection observation are performed simultaneously, the total amount of observation data Does not increase. Therefore, as compared with the configuration shown in FIG. 19, the increase in the number of antennas and the number of receivers can be suppressed, and the increase in observation data can be suppressed.

  As described above, in the present embodiment, the polarimetric SAR observation function and the moving object detection function can be simultaneously realized while suppressing the scale of the apparatus and the increase in observation data to be recorded and processed.

(Second embodiment)
Next, a second embodiment of the present invention will be described.

  FIG. 4 is a block diagram showing a configuration of the polarimetric SAR device according to the second embodiment of the present invention.

  The polarimetric SAR device 20 according to the second embodiment includes an H-polarized antenna 211 and a V-polarized antenna 212, a switch 221, a switch 222, a receiver 231, a receiver 232, and a transmitter 240. Further, the polarimetric SAR device 20 includes a control unit 250, an image processing device 260, a recording unit 270, and a circulator 281.

  The H-polarization antenna 211 and the V-polarization antenna 212 are synthetic aperture radar (SAR) antennas for performing H-polarization transmission / reception and V-polarization transmission / reception, respectively. Antenna.

  As described above, the Δ / Δ antenna includes two antennas (F and A) divided into front and rear along the traveling direction, transmits an F + A Σ signal during transmission, and F + A during reception.ア ン テ ナ signal and the Δ signal of FA are received by the antenna.

  The switch 221 switches the transmission signal output from the transmitter 240 between H polarization transmission and V polarization transmission for each transmission pulse by a PRI trigger.

  The switch 222 switches a Δ signal received by the V-polarized antenna 212, which is a Σ / Δ antenna, and a Σ signal received by the H-polarized antenna 211, for each transmission pulse by a PRI trigger.

  The circulator 281 switches transmission and reception of a signal to each antenna.

  The control unit 250 outputs a PRI trigger for switching the transmission polarization and controls each device. The control unit 250 outputs the PRI trigger in synchronization with the switches 221 and 222. The PRI trigger from the control unit 250 is also supplied to the transmitter 240 and the receivers 231 and 232, but is not illustrated in order to avoid complication.

  Further, the control unit 250 controls the transmission polarization type output from the switch 221 and the reception polarization type output from the switch 222 to be the same. That is, when the switch 221 transmits the H polarization, the switch 222 receives the H polarization, and when the switch 221 transmits the V polarization, the switch 222 receives the V polarization. To control.

  The recording unit 270 records the received observation data and transfers it to the image processing unit 260 at the same time.

  FIG. 5 shows the configuration of the image processing device 260.

  FIG. 5 is a block diagram showing a configuration of the image processing device 260 of the polarimetric SAR device 20.

  The image processing device 260 includes three functional units that perform a separation process 261, a polarimetric SAR image process 262, and a moving object detection process 263. In the separation process 261, an observation data sequence 1 and an observation data sequence 2 including a combination of observation data to be described later are input and distributed to a polarimetry observation data sequence and a mobile object detection (MTI) observation data sequence. In the polarimetric SAR image processing 262, a polarimetric SAR image is generated based on the allocated polarimetric observation data sequence. Then, in the moving object detection processing 263, a moving object detection image is generated based on the sorted MTI observation data sequence.

  With the above configuration, the polarimetric SAR device 20 operates as follows.

  FIG. 6 is a flowchart showing the operation of the polarimetric SAR device according to the second embodiment.

  The transmission signal generated by the transmitter 240 is switched between H-polarization transmission and V-polarization transmission for each transmission pulse by the switch 221, and the H-polarization antenna 211 and the V-polarization antenna (Σ / Δ antenna) are passed through the corresponding circulator 281. ) 212 are transmitted alternately (S201).

  The signals reflected from the ground surface are two antennas. An H-polarized Σ signal (HΣ) is output from an H-polarized antenna 211, and a V-polarized Σ signal (VΣ) is output from a V-polarized antenna (Σ / Δ antenna) 212. And a Δ signal (VΔ) of the V polarization and a total of three types of signals.

  Among them, HΔ and VΔ are switched for each transmission pulse by the switch 222 and received by the receiver 231 (S202). Then, VΣ is directly received by the receiver 232 for each transmission pulse (S203).

  At this time, the control unit 250 outputs the PRI trigger in synchronization with the switches 221 and 222, and sets the transmission polarization type output by the switch 221 and the reception polarization type output by the switch 222 to be the same. Control is performed (S204).

  The received signal is digitized by the receiver 231 and the receiver 232 and output as observation data sequence 1 and observation data sequence 2 (S205).

  The observation data sequence 1 and the observation data sequence 2 are input to the recording unit 270 and recorded by the recording unit 270. The recorded observation data sequence 1 and observation data sequence 2 are transferred to the image processing device 260 (S206).

  In the image processing device 260, the input observation data sequence 1 and the observation data sequence 2 are sorted into the polarimetry observation data sequence used for polarimetry observation and the MTI observation data sequence used for mobile object detection (MTI) by the above-described separation processing 261 ( S207).

  A polarimetric SAR image is generated by the polarimetric SAR image processing 262 based on the allocated polarimetry observation data sequence, and a moving object detection image is generated by the moving object detection process 263 based on the allocated MTI observation data sequence (S207).

  Next, observation data in the polarimetric SAR device 20 will be described.

  FIG. 7 is a diagram illustrating combinations of observation data in the polarimetric SAR device according to the second embodiment.

  The upper part of FIG. 7 shows the data contents of the observation data sequence 1 output from the receiver 231 and the observation data sequence 2 output from the receiver 232, based on the switching states of the switches 221 and 222 for each transmission pulse by the PRI trigger. It is shown correspondingly. In this figure, the switch 221 is shown as a switch 1 and the switch 222 is shown as a switch 2.

  7 are the polarimetry observation data sequence (middle stage) and the MTI observation data sequence (lower stage) in which the input observation data sequence 1 and observation data sequence 2 are sorted by the separation processing 261 of the image processing device 260. Respectively.

  The observation data sequence 1 and the observation data sequence 2 shown in the upper part of FIG. 7 are configured as follows.

  First, the switch 1 alternately switches the transmission polarization between H polarization and V polarization at each PRI trigger (each transmission pulse). Since the signal at the time of transmission is transmitted from the entire surface of the antenna, it is a Σ signal in each case.

  The switch 2 alternately switches the reception polarization between H polarization and V polarization at each PRI trigger (each transmission pulse). The switching of the polarization type is controlled to be the same as the transmission polarization type switched by the switch 1. The switch 2 receives the received signal HΣ of the H-polarized antenna 211 and the received signal VΔ of the V-polarized antenna (Σ / Δ antenna) 212, and is switched for each PRI trigger and input to the receiver 231. This is output as observation data sequence 1.

  Further, the received signal VΣ of the V-polarized antenna (Δ / Δ antenna) 212 is directly input to the receiver 232 for each PRI trigger. This is output as the observation data sequence 2.

  Therefore, the following data is obtained as observation data for each PRI trigger.

  In the PRI # 1, the switch 1 and the switch 2 perform HΣ transmission and HΣ reception, respectively. Therefore, HΣ transmission / HΣ reception (HΣ−HΣ) in the observation data sequence 1 and HΣ transmission / VΣ in the observation data sequence 2. Reception (HΣ−VΣ) is obtained.

  In the PRI # 2, the switch 1 and the switch 2 perform VΣ transmission and VΔ reception, respectively. Therefore, VΣ transmission / VΔ reception (VΣ−VΔ) in the observation data sequence 1 and VΣ transmission / VΣ in the observation data sequence 2. Reception (VΣ−VΣ) is obtained.

  Then, the above-described observation data with these two transmission pulses as one set is repeatedly received. That is, HΣ-HΣ and VΣ-VＶ appear alternately in observation data sequence 1, and HΣ-VΣ and VΣ-VΣ appear alternately in observation data sequence 2.

  Next, the observation data sequence 1 and the observation data sequence 2 are sorted into polarimetry observation data and MTI observation data by the separation processing 261 of the image processing device 260. Each observation data is composed as follows.

  First, HΣ-H ト リ of the observation data sequence 1 and HΣ-VΣ and VΣ-VΣ of the observation data sequence 2 are used as the polarimetry observation data in the middle stage of FIG. VΣ−VΔ of the observation data sequence 1 is not used.

  Further, as the MTI observation data in the lower part of FIG. 7, VΣ−VΔ of the observation data sequence 1 and VΣ−VΣ of the observation data sequence 2 are used. HΣ-HΣ of observation data sequence 1 and HΣ-VΣ of observation data sequence 2 are not used.

  Polarimetry observation data HΣ-HΣ, HΣ-VΣ, and VΣ-VΣ are processed by the polarimetry SAR image processing 262 to become a polarimetry SAR image.

  VΣ−VΔ and VΣ−VΣ of the MTI observation data are processed by the mobile object detection processing 263 as V-polarized antenna Δ signal reception data and V-polarized antenna Σ signal reception data, respectively, to become mobile object detection images.

  As described above, in the present embodiment, the V-polarized antenna 212 is a Σ / Δ antenna, and the switch ２２２ switches between the received の signal of the H-polarized antenna 211 and the received Δ signal of the V-polarized antenna for each transmission pulse for observation. It was configured to obtain data string 1. Also, the reception Σ signal of the V-polarized antenna is configured to obtain the observation data sequence 2 as it is for each transmission pulse. In the present embodiment, control is performed so that the polarization type of the transmission signal switched by the switch 221 and the polarization type of the reception signal switched by the switch 222 are the same. As a result, four types of observation data of H デ ー タ -HΣ, VΣ-VΔ, HΣ-VΣ, and VΣ-VΣ can be obtained.

  These observation data are divided into polarimetry observation data (HΣ-HΣ, HΣ-VΣ, VΣ-VΣ) and MTI observation data (VΣ-VΔ, VΣ-VΣ), and a polarimetry SAR image and a moving object detection image are generated, respectively. Is done.

  4 to 7, the V-polarized antenna is described as a Σ / Δ antenna. However, in the present embodiment, the same effect can be obtained even when the H-polarized antenna is a Σ / Δ antenna.

  In that case, VΣ-VΣ and HΣ-HΔ are obtained as the observation data sequence 1, and VΣ-HΣ and HΣ-HΣ are obtained as the observation data sequence 2. Then, VΣ-VΣ, VΣ-HΣ, and HΣ-H 選 are selected as polarimetry observation data, and HΣ-HΣ and HΣ-HΔ are selected, and H-polarized antenna signal received data and H-polarized data are respectively obtained. MTI observation data may be used as antenna Δ signal reception data.

  In the above description, the switch 221 that switches between H-polarization transmission and V-polarization transmission is provided outside the transmitter 240. However, the transmitter 240 includes a polarization changeover switch, and performs switching of transmission polarization before performing high-power amplification, and performs high-power amplification of each transmission polarization after switching. Is also good. In this case, the PRI trigger from the control unit 250 is supplied to the transmitter 240.

  Further, the image processing device 260 configured as a part of the polarimetric SAR device may be configured to be installed on the ground separately from other devices as long as the observation data sequence 1 and the observation data sequence 2 are supplied. good.

  As described above, in the present embodiment, by using the H-polarized antenna or the V-polarized antenna as the Σ / Δ antenna, it is possible to acquire both data necessary for polarimetric SAR observation and data necessary for mobile object detection. . As an additional configuration required for that, it is sufficient to provide a switch for switching between the Δ signal received by the Σ / Δ antenna and the Σ signal received by the other antenna. Since the data required for the acquired polarimetric SAR observation and the data required for the mobile object detection are selected by the separation processing of the image processing apparatus, even when the polarimetric SAR observation and the mobile object detection observation are performed simultaneously, The amount of observation data does not increase. Therefore, as compared with the configuration shown in FIG. 19, the increase in the number of antennas and the number of receivers can be suppressed, and the increase in observation data can be suppressed.

  As described above, in the present embodiment, the polarimetric SAR observation function and the moving object detection function can be simultaneously realized while suppressing the scale of the apparatus and the increase in observation data to be recorded and processed.

(Third embodiment)
Next, a third embodiment of the present invention will be described.

  FIG. 8 is a block diagram showing the configuration of the polarimetric SAR device according to the third embodiment of the present invention.

  The polarimetric SAR device 30 according to the third embodiment has the same configuration as the polarimetric SAR device 20 according to the second embodiment shown in FIG. 4 except that the H polarization antenna is also a Σ / Δ antenna. That is, both the H polarization antenna 311 and the V polarization antenna 312 are configured as Σ / Δ antennas.

  In the present embodiment, there are four types of reception signals: an H polarization reception signal (HΣ), an H polarization reception Δ signal (HΔ), a V polarization reception signal (V 波), and a V polarization reception Δ signal (VΔ). Is obtained.

  Other configurations are the same as those of the polarimetric SAR device 20 of the second embodiment shown in FIG. However, the switch 222 is configured to switch the reception Σ signal (VΣ) of the V polarization antenna 312 and the reception Δ signal (HΔ) of the H polarization antenna 311 and supply observation data to the receiver 232. . The reception Σ signal (HΣ) of the H polarization antenna 311 is configured to be supplied to the receiver 231.

  In the present embodiment, the configuration is such that the V polarization reception Δ signal (VΔ) is not used.

  With the above configuration, the combination of observation data shown in FIG. 9 can be obtained.

  The observation data sequence 1 and the observation data sequence 2 shown in the upper part of FIG. 9 are configured as follows.

  The switches 1 and 2 in FIG. 9 correspond to the switches 221 and 222 shown in FIG. 8, respectively.

  First, the switch 1 alternately switches the transmission polarization between H polarization and V polarization at each PRI trigger (each transmission pulse). Since the signal at the time of transmission is transmitted from the entire surface of the antenna, it is a Σ signal in each case.

  The switch 2 alternately switches the reception polarization between H polarization and V polarization at each PRI trigger (each transmission pulse). The switching of the polarization type is controlled to be the same as the transmission polarization type switched by the switch 1.

  The switch 2 receives the received Δ signal (HΔ) of the H-polarized antenna 311 and the received Σ signal (V の) of the V-polarized antenna 312, and is switched for each PRI trigger and input to the receiver 232. This is output as the observation data sequence 2.

  Further, the reception signal (H) of the H polarization antenna 311 is directly input to the receiver 231 at each PRI trigger. This is output as observation data sequence 1.

  Therefore, the following data is obtained as observation data for each PRI trigger.

  In PRI # 1, the switch 1 and the switch 2 perform HΣ transmission and HΔ reception, respectively. Therefore, H 観 測 transmission / HΣ reception (HΣ−HΣ) is observed in the observation data sequence 1, and HΣ transmission / HΔ is observed in the observation data sequence 2. The reception (HΣ−HΔ) is obtained.

  In the PRI # 2, the switch 1 and the switch 2 perform VΣ transmission and VΣ reception, respectively. Therefore, VΣ transmission / H が reception (VΣ−HΣ) in the observation data sequence 1 and VΣ transmission / VΣ in the observation data sequence 2. Reception (VΣ−VΣ) is obtained.

  Then, the above-described observation data with these two transmission pulses as one set is repeatedly received. That is, HΣ-HΣ and VΣ-HΣ appear alternately in the observation data sequence 1, and HΣ-HΔ and VΣ-VΣ appear alternately in the observation data sequence 2.

  Next, the observation data sequence 1 and the observation data sequence 2 are sorted into polarimetry observation data and MTI observation data by the separation processing 261 of the image processing device 260. Each observation data is composed as follows.

  First, HΣ-HΣ and VΣ-H 段 of the observation data sequence 1 and VΣ-VΣ of the observation data sequence 2 are used as the polarimetry observation data in the middle stage of FIG. Then, HΣ−HΔ of the observation data sequence 2 is not used.

  As the MTI observation data in the lower part of FIG. 9, H９−HΣ of the observation data sequence 1 and HΣ−HΔ of the observation data sequence 2 are used. V {-H} of observation data sequence 1 and V {-V} of observation data sequence 2 are not used.

  Polarimetry observation data HΣ-HΣ, VΣ-HΣ, and VΣ-VΣ are processed by polarimetry SAR image processing 262 to become polarimetry SAR images.

  HΣ-HΣ and HΣ-HΔ of the MTI observation data are processed by the mobile object detection processing 263 as H-polarized antenna Σ signal reception data and H-polarization antenna Δ signal reception data, respectively, to become mobile object detection images.

  Note that, in the present embodiment as well, as in the third embodiment, the transmitter 240 may be configured to include a polarization switch. Further, the image processing device 260 may be configured to be separated from other devices and installed on the ground.

  As described above, also in the present embodiment, the polarimetric SAR observation function and the moving object detection function can be realized at the same time while suppressing the scale of the apparatus and the increase in observation data to be recorded / processed.

(Fourth embodiment)
Next, a fourth embodiment of the present invention will be described.

  FIG. 10 is a block diagram showing the configuration of the polarimetric SAR device according to the fourth embodiment of the present invention.

  The polarimetric SAR device 40 of the fourth embodiment has a configuration in which, in the polarimetric SAR device 30 of the third embodiment shown in FIG. I have. The polarimetric SAR device 40 according to the fourth embodiment further includes a switch 223 as the switch 2-2. The switch 223 is configured to switch the reception Δ signal (VΔ) of the V polarization antenna 312 and the reception Σ signal (HΣ) of the H polarization antenna 311 and supply observation data to the receiver 231. The switch 222 will be described as a switch 2-1.

  In this embodiment, the switch 222 or the switch 223 is set to be fixed, and the reception Δ signal (HΔ) output from the H polarization antenna 311 or the reception Δ signal (VΔ) output from the V polarization antenna 312 is selected. It can be used.

  A combination of observation data obtained in the fourth embodiment will be described with reference to FIG.

  The upper part of FIG. 11 shows observation data when the switch 222 (switch 2-1) is fixed at VΣ. In this case, the configuration is such that HΔ output from the H polarization antenna 311 is not used. Accordingly, the configuration of the polarimetric SAR device 40 in this case is equivalent to the configuration of the polarimetric SAR device 20 of the second embodiment shown in FIG. That is, the same observation data as that shown in FIG. 7 is obtained.

  The lower part of FIG. 11 shows observation data when the switch 223 (switch 2-2) is fixed at HΣ. In this case, the configuration is such that VΔ output from the V-polarized antenna 312 is not used. Therefore, the configuration of the polarimetric SAR device 40 in this case is equivalent to the configuration of the polarimetric SAR device 30 of the third embodiment shown in FIG. That is, the same observation data as that shown in FIG. 9 is obtained.

  As described above, the polarimetric SAR device 40 of the fourth embodiment can obtain observation data in which the polarization type is switched according to the observation target.

  Note that, in the present embodiment as well, as in the third embodiment, the transmitter 240 may be configured to include a polarization switch. Further, the image processing device 260 may be configured to be separated from other devices and installed on the ground.

  As described above, in this embodiment, both the H polarization antenna and the V polarization antenna are Σ / Δ antennas, so that both data required for polarimetric SAR observation and data required for mobile object detection can be obtained. Can be. In addition, the polarization type can be switched flexibly according to the characteristics of the observation target. As an additional configuration required for that, it is sufficient to provide two sets of switches for switching between a Δ signal received by one Σ / Δ antenna and a Σ signal received by the other Σ / Δ antenna. Since the data required for the acquired polarimetric SAR observation and the data required for the mobile object detection are selected by the separation processing of the image processing apparatus, even when the polarimetric SAR observation and the mobile object detection observation are performed simultaneously, The amount of observation data does not increase. Therefore, as compared with the configuration shown in FIG. 19, the increase in the number of antennas and the number of receivers can be suppressed, and the increase in observation data can be suppressed.

  As described above, also in the present embodiment, the polarimetric SAR observation function and the moving object detection function can be realized at the same time while suppressing the scale of the apparatus and the increase in observation data to be recorded / processed.

(Fifth embodiment)
Next, a fifth embodiment of the present invention will be described.

  FIG. 12 is a block diagram showing a configuration of the polarimetric SAR device according to the fifth embodiment of the present invention.

  The polarimetric SAR device 50 according to the fifth embodiment has a configuration in which the H-polarized antenna and the V-polarized antenna to be used are H / V-polarized Σ / Δ antennas 410. Other configurations are the same as those of the polarimetric SAR device 20 of the second embodiment shown in FIG.

  The H / V polarization shared Σ / Δ antenna 410 transmits H or V polarization during transmission, and receives は and Δ signals of H and V polarization during reception. That is, during transmission, the H-polarized or V-polarized Σ signal switched by the switch 221 is transmitted. Then, four types of reception signals, ie, H-polarization reception Σ signal (HΣ), H-polarization reception Δ signal (HΔ), V-polarization reception Σ signal (VΣ), and V-polarization reception Δ signal (VΔ), are used. can get.

  In the present embodiment, the configuration is such that HΔ is terminated and not used. Then, similarly to the configuration of the polarimetric SAR device 20 of the second embodiment shown in FIG. 4, the received HΣ and VΔ are switched by the switch 222 to obtain the observation data sequence 1.

  With the above configuration, the same data as the combination of the observation data shown in FIG. 7 can be obtained.

  In FIG. 12, the received HΔ is terminated and not used, but the received VΔ may not be used. In this case, as in the polarimetric SAR device 30 according to the third embodiment of FIG. 8, the received data Σ and the received HΔ may be switched by the switch 222 to obtain the observation data sequence 2.

  Note that, in the present embodiment as well, as in the third embodiment, the transmitter 240 may be configured to include a polarization switch. Further, the image processing device 260 may be configured to be separated from other devices and installed on the ground.

  As described above, in the present embodiment, the H polarization antenna and the V polarization antenna are used as one H / V polarization shared Σ / Δ antenna, so that the data required for polarimetric SAR observation and the data required for mobile object detection are obtained. You can get both. As an additional configuration required for that, it is sufficient to provide a switch for switching between a Δ signal received with one polarization and a Σ signal received with the other polarization. Since the data required for the acquired polarimetric SAR observation and the data required for the mobile object detection are selected by the separation processing of the image processing apparatus, even when the polarimetric SAR observation and the mobile object detection observation are performed simultaneously, The amount of observation data does not increase. Therefore, as compared with the configuration shown in FIG. 19, the increase in the number of antennas and the number of receivers can be suppressed, and the increase in observation data can be suppressed.

  As described above, also in the present embodiment, the polarimetric SAR observation function and the moving object detection function can be realized at the same time while suppressing the scale of the apparatus and the increase in observation data to be recorded / processed.

(Sixth embodiment)
The configuration of the polarimetric SAR device of the sixth embodiment is the same as the configuration of the polarimetric SAR device 20 of the second embodiment shown in FIG.

  The present embodiment is different in that the control unit 250 performs the switching operation of the switches 221 and 222 at a speed 1.5 times faster than the switching operation in the second embodiment. The transmission polarization type of the switch 221 is H polarization, V polarization, and V polarization, and the reception polarization type of the switch 222 that operates in synchronization is H polarization, H polarization, and V polarization. That is, three transmission pulses are set as one set, and the first and third transmission pulses are controlled so that the transmission polarization type and the reception polarization type are the same, and the second transmission pulse is reversed. .

  FIG. 13 shows a combination of observation data in the polarimetric SAR device according to the sixth embodiment configured as described above.

  In the polarimetry SAR device of the sixth embodiment, three transmission pulses are set as one set, and HΣ-HΣ, VΣ-HΣ, and VΣ-VΔ in the observation data sequence 1, and HΣ-VΣ and VΣ-VΣ in the observation data sequence 2. , V {−V} are repeatedly received (see the upper part of FIG. 13).

  In the present embodiment, as shown in the middle part of FIG. 13, the polarimetry observation data includes four types of observation data, that is, HΣ-HΣ and VΣ-HΣ from the observation data sequence 1 and HΣ-VΣ and VΣ-VΣ from the observation data sequence 2. Can be obtained.

  Note that, as shown in the lower part of FIG. 13, VΣ−VΔ and VΣ−VΣ are obtained from the MTI observation data as in the case of FIG.

  In the present embodiment, the amount of observation data is 1.5 times that in the second embodiment, but more accurate data analysis is possible.

  As described above, in the present embodiment, as in the second embodiment, the H polarization antenna or the V polarization antenna is a Σ / Δ antenna, so that the data required for polarimetric SAR observation and the data required for mobile object detection are obtained. Both data can be obtained. As an additional configuration required for that, it is sufficient to provide a switch for switching between the Δ signal received by the Σ / Δ antenna and the Σ signal received by the other antenna. In addition, the acquired data necessary for the polarimetric SAR observation and the data necessary for the moving object detection are sorted out by the separation processing of the image processing apparatus. Accordingly, the amount of observation data is 1.5 times as large as that of the second embodiment. However, compared to a configuration in which the polarimetric SAR observation data and the moving object detection observation data are individually acquired, the increase in the total amount of observation data is reduced. Can be suppressed. Therefore, as compared with the configuration shown in FIG. 19, the increase in the number of antennas and the number of receivers can be suppressed, and the increase in observation data can be suppressed.

  Also in the present embodiment, the polarimetric SAR observation function and the moving object detection function can be realized at the same time while suppressing the scale of the apparatus and the increase in observation data to be recorded / processed.

(Seventh embodiment)
Each of the embodiments described above is a configuration for simultaneously realizing the polarimetric SAR observation function and the moving object detection function. However, the polarimetric SAR observation or the moving object detection can be individually performed with the same configuration.

  A description will be given with reference to the configurations of the first embodiment of FIG. 2 and the second embodiment of FIG.

  For example, when only polarimetric SAR observation is performed without detecting a moving object, the second switch 122 in FIG. 2 and the switch 222 in FIG. 4 are not switched, and the reception Δ signal of the Σ / Δ antenna is not passed. What is necessary is to fix only to the reception signal of the other antenna.

  When only the mobile object detection is performed without performing polarimetric SAR observation, only the received Δ signal of the Σ / Δ antenna is passed without switching the second switch 122 in FIG. 2 or the switch 222 in FIG. Control may be performed as follows. In this case, the polarization type transmitted by the Σ / Δ antenna may be fixed without switching the first switch 121 in FIG. 2 or the switch 221 in FIG.

  Such switching control of each switch may be executed by the control unit 150 of FIG. 2 or the control unit 250 of FIG. 4 based on an external control instruction (not shown).

  FIG. 14 is a diagram showing combinations of observation data in the polarimetric SAR device according to the seventh embodiment. The observation data shown is for the case where the V-polarized antenna is a Σ / Δ antenna. Note that the switch 1 in FIG. 14 corresponds to the first switch 121 in FIG. 2 and the switch 221 in FIG. 4, and the switch 2 corresponds to the second switch 122 in FIG. 2 and the switch 222 in FIG.

  The upper part of FIG. 14 shows the switching / fixed state of the switch when the polarimetric SAR observation is performed independently and the contents of the observation data acquired correspondingly. That is, the switch 2 is fixed at HΣ reception. As a result, four types of observation data of HΣ-HΣ, HΣ-VΣ, VΣ-HΣ, and VΣ-VΣ according to the switching of the switch 1 can be used for polarimetric SAR observation.

  The middle part of FIG. 14 shows the switching / fixed state of the switch when the moving object detection is executed alone and the contents of the observation data acquired correspondingly. That is, the switch 2 is fixed to VΔ reception.

  The lower part of FIG. 14 shows the case where the mobile object detection is executed independently, and shows the contents of observation data that can be acquired when the switch 1 is further fixed to the V polarization transmission from the state of the middle part of FIG. In this case, VΣ−VΔ and VΣ−VΣ of the MTI observation data can be obtained for each transmission pulse.

  Thus, for example, when the calculation capability of the image processing apparatus is limited, the observation operation can be switched and performed by the same apparatus. For example, it is possible to perform an observation operation that switches between polarimetric SAR observation performed at high resolution, mobile object detection observation performed at high resolution, and mobile object detection and polarimetric SAR observation performed at low resolution.

  In addition, it is possible to cope with a case where not only a pseudo color image is generated by polarimetry SAR observation but also an advanced analysis that requires observation data of a combination of four types of polarization is required.

  As described above, the polarimetric SAR device according to the embodiment of the present invention uses at least one of the antennas as the Σ / Δ antenna, and includes the switch that switches between the 信号 signal received by the Σ / Δ antenna and the Σ signal received by the other antenna. A degree of configuration may be added. Therefore, it can be said that there is almost no increase in the device scale. Further, even when the polarimetric SAR observation and the mobile object detection observation are performed simultaneously, the total amount of observation data does not increase. Therefore, even when the observation data is transmitted from an aircraft or satellite to the ground, the polarimetric SAR observation and the mobile object detection observation can be performed simultaneously without increasing the time required for data transmission.

  As described above, in the present embodiment, the polarimetric SAR observation function and the moving object detection function can be simultaneously realized while suppressing the scale of the apparatus and the increase in observation data to be recorded and processed.

In addition, some or all of the above-described embodiments may be described as in the following supplementary notes, but are not limited thereto.
(Supplementary Note 1) An H-polarized antenna that is an antenna of a synthetic aperture radar (SAR), at least one of which is a Σ / Δ antenna in which two divided antenna surfaces are arranged in front and behind in the traveling direction. An H-polarized antenna for transmitting and receiving radio waves and a V-polarized antenna for transmitting and receiving V-polarized waves;
A first switch for switching a transmission signal between H polarization transmission and V polarization transmission for each transmission pulse;
The sum of the difference (Δ) signal received by the first polarization antenna, which is the Σ / Δ antenna, which is one of the H polarization antenna and the V polarization antenna, and the other second polarization antenna receives (Ii) a second switch for switching a signal for each transmission pulse;
Control means for outputting the transmission pulse in synchronization with the first switch and the second switch;
A first receiver that receives a Δ signal received by the first polarization antenna and a Σ signal received by the second polarization antenna corresponding to the transmission pulse, and outputs a first observation data sequence When,
A second receiver that receives the Σ signal received by the first polarization antenna corresponding to the transmission pulse, and outputs a second observation data sequence;
The first data used for polarimetry observation and the second data used for mobile object detection are selected from the first observation data sequence and the second observation data sequence, and a polarimetry SAR image is generated from the first data. Image processing means for generating a moving object detection image from the second data;
A polarimetric SAR device comprising:
(Supplementary Note 2) When the first polarization antenna is the V polarization antenna, and the second polarization antenna is the H polarization antenna,
The control unit sets the transmission polarization type output by the first switch and the reception polarization type output by the second switch to be the same for each of the transmission pulses as two sets of the transmission pulses. , H polarizationΣsignal transmission / H polarizationΣsignal reception (HΣ−HΣ), V polarizationΣsignal transmission / V polarization Δ signal reception (VΣ−VΔ) as the first observation data, and H polarization {Signal transmission / V polarization} signal reception (H （−VΣ), V polarization {signal transmission / V polarizationＶsignal reception (VΣ−V}) are controlled so as to be obtained as the second observation data,
The image processing means selects the observation data of HΣ-HΣ, HΣ-VΣ, and VΣ-VΣ as the first data to generate a polarimetric SAR image, and converts the observation data of VΣ-VΔ, VΣ-VΣ into the first data. 2. The polarimetry SAR device according to claim 1, wherein a moving object detection image is generated by selecting as the second data.
(Supplementary Note 3) The second polarization antenna is also the Σ / Δ antenna, and the second switch receives the Δ signal received by the second polarization antenna and the reception of the Δ signal received by the first polarization antenna. The first signal is switched for each transmission pulse, and the first receiver receives the Σ signal received by the second polarization antenna in accordance with the transmission pulse and converts the first observation data sequence. And the second receiver receives a Σ signal received by the first polarization antenna and a Δ signal received by the second polarization antenna corresponding to the transmission pulse, and 2. The polarimetric SAR device according to claim 1, wherein the observation data sequence is output.
(Supplementary Note 4) When the first polarization antenna is the V polarization antenna, and the second polarization antenna is the H polarization antenna,
The control unit sets the transmission polarization type output by the first switch and the reception polarization type output by the second switch to be the same for each of the transmission pulses as two sets of the transmission pulses. , H-polarized signal transmission / H-polarized signal reception (H-H), V-polarized signal transmission / H-polarized signal reception (V-H) as the first observation data, Σsignal transmission / H polarization Δ signal reception (HΣ−HΔ), V polarizationΣsignal transmission / V polarizationΣsignal reception (VΣ−VΣ) are controlled so as to be obtained as the second observation data,
The image processing means selects polarimetric SAR images by selecting observation data of HΣ-HΣ, VΣ-HΣ, and VΣ-VΣ as the first data, and generates observation data of HΣ-HΣ, HΔ-HΣ 4. The polarimetry SAR device according to claim 3, wherein a moving object detection image is generated by selecting the data as the second data.
(Supplementary Note 5) A third switch that switches a Δ signal received by the first polarization antenna and a Σ signal received by the second polarization antenna for each transmission pulse,
The control means performs control to fix switching of any one of the second switch and the third switch to a Σ signal,
When the switching of the second switch is fixed to the Σ signal, the first receiver outputs the Δ signal received by the first polarization antenna and the Σ signal received by the second polarization antenna. The first receiver receives the transmission pulse and outputs the first observation data sequence, and the second receiver receives the Σ signal received by the first polarization antenna in response to the transmission pulse. And outputs the second observation data sequence,
When the switching of the third switch is fixed to the Σ signal, the first receiver receives the Σ signal received by the second polarization antenna in response to the transmission pulse, and receives the first signal. And the second receiver receives a Σ signal received by the first polarization antenna and a Δ signal received by the second polarization antenna corresponding to the transmission pulse. 4. The polarimetry SAR device according to claim 3, wherein the second observation data sequence is output as a result.
(Supplementary Note 6) The H-polarized antenna and the V-polarized antenna are configured as H / V-polarized Σ / Δ antennas, and the H-polarized and V-polarized antennas received by the H / V-polarized Σ / Δ antenna are received. Of the Σ and Δ signals of each of the waves, using the Σ and Δ signals received on one of the first polarizations and the Σ signal received on the other second polarization,
The second switch switches a Δ signal received with the first polarization and a Σ signal received with the second polarization for each transmission pulse,
The first receiver receives a Δ signal received with the first polarization and a Σ signal received with the second polarization corresponding to the transmission pulse and outputs a first observation data sequence. And
The polarimetry SAR according to claim 1, wherein the second receiver receives the Σ signal received with the second polarization in accordance with the transmission pulse and outputs a second observation data sequence. apparatus.
(Supplementary Note 7) The control unit sets the three transmission pulses as one set, and sets the transmission polarization type output by the first switch in the case of the first and third transmission pulses in the set. And the type of reception polarization output by the second switch is the same, and in the case of the second transmission pulse, the type of transmission polarization output by the first switch and the type of reception polarization output by the second switch Perform control to reverse the type,
The image processing means according to claim 1, wherein the observation data of HΣ-HΣ, VΣ-HΣ, HΣ-VΣ, and VΣ-VΣ are selected as the first data to generate a polarimetric SAR image. Polarimetric SAR device.
(Supplementary Note 8) The control unit fixes the output of the second switch to one of a Δ signal received by the first polarization antenna and a ま た は signal received by the second polarization antenna. Do
When the output of the second switch is fixed to the Σ signal received by the second polarization antenna, the image processing means performs polarimetry from the first observation data sequence and the second observation data sequence. Generates a SAR image, and moves from the first observation data sequence and the second observation data sequence when the output of the second switch is fixed to the Δ signal received by the first polarization antenna. The polarimetry SAR device according to any one of supplementary notes 1, 3, and 6, wherein the polarimetry SAR apparatus generates a body detection image.
(Supplementary Note 9) When the output of the second switch is fixed to the Δ signal received by the first polarization antenna, the control unit controls the first switch to perform H polarization transmission or V polarization transmission. 9. The polarimetric SAR device according to claim 8, wherein the polarimetric SAR device is fixed to one of the two.
(Supplementary Note 10) An H-polarized antenna which is an antenna of a synthetic aperture radar (SAR), at least one of which is a Σ / Δ antenna in which two divided antenna surfaces are arranged in front and behind in the traveling direction. A transmission signal is switched to H polarization transmission and V polarization transmission for each transmission pulse by a first switch and supplied to an H polarization antenna performing wave transmission and reception and a V polarization antenna performing V polarization transmission and reception,
The sum of the difference (Δ) signal received by the first polarization antenna, which is the Σ / Δ antenna, which is one of the H polarization antenna and the V polarization antenna, and the other second polarization antenna receives (Σ) The signal is switched for each transmission pulse by the second switch,
Outputting the transmission pulse in synchronization with the first switch and the second switch;
Receiving a Δ signal received by the first polarization antenna and a Σ signal received by the second polarization antenna corresponding to the transmission pulse and outputting a first observation data sequence;
Receiving the ア ン テ ナ signal received by the first polarization antenna corresponding to the transmission pulse and outputting a second observation data sequence;
First data used for polarimetry observation and second data used for moving object detection are selected from the first observation data sequence and the second observation data sequence,
An observation method, comprising: generating a polarimetric SAR image from the first data; and generating a moving object detection image from the second data.
(Supplementary Note 11) When the first polarization antenna is the V polarization antenna, and the second polarization antenna is the H polarization antenna,
The transmission polarization type output from the first switch and the reception polarization type output from the second switch are set to be the same for each transmission pulse by setting the two transmission pulses as one set. Signal transmission / H polarization / signal reception (HΣ−HΣ), V polarization / signal transmission / V polarization Δ signal reception (VΣ−VΔ) as the first observation data, and H polarization / signal transmission / V Control so that polarization {signal reception (H} -V}, V polarization {signal transmission / V polarization} signal reception (V {−V}) can be obtained as the second observation data,
The observation data of HΣ-HΣ, HΣ-VΣ, and VΣ-VΣ are selected as the first data to generate a polarimetric SAR image, and the observation data of VΣ-VΔ, VΣ-VΣ are selected as the second data. 11. The observation method according to Supplementary Note 10, wherein a moving object detection image is generated by using the method.
(Supplementary Note 12) The second polarization antenna is also the Σ / Δ antenna,
The Δ signal received by the second polarization antenna and the Σ signal received by the first polarization antenna are switched by the second switch for each transmission pulse,
Receiving the Σ signal received by the second polarization antenna corresponding to the transmission pulse and outputting the first observation data sequence;
Receiving the Σ signal received by the first polarization antenna and the Δ signal received by the second polarization antenna corresponding to the transmission pulse, and outputting the second observation data sequence. 13. The observation method according to supplementary note 10, wherein
(Supplementary Note 13) When the first polarization antenna is the V polarization antenna, and the second polarization antenna is the H polarization antenna,
The transmission polarization type output from the first switch and the reception polarization type output from the second switch are set to be the same for each transmission pulse by setting the two transmission pulses as one set. Signal transmission / H polarization / signal reception (H-H), V polarization / signal transmission / H polarization / signal reception (V-H) as the first observation data, and H polarization / signal transmission / H Control so that polarization Δ signal reception (HΣ−HΔ), V polarization {signal transmission / V polarizationΣ signal reception (VΣ−V}) can be obtained as the second observation data,
The observation data of HΣ-HΣ, VΣ-HΣ, and VΣ-VΣ are selected as the first data to generate a polarimetric SAR image, and the observation data of HΣ-HΔ, HΣ-HΣ are selected as the second data. 13. The observation method according to supplementary note 12, wherein a moving object detection image is generated by using the method.
(Supplementary Note 14) A Δ switch received by the first polarization antenna and a Σ signal received by the second polarization antenna are switched by a third switch for each transmission pulse,
Performing control to fix the switching of any one of the second switch and the third switch to the Σ signal;
When the switching of the second switch is fixed to the Σ signal, the Δ signal received by the first polarization antenna and the Σ signal received by the second polarization antenna are received corresponding to the transmission pulse. And outputs the first observation data sequence, receives the Σ signal received by the first polarization antenna corresponding to the transmission pulse, and outputs the second observation data sequence,
When the switching of the third switch is fixed to the Σ signal, the 偏 signal received by the second polarization antenna is received corresponding to the transmission pulse, and the first observation data sequence is output. Receiving the Σ signal received by the first polarization antenna and the Δ signal received by the second polarization antenna corresponding to the transmission pulse, and outputting the second observation data sequence. 13. The observation method according to supplementary note 12, wherein
(Supplementary Note 15) The H-polarized antenna and the V-polarized antenna are configured by H / V-polarized Σ / Δ antennas, and the H-polarized and V-polarized waves received by the H / V-polarized Σ / Δ antenna are received. Of the Σ and Δ signals of each of the waves, using the Σ and Δ signals received on one of the first polarizations and the Σ signal received on the other second polarization,
Switching the Δ signal received with the first polarization and the Σ signal received with the second polarization with the second switch for each transmission pulse;
A Δ signal received with the first polarization and a Σ signal received with the second polarization are received corresponding to the transmission pulse and a first observation data sequence is output,
11. The observation method according to claim 10, wherein a Σ signal received with the second polarization is received in response to the transmission pulse, and a second observation data sequence is output.
(Supplementary Note 16) The three transmission pulses are regarded as one set, and in the case of the first and third transmission pulses of the set, the transmission polarization type output by the first switch and the second The type of reception polarization output by the switch is the same, and in the case of the second transmission pulse, the type of transmission polarization output by the first switch and the type of reception polarization output by the second switch are reversed. Control,
The observation method according to claim 10, wherein the observation data of HΣ-HΣ, VΣ-HΣ, HΣ-VΣ, and VΣ-VΣ are selected as the first data to generate a polarimetric SAR image.
(Supplementary Note 17) Control is performed to fix the output of the second switch to either a Δ signal received by the first polarization antenna or a Σ signal received by the second polarization antenna,
If the output of the second switch is fixed to the Σ signal received by the second polarization antenna, generate a polarimetric SAR image from the first observation data sequence and the second observation data sequence,
When the output of the second switch is fixed to the Δ signal received by the first polarization antenna, a moving object detection image is generated from the first observation data sequence and the second observation data sequence. The observation method according to any one of Supplementary Notes 10, 12, and 15, wherein:
(Supplementary Note 18) When the output of the second switch is fixed to the Δ signal received by the first polarization antenna, the first switch is fixed to one of the H polarization transmission and the V polarization transmission. 18. The observation method according to supplementary note 17, wherein

10, 20, 30, 40, 50 Polarimetric SAR device 111, 211, 311 H-polarized antenna 112, 212, 312 V-polarized antenna 121 First switch 122 Second switch 131 First receiver 132 Second Receiver 140 Control unit 150 Image processing unit 221, 222, 223 Switch 231, 232 Receiver 240 Transmitter 250 Control unit 260 Image processing device 261 Separation processing 262 Polarimetric SAR image processing 263 Moving object detection processing 270 Recording unit 281 Circulator 410H / V polarization shared Σ / Δ antenna 500, 501, 502 Polarimetric SAR device 511 H polarization antenna 512 V polarization antenna 513 MTI antenna (F)
514 MTI antenna (A)
521, 522, 523 Circulator 530 Switch 540, 541 Transmitter 551, 552, 553, 554 Receiver 560, 561 Controller 570, 571 Recorder 580, 581 Image processing device

Claims (10)

An antenna of a synthetic aperture radar (SAR), at least one of which is a Σ / Δ antenna in which two divided antenna surfaces are arranged before and after in the traveling direction, performs H-polarized wave transmission / reception. A V-polarized antenna for transmitting and receiving a V-polarized wave to and from an H-polarized antenna,
A first switch for switching a transmission signal between H polarization transmission and V polarization transmission for each transmission pulse;
The sum of the difference (Δ) signal received by the first polarization antenna, which is the Σ / Δ antenna, which is one of the H polarization antenna and the V polarization antenna, and the other second polarization antenna receives (Ii) a second switch for switching a signal for each transmission pulse;
Control means for outputting the transmission pulse in synchronization with the first switch and the second switch;
A first receiver that receives a Δ signal received by the first polarization antenna and a Σ signal received by the second polarization antenna corresponding to the transmission pulse, and outputs a first observation data sequence When,
A second receiver that receives the Σ signal received by the first polarization antenna corresponding to the transmission pulse, and outputs a second observation data sequence;
The first data used for polarimetry observation and the second data used for mobile object detection are selected from the first observation data sequence and the second observation data sequence, and a polarimetry SAR image is generated from the first data. Image processing means for generating a moving object detection image from the second data;
A polarimetric SAR device comprising: When the first polarization antenna is the V polarization antenna and the second polarization antenna is the H polarization antenna,
The control unit sets the transmission polarization type output by the first switch and the reception polarization type output by the second switch to be the same for each of the transmission pulses as two sets of the transmission pulses. , H polarizationΣsignal transmission / H polarizationΣsignal reception (HΣ−HΣ), V polarizationΣsignal transmission / V polarization Δ signal reception (VΣ−VΔ) as the first observation data, and H polarization {Signal transmission / V polarization} signal reception (H （−VΣ), V polarization {signal transmission / V polarizationＶsignal reception (VΣ−V}) are controlled so as to be obtained as the second observation data,
The image processing means selects the observation data of HΣ-HΣ, HΣ-VΣ, and VΣ-VΣ as the first data to generate a polarimetric SAR image, and converts the observation data of VΣ-VΔ, VΣ-VΣ into the first data. 2. The polarimetry SAR device according to claim 1, wherein a moving object detection image is generated by selecting as the second data. The second polarization antenna is also the Σ / Δ antenna, and the second switch converts a Δ signal received by the second polarization antenna and a Σ signal received by the first polarization antenna. Switching for each transmission pulse, the first receiver receives the Σ signal received by the second polarization antenna corresponding to the transmission pulse and outputs the first observation data sequence, The second receiver receives the Σ signal received by the first polarization antenna and the Δ signal received by the second polarization antenna corresponding to the transmission pulse, and receives the second observation data sequence. 2. The polarimetric SAR device according to claim 1, wherein the polarimetric SAR device outputs When the first polarization antenna is the V polarization antenna and the second polarization antenna is the H polarization antenna,
The control unit sets the transmission polarization type output by the first switch and the reception polarization type output by the second switch to be the same for each of the transmission pulses as two sets of the transmission pulses. , H-polarized signal transmission / H-polarized signal reception (H-H), V-polarized signal transmission / H-polarized signal reception (V-H) as the first observation data, Σsignal transmission / H polarization Δ signal reception (HΣ−HΔ), V polarizationΣsignal transmission / V polarizationΣsignal reception (VΣ−VΣ) are controlled so as to be obtained as the second observation data,
The image processing means selects polarimetric SAR images by selecting observation data of HΣ-HΣ, VΣ-HΣ, and VΣ-VΣ as the first data, and generates observation data of HΣ-HΣ, HΔ-HΣ 4. The polarimetry SAR device according to claim 3, wherein the mobile object detection image is generated by selecting as the second data. A third switch that switches a Δ signal received by the first polarization antenna and a Σ signal received by the second polarization antenna for each transmission pulse;
The control means performs control to fix switching of any one of the second switch and the third switch to a Σ signal,
When the switching of the second switch is fixed to the Σ signal, the first receiver outputs the Δ signal received by the first polarization antenna and the Σ signal received by the second polarization antenna. The first receiver receives the transmission pulse and outputs the first observation data sequence, and the second receiver receives the Σ signal received by the first polarization antenna in response to the transmission pulse. And outputs the second observation data sequence,
When the switching of the third switch is fixed to the Σ signal, the first receiver receives the Σ signal received by the second polarization antenna in response to the transmission pulse, and receives the first signal. And the second receiver receives a Σ signal received by the first polarization antenna and a Δ signal received by the second polarization antenna corresponding to the transmission pulse. 4. The polarimetry SAR device according to claim 3, wherein the second observation data sequence is output as a result. The H-polarized antenna and the V-polarized antenna are configured as H / V-polarized Σ / Δ antennas. Of the Σ signal and the 信号 signal, using the Σ signal and the Σ signal received on one of the first polarizations and the Σ signal received on the other second polarization,
The second switch switches a Δ signal received with the first polarization and a Σ signal received with the second polarization for each transmission pulse,
The first receiver receives a Δ signal received with the first polarization and a Σ signal received with the second polarization corresponding to the transmission pulse and outputs a first observation data sequence. And
The polarimetry according to claim 1 , wherein the second receiver receives the Σ signal received with the first polarization in response to the transmission pulse and outputs a second observation data sequence. SAR device. The control means sets the three transmission pulses as one set, and in the case of the first and third transmission pulses of the one set, the transmission polarization type output by the first switch and the second transmission pulse. In the case of the second transmission pulse, the transmission polarization type output by the first switch and the reception polarization type output by the second switch are reversed. Control
2. The polarimetry SAR image according to claim 1, wherein the image processing unit selects observation data of HΣ-HΣ, VΣ-HΣ, HΣ-VΣ, and VΣ-VΣ as the first data to generate a polarimetric SAR image. 3. Polarimetric SAR device. The control means performs control to fix the output of the second switch to either a Δ signal received by the first polarization antenna or a Σ signal received by the second polarization antenna,
When the output of the second switch is fixed to the Σ signal received by the second polarization antenna, the image processing means performs polarimetry from the first observation data sequence and the second observation data sequence. Generates a SAR image, and moves from the first observation data sequence and the second observation data sequence when the output of the second switch is fixed to the Δ signal received by the first polarization antenna. polarimetric SAR apparatus of any crab of claims 1,3,6, characterized in that to produce a body detection image.

The control means, when fixing the output of the second switch to a Δ signal received by the first polarization antenna, fixes the first switch to either H polarization transmission or V polarization transmission. The polarimetric SAR device according to claim 8, wherein An antenna of a synthetic aperture radar (SAR), at least one of which is a Σ / Δ antenna in which two divided antenna surfaces are arranged before and after in the traveling direction, performs H-polarized wave transmission / reception. A transmission signal is switched to H polarization transmission and V polarization transmission for each transmission pulse by a first switch and supplied to a V polarization antenna that performs V polarization transmission and reception with the H polarization antenna,
The sum of the difference (Δ) signal received by the first polarization antenna, which is the Σ / Δ antenna, which is one of the H polarization antenna and the V polarization antenna, and the other second polarization antenna receives (Σ) The signal is switched for each transmission pulse by the second switch,
Outputting the transmission pulse in synchronization with the first switch and the second switch;
Receiving a Δ signal received by the first polarization antenna and a Σ signal received by the second polarization antenna corresponding to the transmission pulse and outputting a first observation data sequence;
Receiving the ア ン テ ナ signal received by the first polarization antenna corresponding to the transmission pulse and outputting a second observation data sequence;
First data used for polarimetry observation and second data used for moving object detection are selected from the first observation data sequence and the second observation data sequence,
An observation method, comprising: generating a polarimetric SAR image from the first data; and generating a moving object detection image from the second data.

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