CN109343012B

CN109343012B - Active scaler for scaling of double-station SAR system

Info

Publication number: CN109343012B
Application number: CN201811187664.8A
Authority: CN
Inventors: 李亮; 洪峻; 明峰; 孙巍; 王宇; 朱勇涛
Original assignee: Institute of Electronics of CAS
Current assignee: Institute of Electronics of CAS
Priority date: 2018-10-12
Filing date: 2018-10-12
Publication date: 2021-03-19
Anticipated expiration: 2038-10-12
Also published as: CN109343012A

Abstract

The present disclosure provides an active scaler for scaling of a bistatic SAR system, the bistatic SAR system comprising: the SAR receiving system comprises an SAR transmitter, an SAR transmitting antenna, an SAR receiver and an SAR receiving antenna; the active scaler includes: the receiving antenna is used for receiving the signals transmitted by the SAR transmitter through the SAR transmitting antenna; the transmitting antenna transmits the calibration signal to the SAR receiver through the SAR receiving antenna; the receiving antenna servo is used for adjusting the direction of the receiving antenna so that the receiving antenna points to the SAR transmitting antenna; the transmitting antenna servo is used for adjusting the direction of the transmitting antenna so that the transmitting antenna points to the SAR receiving antenna; the numerical control unit controls the directional adjustment of the receiving antenna servo and the transmitting antenna servo; and the radio frequency unit is used for processing the signals received by the receiving antenna and then sending the signals to the transmitting antenna. According to the method, the receiving antenna and the transmitting antenna can be independently adjusted in the pointing direction, the stability of the RCS value of the active scaler under the condition of different double-station angles is guaranteed, and the method is suitable for scaling the double-station SAR system under the condition of different double-station angle configurations.

Description

Active scaler for scaling of double-station SAR system

Technical Field

The disclosure relates to the field of radars, in particular to an active scaler for scaling a two-station SAR system.

Background

Compared with a single-station Synthetic Aperture Radar (SAR), the double-station SAR has stronger detection and identification capabilities on a stealth target, can obtain the cross-sectional area (RCS) of the target, and is more and more concerned and emphasized by domestic and foreign application departments. However, the research on the calibration technology of the two-station synthetic aperture radar is relatively less, and the corresponding calibration equipment of the two-station synthetic aperture radar is less reported because the two-station synthetic aperture radar is not operated on the orbit.

The SAR calibration equipment comprises active calibration equipment and passive calibration equipment, wherein the active calibration equipment mainly refers to an active calibrator, and the passive calibration equipment mainly comprises a three-plane corner reflector, a two-plane corner reflector, a metal flat plate, a metal reflection disc and the like. The single-station SAR system calibration equipment is mature in research, but the single-station SAR system calibration equipment is difficult to directly apply to the double-station SAR system calibration, according to reports, a three-plane corner reflector and a two-plane corner reflector are not suitable for the double-station SAR calibration, a metal flat plate and a metal reflection disc can only be used for the double-station SAR system calibration with a small double-station angle, and for the double-station polarized SAR system, suitable passive calibration equipment is more difficult to find. The active scaler has the advantages of small volume, high radar sectional area, adjustable radar sectional area and the like, is often used as the first choice of SAR scaling equipment, and satellite-borne SAR systems launched at home and abroad almost develop corresponding active scalers to carry out on-orbit scaling

The active scaler designed for the single-station SAR is difficult to be used for scaling of a double-station SAR system, and the active scaler can be suitable for the double-station SAR scaling by increasing the beam width of a receiving and transmitting antenna of the single-station active scaler. However, increasing the beam width brings about the following problems: first, an increase in beam width inevitably leads to a decrease in antenna gain, making it difficult to obtain a higher radar cross-sectional area. Secondly, the increase of the beam width can cause the reduction of the antenna isolation between receiving and transmitting, in order to avoid the self-excitation of the system, the system gain is inevitably reduced, the radar sectional area of the active scaler is also reduced, and the provision of a higher radar sectional area is difficult.

Disclosure of Invention

Technical problem to be solved

The present disclosure provides an active sealer for scaling of a two-station SAR system to at least partially solve the technical problems set forth above.

(II) technical scheme

According to an aspect of the present disclosure, there is provided an active scaler for scaling of a two-station SAR system, the two-station SAR system comprising: the SAR receiving system comprises an SAR transmitter, an SAR transmitting antenna, an SAR receiver and an SAR receiving antenna; wherein the active scaler includes: a receiving antenna for receiving the signals transmitted by the SAR transmitter through the SAR transmitting antenna; the transmitting antenna is used for receiving the transmitted calibration signal to the SAR receiver through the SAR receiving antenna; a receiving antenna servo used for adjusting the direction of the receiving antenna so as to enable the receiving antenna to point to the SAR transmitting antenna; the transmitting antenna servo is used for adjusting the direction of the transmitting antenna so that the transmitting antenna points to the SAR receiving antenna; the numerical control unit controls the directional adjustment of the receiving antenna servo and the transmitting antenna servo; the radio frequency unit is used for processing the signals received by the receiving antenna and then sending the signals to the transmitting antenna; and the power distribution unit supplies power for the receiving antenna servo unit, the transmitting antenna servo unit, the numerical control unit and the radio frequency unit.

Preferably, the radio frequency unit performs four kinds of polarization calibration through switch control, including HH polarization calibration, HV polarization calibration, VH polarization calibration, and VV polarization calibration; when the active scaler performs HH polarization scaling, the switch for receiving the V polarization signal is closed, the switch for transmitting the V polarization signal is closed, the switch for receiving the H polarization signal is opened, and the switch for transmitting the H polarization signal is opened; when the active scaler performs HV polarization scaling, the switch for receiving the V polarization signal is closed, the switch for transmitting the H signal is closed, the switch for receiving the H polarization signal is opened, and the switch for transmitting the V polarization signal is opened; when the active scaler performs VH polarization scaling, the switch for receiving the H polarization signal is closed, the switch for transmitting the V polarization signal is closed, the switch for receiving the V polarization signal is opened, and the switch for transmitting the H polarization signal is opened; and when the active scaler performs VV polarization scaling, the switch for receiving the H polarization signal is closed, the switch for transmitting the H polarization signal is closed, the switch for receiving the V polarization signal is opened, and the switch for transmitting the V polarization signal is opened.

Preferably, the numerical control unit further includes: and the timing starting equipment controls the servo rotation of the receiving antenna and the servo rotation of the transmitting antenna according to the configuration condition of the double-station SAR system, so that the receiving antenna points to the SAR transmitting antenna, and the transmitting antenna points to the SAR receiving antenna.

Preferably, the directional adjustment of the receiving antenna servo comprises: azimuth pointing adjustment and pitch pointing adjustment.

Preferably, the directional adjustment of the transmit antenna servo comprises: azimuth pointing adjustment and pitch pointing adjustment.

Preferably, the receiving antenna and the transmitting antenna are both high-isolation dual-polarized antennas.

Preferably, the power distribution unit is a wind energy-solar energy complementary power supply system.

(III) advantageous effects

From the above technical solution, it can be seen that the active scaler for the two-station SAR system of the present disclosure has at least one or some of the following beneficial effects:

(1) in the present disclosure, each unit constitutes an organic whole, and does not need to be assembled separately before each operation.

(2) The receiving antenna servo and the transmitting antenna servo in the disclosure can independently adjust the directions of the receiving antenna and the transmitting antenna, ensure the stability of the RCS value of the active scaler under the condition of different double-station angles, and are suitable for calibrating the double-station SAR system under the condition of different double-station angle configurations.

(3) The receiving antenna and the transmitting antenna adopt high-isolation dual-polarized antennas, the calibration of four polarization working modes of HH, HV, VH and VV of the double-station SAR system can be realized through the switch control in the radio frequency unit, and the defect that the calibration of different polarization states of the double-station SAR cannot be realized by passive calibration equipment is overcome.

(4) The numerical control unit has the functions of timing starting and automatic operation, equipment is started at regular time and operates automatically according to the satellite over-the-top time, calibration of the SAR system under the unattended condition is achieved, and the use convenience is greatly improved.

Drawings

Fig. 1 is a schematic structural diagram of an active scaler for a two-station SAR system according to a first embodiment of the present disclosure.

Detailed Description

For the purpose of promoting a better understanding of the objects, aspects and advantages of the present disclosure, reference is made to the following detailed description taken in conjunction with the accompanying drawings.

Certain embodiments of the present disclosure will now be described more fully hereinafter with reference to the accompanying drawings, in which some, but not all embodiments of the disclosure are shown. Indeed, various embodiments of the disclosure may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will satisfy applicable legal requirements.

In a first exemplary embodiment of the present disclosure, an active sealer for scaling of a two-station SAR system is provided. Fig. 1 is a schematic structural diagram of an active scaler for scaling of a two-station SAR system according to a first embodiment of the present disclosure. As shown in figure 1 of the drawings, in which,

the two-station SAR system includes: the SAR receiving system comprises an SAR transmitter, an SAR transmitting antenna, an SAR receiver and an SAR receiving antenna; the active scaler proposed by the present disclosure includes: the system comprises a receiving antenna, a transmitting antenna, a receiving antenna servo, a transmitting antenna servo, a numerical control unit, a radio frequency unit and a power distribution unit; the receiving antenna receives signals transmitted by the SAR transmitter through the SAR transmitting antenna; the transmitting antenna transmits a calibration signal, and the SAR receiver receives the calibration signal through the SAR receiving antenna; the receiving antenna servo is used for adjusting the direction of the receiving antenna so that the receiving antenna points to the SAR transmitting antenna; the transmitting antenna servo is used for adjusting the direction of the transmitting antenna so that the transmitting antenna points to the SAR receiving antenna; the numerical control unit controls the directional adjustment of the receiving antenna servo and the transmitting antenna servo; the radio frequency unit processes signals received by the receiving antenna and sends the signals to the transmitting antenna; the power distribution unit supplies power for the receiving antenna servo unit, the transmitting antenna servo unit, the numerical control unit and the radio frequency unit.

The receiving antenna and the transmitting antenna are high-isolation dual-polarized antennas. Meanwhile, the radio frequency unit can carry out four kinds of polarization calibration through switch control, including HH polarization calibration, HV polarization calibration, VH polarization calibration and VV polarization calibration; when the HH polarization is calibrated, the switch for receiving the V polarization signal is closed, the switch for transmitting the V polarization signal is closed, the switch for receiving the H polarization signal is opened, and the switch for transmitting the H polarization signal is opened; when HV polarization calibration is carried out, a switch for receiving the V polarization signal is closed, a switch for transmitting the H polarization signal is closed, a switch for receiving the H polarization signal is opened, and a switch for transmitting the V polarization signal is opened; when VH polarization calibration is carried out, a switch for receiving H polarization signals is closed, a switch for transmitting V polarization signals is closed, a switch for receiving V polarization signals is opened, and a switch for transmitting H polarization signals is opened; and when the VV polarization is calibrated, closing the switch for receiving the H polarization signal, closing the switch for transmitting the H polarization signal, opening the switch for receiving the V polarization signal and opening the switch for transmitting the V polarization signal. In the method, the receiving antenna and the transmitting antenna both adopt high-isolation dual-polarized antennas, the calibration of four polarization working modes of HH, HV, VH and VV of the double-station SAR system is realized through the switch control in the radio frequency unit, and the defect that the passive calibration equipment cannot realize the calibration of different polarization states of the double-station SAR system is overcome.

As a specific implementation manner, the signal processing performed by the rf unit on the signal received by the receiving antenna mainly includes processing such as amplification, filtering, delay, and gain calibration.

As a specific implementation mode, the power distribution unit is a wind energy-solar energy complementary power supply system which can be powered by both solar energy and wind energy, and the problem caused by frequent charging due to the adoption of a storage battery for power supply is avoided.

As a specific implementation manner, the numerical control unit further includes: and starting the equipment at a fixed time, and controlling the servo rotation of the receiving antenna and the servo rotation of the transmitting antenna according to the configuration condition of the double-station SAR system so that the receiving antenna points to the SAR transmitting antenna and the transmitting antenna points to the SAR receiving antenna. And starting the active scaler device at regular time and ensuring the automatic operation of the active scaler according to the working parameters of the SAR system and the satellite over-top time.

As a specific embodiment, the directional adjustment of the receiving antenna servo comprises: and the azimuth direction and the elevation direction are adjusted, so that the receiving antenna of the active scaler points to the transmitting antenna of the SAR system at high precision. The directional adjustment of the transmit antenna servo comprises: and the azimuth direction and the elevation direction are adjusted, so that the transmitting antenna of the active scaler points to the receiving antenna of the SAR system at high precision.

So far, the embodiments of the present disclosure have been described in detail with reference to the accompanying drawings. It is to be noted that, in the attached drawings or in the description, the implementation modes not shown or described are all the modes known by the ordinary skilled person in the field of technology, and are not described in detail. Further, the above definitions of the various elements and methods are not limited to the various specific structures, shapes or arrangements of parts mentioned in the examples, which may be easily modified or substituted by those of ordinary skill in the art.

From the above description, those skilled in the art should have clear recognition of the active scaler for scaling of the bistatic SAR system of the present disclosure.

In summary, the present disclosure provides an active scaler for radiation scaling and polarization scaling of a two-station Synthetic Aperture Radar (SAR) system, which can perform independent directional adjustment on a receiving antenna and a transmitting antenna, ensure the stability of the RCS value of the active scaler under different two-station angles, and is suitable for scaling the two-station SAR system under different two-station angle configuration conditions.

It should also be noted that directional terms, such as "upper", "lower", "front", "rear", "left", "right", and the like, used in the embodiments are only directions referring to the drawings, and are not intended to limit the scope of the present disclosure. Throughout the drawings, like elements are represented by like or similar reference numerals. Conventional structures or constructions will be omitted when they may obscure the understanding of the present disclosure.

And the shapes and sizes of the respective components in the drawings do not reflect actual sizes and proportions, but merely illustrate the contents of the embodiments of the present disclosure. Furthermore, in the claims, any reference signs placed between parentheses shall not be construed as limiting the claim.

Unless otherwise indicated, the numerical parameters set forth in the specification and attached claims are approximations that can vary depending upon the desired properties sought to be obtained by the present disclosure. In particular, all numbers expressing quantities of ingredients, reaction conditions, and so forth used in the specification and claims are to be understood as being modified in all instances by the term "about". Generally, the expression is meant to encompass variations of ± 10% in some embodiments, 5% in some embodiments, 1% in some embodiments, 0.5% in some embodiments by the specified amount.

Furthermore, the word "comprising" does not exclude the presence of elements or steps not listed in a claim. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements.

The use of ordinal numbers such as "first," "second," "third," etc., in the specification and claims to modify a corresponding element does not by itself connote any ordinal number of the element or any ordering of one element from another or the order of manufacture, and the use of the ordinal numbers is only used to distinguish one element having a certain name from another element having a same name.

Similarly, it should be appreciated that in the foregoing description of exemplary embodiments of the disclosure, various features of the disclosure are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure and aiding in the understanding of one or more of the various disclosed aspects. However, the disclosed method should not be interpreted as reflecting an intention that: that is, the claimed disclosure requires more features than are expressly recited in each claim. Rather, as the following claims reflect, disclosed aspects lie in less than all features of a single foregoing disclosed embodiment. Thus, the claims following the detailed description are hereby expressly incorporated into this detailed description, with each claim standing on its own as a separate embodiment of this disclosure.

The above-mentioned embodiments are intended to illustrate the objects, aspects and advantages of the present disclosure in further detail, and it should be understood that the above-mentioned embodiments are only illustrative of the present disclosure and are not intended to limit the present disclosure, and any modifications, equivalents, improvements and the like made within the spirit and principle of the present disclosure should be included in the scope of the present disclosure.

Claims

1. An active scaler for scaling for a bi-site SAR system, the bi-site SAR system comprising: the SAR receiving system comprises an SAR transmitter, an SAR transmitting antenna, an SAR receiver and an SAR receiving antenna; wherein the active scaler includes:

a receiving antenna for receiving the signals transmitted by the SAR transmitter through the SAR transmitting antenna;

the transmitting antenna is used for receiving the transmitted calibration signal to the SAR receiver through the SAR receiving antenna;

a receiving antenna servo used for adjusting the direction of the receiving antenna so as to enable the receiving antenna to point to the SAR transmitting antenna;

the transmitting antenna servo is used for adjusting the direction of the transmitting antenna so that the transmitting antenna points to the SAR receiving antenna;

the numerical control unit controls the directional adjustment of the receiving antenna servo and the transmitting antenna servo;

the radio frequency unit is used for processing the signals received by the receiving antenna and then sending the signals to the transmitting antenna;

and the power distribution unit supplies power for the receiving antenna servo unit, the transmitting antenna servo unit, the numerical control unit and the radio frequency unit.

2. The active sealer according to claim 1, wherein the radio frequency unit performs four kinds of polarization scaling by switching control, including HH polarization scaling, HV polarization scaling, VH polarization scaling, VV polarization scaling;

when the active scaler performs HH polarization scaling, the switch for receiving the V polarization signal is closed, the switch for transmitting the V polarization signal is closed, the switch for receiving the H polarization signal is opened, and the switch for transmitting the H polarization signal is opened;

when the active scaler performs HV polarization scaling, the switch for receiving the V polarization signal is closed, the switch for transmitting the H signal is closed, the switch for receiving the H polarization signal is opened, and the switch for transmitting the V polarization signal is opened;

when the active scaler performs VH polarization scaling, the switch for receiving the H polarization signal is closed, the switch for transmitting the V polarization signal is closed, the switch for receiving the V polarization signal is opened, and the switch for transmitting the H polarization signal is opened;

and when the active scaler performs VV polarization scaling, the switch for receiving the H polarization signal is closed, the switch for transmitting the H polarization signal is closed, the switch for receiving the V polarization signal is opened, and the switch for transmitting the V polarization signal is opened.

3. The active sealer of claim 1, wherein the numerical control unit further comprises: and the timing starting equipment controls the servo rotation of the receiving antenna and the servo rotation of the transmitting antenna according to the configuration condition of the double-station SAR system, so that the receiving antenna points to the SAR transmitting antenna, and the transmitting antenna points to the SAR receiving antenna.

4. The active sealer of claim 1, wherein the directional adjustment of the receive antenna servo comprises: azimuth pointing adjustment and pitch pointing adjustment.

5. The active sealer of claim 1, wherein the directional adjustment of the transmit antenna servo comprises: azimuth pointing adjustment and pitch pointing adjustment.

6. The active sealer according to claim 1, wherein the receive antenna and the transmit antenna are both high isolation dual polarized antennas.

7. The active sealer according to claim 1, wherein the power distribution unit is a wind-solar complementary power supply system.