JPH0652299B2 - Radio wave sensor method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention is directed to directivity control of a broadcasting antenna for accurately directing a broadcasting antenna mounted on a broadcasting satellite in a geostationary orbit to a service area on the earth. Regarding a radio wave sensor method for detecting a deviation of a pointing direction from a predetermined direction based on a result of receiving a beacon wave transmitted from a beacon station on the earth by a broadcasting satellite as a reference to obtain a pointing direction control signal, In particular, the beacon station can be installed at any point within the service area, and the beacon wave received by sharing the broadcasting antenna can be separated without degrading the characteristics of the broadcasting wave guide system. It is a thing.

(Prior Art) The service area on the earth seen from a broadcasting satellite in a geostationary orbit is an area of an extremely narrow angle range of usually several degrees or less. Therefore, it is necessary to orient the broadcasting antenna mounted on the broadcasting satellite toward the service area on the earth with extremely high accuracy. On the other hand, satellites for this kind of communication, such as broadcasting satellites dedicated to broadcasting, tend to increase in size gradually due to multipurpose, and therefore, the pointing direction of the broadcasting antenna and the attitude of the satellite body are not always in the same direction. It does not always change and produce the same deviation. For example, if the mounting mechanism for fixing the antenna to the satellite body has thermal strain, the pointing direction of the antenna cannot be correctly controlled only by controlling the attitude of the satellite body. Therefore, in order to make the pointing direction of the broadcasting antenna exactly match the direction of the service area, at the same time as the attitude control of the satellite body, separately from this, from the required service area direction of the pointing direction of the antenna itself. It has become necessary to detect the deviation, that is, the deviation, and to control the pointing direction of the antenna itself based on the detection result.

In the directional control of the ground transmission antenna mounted on the satellite as described above, generally, the directional control data is obtained from the result of receiving the beacon wave transmitted from the beacon station on the earth by the ground transmission antenna. The radio wave sensor method is used.

Therefore, as a conventional radio wave sensor system of this type used for controlling the directional direction of a broadcasting antenna mounted on a broadcasting satellite, it is determined by the shape of an input waveguide connected to a feeder in an aperture antenna commonly used for this type of antenna. The waveguide system is configured so that the electromagnetic waves of the fundamental mode and the higher-order modes can be separated from each other, and the fundamental mode in the waveguide system is used for the ground transmission of the broadcast wave, and A radio wave sensor system has been used in which the next mode is used for ground reception of beacon waves for detecting deviation in the pointing direction.

As described above, in the radio wave sensor method in which the fundamental mode and the higher modes of the feeder waveguide system in the aperture antenna are used separately, the electromagnetic radiation level of the fundamental mode shows a peak in the boresight direction of the aperture antenna. , The electromagnetic radiation levels of higher modes show null in the same boresight direction. Therefore, when such a conventional radio wave sensor system is used, the boresight direction of the broadcasting antenna is made to coincide with the direction of the center point of the service area on the earth, and the beacon wave transmitting station is located at the center point of the service area. By installing the satellite, if the satellite attitude and antenna pointing direction are controlled so that the beacon wave higher-order mode reception output from the broadcasting antenna mounted on the satellite is minimized, it will be transmitted as the fundamental mode wave of the broadcasting antenna. It is possible to control so that the broadcast electromagnetic wave is always received at the maximum level in the service area. For example, a television program scheduled to be launched jointly by France and Germany in May 1986, reported by JDBuechs et al. At the 12th International Television System Symposium held in Montreux, Switzerland in May 1981. The above-mentioned radio wave sensor system is used for the directional control of the broadcasting antenna in the broadcasting satellite TVSAT.

(Problems to be Solved by the Invention) However, as described above, the beacon wave reception output of the higher-order mode extracted from the waveguide system connected to the power feeder in the satellite-borne broadcasting aperture antenna becomes null. In the conventional radio wave sensor system in which the directional control of the broadcasting antenna is performed as described above, various drawbacks described below can be pointed out.

(1) Of the reception output of the beacon wave transmitted from the beacon station on the earth by the broadcasting antenna, the extraction of the higher-order mode output of the antenna feeding waveguide system from the fundamental mode output is the feeding waveguide. Will be done by the system. Therefore, as a mode separation waveguide system, the received beacon wave of the higher mode is not separated and passed, but the beacon wave of the basic mode is passed but the higher order is transmitted so that the broadcast wave of the basic mode is passed. It is necessary to provide a waveguide with a thin tube diameter so as not to pass the mode beacon wave. Therefore, in order to allow the broadcast wave of the fundamental mode to pass through the waveguide having a thin tube diameter so as not to pass the beacon wave of the higher order mode, the frequency between the beacon wave frequency and the broadcast wave frequency is Since it is necessary to maintain a constant frequency relationship, which limits the allocation of beacon wave frequencies, this greatly impedes beacon frequency allocation. Further, in the frequency allocation, if the usable beacon wave frequency does not maintain the above-mentioned constant frequency relationship with the broadcast wave frequency, the beacon wave cannot be used for the directional control of the broadcasting antenna. become.

(2) In the conventional radio wave sensor system in which the boresight direction for the fundamental mode broadcast wave of the broadcasting antenna matches the boresight direction for the fundamental mode beacon wave, a beacon station is installed at the center point of the broadcast wave service area. However, there is a case where the beacon station cannot be actually installed in the required area due to the problem of the ground wireless station and the topographical problem such as the location being located on the ocean.

(3) Since the waveguide circuit for mode separation as described above is required, the configuration of the feeding waveguide system of the aperture antenna for broadcasting becomes complicated, and it is difficult to fix the feeding unit to the satellite body. When a structural antenna is mounted, the structural design and thermal design of the pole for supporting the power feeding portion having a complicated structure located at the tip together with the antenna becomes extremely complicated.

(4) As described above, the broadcast wave passes through the waveguide circuit using the waveguide having a narrow tube diameter for mode separation, so that the transmission characteristics of the broadcast wave deteriorate.

The object of the present invention is to eliminate the numerous technical drawbacks listed above due to the mode separation of the received beacon waves in the conventional radio wave sensor system, in order to eliminate all the technical drawbacks. The system is not touched at all, and it is necessary and sufficient control for the pointing direction control of the broadcasting antenna by using the received beacon wave separated from the broadcast wave transmission system after the output end of the feeding waveguide that reached the satellite body. The purpose is to provide a radio wave sensor system that can obtain usage data.

That is, the radio wave sensor method according to the present invention is a radio wave sensor method in which control data for accurately directing a broadcasting antenna mounted on a satellite in a geostationary orbit to a service area on the earth is transmitted from a beacon station on the earth. A plurality of beacon waves with the same frequency but different polarizations are received by the broadcasting antenna mounted on the satellite, and the frequency is separated from the broadcast wave transmission system by the filter connected to the output end of the satellite body of the power feeding waveguide, and the required The processing of the relationship between the polarization of the beacon wave and the reception level is performed by a predetermined processing matrix in accordance with the algorithm described in (1) above to obtain the antenna pointing direction control data. Based on the result of receiving the beacon wave transmitted from the beacon station on the earth as a reference by the antenna In the radio wave sensor method for detecting the deviation from the reference direction of the directivity direction, a plurality of beacon waves having different polarizations transmitted in time series from the beacon station are received by the antenna, and the reception level of each beacon wave is received. Based on the level change caused by the change in the directional direction, obtain an equi-level line corresponding to the reception level of the beacon wave after the change on the radiation pattern corresponding to the beacon wave of each polarization of the antenna, The intersection of all the equal level lines obtained for each beacon wave is the beacon station direction after the change, and the deviation of the pointing direction from the reference direction is detected based on the change in the beacon station direction on the radiation pattern. It is characterized by doing so.

(Operation) Therefore, in the radio wave sensor system according to the present invention,
As long as they can be transmitted and received by the same aperture antenna, there is no restriction on the frequency relationship between the broadcast wave and the beacon wave, and since the mode separation waveguide circuit is not used, it is transmitted from the satellite-mounted broadcast antenna. The generated broadcast wave is not subject to characteristic deterioration due to the configuration of the antenna feeding waveguide system.

Further, in the radio wave sensor system according to the present invention, since the antenna pointing direction control data is obtained based on the polarization characteristics at the beacon frequency of the satellite broadcasting antenna, the beacon station installation point on the earth is set to the broadcasting bore. Beacon stations can be installed at any point as long as they do not need to match the site direction and do not deviate significantly from the service area.

(Example) Hereinafter, the present invention will be described in detail with reference to the drawings.

First, FIG. 1 shows the principle configuration of a radio wave sensor system according to the present invention. The radio wave sensor system having the illustrated configuration includes a beacon station 1 installed on the earth, a broadcasting antenna 2 mounted on a satellite in a geostationary orbit, a broadcasting repeater 3 commonly used for broadcasting satellites, and an antenna reception output beacon wave. Signal processing device 4 for forming a directional control signal based on the data of the antenna directional deviation obtained by the above processing and an attitude control device 5 for controlling the attitude and the directional direction of the satellite body and the antenna itself. ing. Further, the beacon station 1 on the ground generates the polarization number transmitter 6 that transmits the polarization number a assigned to each of the plurality of types of polarizations of the transmitted beacon waves as an identification signal, and generates the carrier wave of the beacon frequency. Polarization number modulator 7, which modulates with wave number a,
A beacon transmitter 8 that amplifies and transmits the modulated beacon wave b, a polarization variable antenna 9 that can variably control the polarization formed by the transmission beacon wave c, and a transmission wave of the polarization corresponding to the polarization number a are obtained. As described above, the polarization controller 10 sends out a control signal d for controlling the polarization variable antenna 9, and the polarization variable antenna 9 has a perfect right-handed circular polarization according to the control signal d from the polarization controller 10. A beacon wave e of an elliptically polarized wave including a wave, a completely left-handed circularly polarized wave and a horizontally and vertically linearly polarized wave in which the axial ratio and the inclination of the principal axis are arbitrarily set is emitted. The polarization number a for identifying each polarization of the transmitted beacon wave e, for example, 1, 2, ..., 7, 8 is repeatedly generated from the polarization number transmitter 6 as a time series signal having a cycle of 1 second, for example. , The polarization controller 10 corresponding to each polarization number a.
According to the control signal d transmitted from the polarization variable antenna 9
The polarization of the transmitted beacon wave e radiated from is, for example, a perfect right-hand circular polarization for polarization number 1, a perfect left-hand circular polarization for polarization number 2, and a polarization number 3. On the other hand, it changes in time series such as horizontal polarization. Each polarization number a is coded, and the polarization number modulator 7 modulates the carrier wave of the beacon frequency in an appropriate manner.

On the other hand, the satellite-equipped broadcasting antenna 2 is, for example, an aperture antenna composed of a feeding horn 11 and a reflecting mirror 12,
Broadcast repeater 3 and signal processing device 4 via waveguide 13
Connect to. The broadcast wave repeater 3 is, as is customary for broadcast satellites, a bandpass filter 14 that passes broadcast waves of an uplink frequency, a receiver 15 that receives and amplifies uplink broadcast waves,
A frequency converter 16 for converting the uplink frequency of the broadcast wave to the downlink frequency, a transmitter 17 for amplifying and transmitting the broadcast wave of the downlink frequency, and a bandpass filter 18 for passing the broadcast wave of the downlink frequency. There is. In addition, the signal processing device 4 is connected to the output ends of the waveguides 13 in parallel with the band filters 14 and 18, and detects the band filter 19 that passes the received beacon frequency wave h and the reception level i of the received beacon wave h. Beacon reception level detector 20, polarization number detector 21 that demodulates reception beacon wave h to detect polarization number j corresponding to the polarization of the reception beacon wave, and reception level i of the beacon wave that comes in time series. And polarization number j
Signal processing matrix circuit 22 for processing the data in accordance with a predetermined processing matrix to generate an antenna pointing direction control signal k, and sends the control signal k to the attitude control device 5.

As described above, from the beacon station 1 on the ground, the continuous wave e of the predetermined beacon frequency modulated by the polarization number a for making an arbitrary polarization and identifying the polarization characteristic is directed to the satellite. At the output end of the feeding waveguide 13 of the satellite-mounted broadcasting antenna 2 that has transmitted and received the beacon wave e, a reception output having a level corresponding to the arrival direction and the polarization characteristic of the beacon wave e can be obtained. The input part g of the received beacon wave output to the signal processing device 4 is the output end of the power feeding waveguide 13 similarly to the input / output part of the broadcast wave in the broadcast repeater 3, and receives the received beacon wave e and the transmitted / received broadcast wave. In each case, only the respective frequency components can be input to and output from the feeding waveguide 13 via the bandpass filters 19 and 18 and 14. That is, in the radio wave sensor according to the present invention, the beacon wave and the broadcast wave are separated from each other in the waveguide system such as the connection portion to the power feeding horn 11 of the power feeding waveguide system as in the conventional radio wave sensor method. Not performed, but performed after the waveguide input / output end, which is not related to the waveguide propagation mode.

As described above, the received beacon wave h extracted by frequency separation from the broadcast wave transmission system is supplied to the beacon reception level detector 20 to detect its reception level i, and demodulated by the polarization number detector 21. The polarization number j representing the polarization formed by the received beacon wave h is extracted. Received beacon wave h
The respective information signals of the reception level i and the polarization number j regarding are supplied to the signal processing matrix circuit 22 and processed as follows according to the signal processing matrix preset for the broadcasting antenna 2.

That is, in the signal processing matrix circuit 22, polarizations corresponding to polarizations such as right-hand circular polarization, left-hand circular polarization, and horizontal polarization formed by the beacon wave e from the terrestrial beacon station 1 input as described above. The reception information data of the wave number j and the reception level i corresponding to the polarization number j is processed according to a processing matrix preset based on the principle of antenna pointing direction deviation determination described below, and the arrival of the beacon wave e. Deviation from the reference direction when the beacon station 1 is viewed from the broadcasting antenna 2 when the boresight direction of the broadcasting antenna 2 is accurately directed to the center point of the service area. As described above, the control signal k for correction is sent to the posture control device 5 to perform the required posture control and pointing direction control.

Next, in the radio wave sensor system of the present invention, the principle of determining the above antenna pointing direction deviation from the polarization characteristic of the beacon wave received by the broadcasting antenna and the reception level corresponding to the polarization characteristic will be described. In the radio wave sensor system of the present invention, as a typical example of the radiation pattern at the frequency of the beacon wave e of the aperture antenna forming the satellite-mounted broadcasting antenna 2 on which the antenna pointing direction deviation is determined, the boresight direction of the aperture antenna is The radiation patterns of the perfect right-hand circularly polarized wave and the perfect left-handed circularly polarized wave when directed to the desired center point in the service area are shown by the solid line and the broken line, respectively, as shown in FIG. The radiation pattern shown in the figure represents the manner of change in the relative gain of the aperture antenna with respect to the beacon waves forming the respective polarized waves, with the main axis of the aperture antenna being the coordinate axis, and the direction of the beacon station is indicated by point B. The directions of maximum increase in relative gain in the right-handed circularly polarized radiation pattern shown by the solid line and the left-handed circularly polarized radiation pattern shown by the broken line are indicated by arrows BQ and BP, respectively. Therefore, if the direction of the beacon station seen from the antenna changes from the point B to, for example, the direction of the arrow BP with the change in the boresight pointing direction of the aperture plane antenna, the beacon wave e forms a right-handed radiation pattern with a solid line radiation pattern. If it is a circular polarized wave, the reception level is lowered, and if the beacon wave e is a left-handed circular polarized wave forming a radiation pattern of a broken line, the reception level is increased. If judged together, the direction and magnitude of change in the boresight pointing direction of the aperture antenna can be judged in principle.

That is, when the polarization of the received wave of the aperture plane antenna is sequentially changed from the right-handed circularly polarized wave shown by the solid line to the left-handed circularly polarized wave shown by the broken line in FIG. , BQ ', B from arrow BQ to arrow BP in FIG.
It changes sequentially in the order of Q ″ and BQ. Therefore, point B
If there is a terrestrial beacon station in the direction of, the radiation pattern of the aperture antenna for beacon waves with various polarization characteristics can be measured and confirmed in advance on the ground, and the aperture antenna forming the broadcasting antenna can be obtained. When the direction of
From the polarization represented by the polarization number of the received beacon wave and the change in the reception level corresponding to that polarization, the contour line (contour) corresponding to the received level of the beacon wave after the change on the radiation pattern of each polarization Therefore, the intersection of all the equal-level lines obtained for each beacon wave of each polarization becomes the beacon station direction after the change, and the direction and magnitude of the deviation of the antenna pointing direction, that is, the deviation can be detected. become.

For example, in FIG. 2, the beacon station direction when the antenna is pointing in the reference direction is point B, and the reception levels of the right-handed circular polarization and the left-handed circular polarization at that time are approximately −, respectively.
11 dB and -23 dB. Next, the antenna pointing direction changes and the reception levels of right-handed circular polarization and left-handed circular polarization are-
If it changes to 9 dB and -26 dB, it will be -9 dB for right-handed circular polarization.
The crossing point of the equi-level line of (4) and the equi-level of the left-hand circularly polarized wave of -26 dB, for example, the point B'is the beacon station direction after the change. It should be noted that when the number of polarizations is two, the other intersection B ″ becomes a false value, but when the number of polarizations is three or more, the intersections of all the equal-level lines converge to one point. Since the absolute value of each reception level of the polarized beacon wave also changes with the change of the antenna pointing direction, the polarization of the beacon wave transmitted from the ground beacon station is cyclically repeated and changed sequentially. If the reception level corresponding to the wave is monitored, it is possible to immediately detect the deviation of the antenna pointing direction and easily correct and hold it in a predetermined direction.

(Effects of the Invention) As is clear from the above description, according to the present invention, based on the reception state in the satellite of the beacon wave transmitted from the ground beacon station for the directional control of the broadcasting antenna mounted on the satellite, Regarding the radio wave sensor method that detects the deviation of the antenna pointing direction from the predetermined direction, not only can the ground beacon station be installed at any point in the service area on the earth where the broadcasting antenna should point, but also by the broadcasting antenna. The separation and extraction of the received beacon wave from the broadcast wave transmission system does not deteriorate the broadcast wave transmission characteristics at all. Therefore, the satellite antenna for broadcasting, especially its feeding waveguide system, is used for controlling the antenna pointing direction. It is possible to configure the optimum state for broadcast wave transmission without any restrictions by the radio wave sensor system of Another remarkable effect can be obtained. Although the description has been centered on the broadcast satellite, the present invention is not limited to this, and it goes without saying that the present invention can be applied to a communication satellite.

[Brief description of drawings]

FIG. 1 is a block diagram showing the principle configuration of a radio wave sensor system according to the present invention, and FIG. 2 is a diagram showing a typical example of a radiation pattern that differs depending on the polarization of a beacon wave frequency of a satellite broadcasting antenna. Similarly, FIG. 3 is a diagram showing an example of the change in relative gain in the radiation pattern due to polarization in the maximum increasing direction. DESCRIPTION OF SYMBOLS 1 ... Terrestrial beacon station, 2 ... Broadcast antenna 3 ... Broadcast repeater, 4 ... Signal processing apparatus 5 ... Attitude control apparatus, 6 ... Polarization number transmitter 7 ... Polarization number modulator, 8 ... Beacon transmitter 9 … Polarization variable antenna, 10… Polarization controller 11… Feeding horn, 12… Reflecting mirror 13… Feeding waveguide, 14, 18, 19… Band filter 15… Receiver, 16… Frequency converter 17… Transmitter 20 ... Beacon reception level detector 21 ... Polarization number detector 22 ... Signal processing matrix circuit.

Claims (3)

[Claims] 1. A deviation of the pointing direction from a reference direction is detected based on the result of reception of a beacon wave transmitted from a beacon station on the earth as a reference for controlling the pointing direction of an antenna mounted on a geostationary satellite by the antenna. In the radio wave sensor method, a plurality of beacon waves each of which is transmitted in a time series from a beacon station and having different polarizations are received by the antenna, and based on a level change caused by a change in the pointing direction of the reception level of each beacon wave. Obtaining an equal level line corresponding to the reception level of the beacon wave after the change on the radiation pattern corresponding to the beacon wave of each polarization of the antenna, the each equal level obtained for each beacon wave of the different polarization The beacon station direction after the change at the intersection of all the lines, the beacon station direction on the radiation pattern Telecommunications sensor method being characterized in that to detect the deviation from the reference direction of the pointing direction based on the reduction. 2. By modulating each of the plurality of beacon waves with an identification signal corresponding to each polarization,
The radio wave sensor system according to claim 1, characterized in that information relating to identification of polarization characteristics of the beacon wave is transmitted to the geostationary satellite side. 3. A filter is connected to an output end of a waveguide connected to the antenna so that the beacon wave and the communication wave are separated from each other based on a difference in respective frequencies. The radio wave sensor system according to claim 1 or 2.