JP5286877B2 - Radio monitoring device - Google Patents

Description

  The present invention relates to a radio wave monitoring device that detects and monitors radio waves transmitted from a satellite placed in a geosynchronous orbit in space.

  Various satellites such as broadcasting satellites, communication satellites, observation satellites (including meteorological satellites) that perform observation missions such as meteorological observations, etc. are placed on geostationary orbit. Communicate information data and telemetry / commands with ground communication stations such as small earth stations and mobile stations. The radio waves transmitted from these various satellites have been allocated lines so that they do not interfere with each other, but nowadays, the number of satellites has increased, the frequency band used has been further subdivided, and spatial and frequency The trend is becoming overcrowded. Due to such overcrowding, there is a need for a system for comprehensively monitoring a radio wave transmitted from an artificial satellite (or an unrecognized artificial satellite) placed on a geostationary orbit on the ground.

  For example, Patent Document 1 describes a conventional radio wave monitoring apparatus that captures and monitors radio waves from a satellite. The conventional radio wave monitoring apparatus described in Patent Document 1 obtains a rectangular or square search area based on the drift range of the satellite, and scans the antenna by a spiral or zigzag search pattern in the search area. It captures and monitors the radio waves from

Japanese Patent Laid-Open No. 11-14296

  According to the conventional radio wave monitoring device described in Patent Document 1, radio waves from a satellite can be captured and monitored by scanning an antenna in a search region based on the drift range of one satellite. It is not considered to monitor the radio waves being transmitted, and it is necessary to consider what type of antenna scanning is performed in order to monitor the radio waves transmitted from multiple satellites placed in geostationary orbit. There was a problem. More specifically, there is a problem that efficient antenna scanning must be performed in order to perform efficient radio wave monitoring in a wide range and a wide band.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to obtain a radio wave monitoring apparatus that can efficiently monitor radio waves transmitted from satellites arranged in geostationary orbit. .

The radio wave monitoring apparatus according to the invention of claim 1 is a radio wave monitoring apparatus that monitors radio waves transmitted from a plurality of satellites arranged at different longitudes on a geostationary orbit, wherein the radio waves transmitted from the satellites. , A measuring device for measuring the spectrum of a received signal received by the power feeding unit, an antenna control device for driving and controlling the antenna directivity direction, and a scan pattern driven and controlled by the antenna control device, A scan condition generation device that generates a scan pattern that is simultaneously performed by combining a movement in the longitude direction along a trajectory and a circular motion centered on a point on a stationary trajectory.

  The radio wave monitoring apparatus according to a second aspect of the present invention is the radio wave monitoring apparatus according to the first aspect of the present invention, wherein the scan condition generation device uses the scan pattern based on the reception frequency band of the radio wave received by the power feeding unit. The speed of movement in the longitude direction and the speed of the circular motion are set.

  The radio wave monitoring apparatus according to a third aspect of the invention is the radio wave monitoring apparatus according to the first aspect of the invention, wherein the scan condition generating device includes a stationary orbit that occurs with a movement from the south latitude side to the north latitude side across the stationary orbit. At the midpoint of the second intersection of the first intersection and the second orbit of the geostationary orbit that accompanies the next movement from the north latitude side to the south latitude side, and further from the south latitude side to the north latitude side. The above-described scan pattern is generated in which a third intersection with a geosynchronous orbit generated with movement occurs.

According to the first to third aspects of the invention, the scan condition generation device generates a scan pattern that is simultaneously performed by combining the movement in the longitude direction along the geostationary orbit and the circular motion centered on the point on the geostationary orbit. In addition, since the antenna directing direction is driven and controlled, it is possible to efficiently monitor radio waves transmitted from satellites arranged in geostationary orbit. Further, since the speed of movement in the longitude direction and the speed of circular motion in the scan pattern are set based on the reception frequency band to be monitored, a beam pattern corresponding to the antenna beam width determined by the reception frequency band can be formed. In addition, the scan pattern includes a first intersection of a stationary trajectory with a movement from the south latitude side to the north latitude side across the stationary orbit, and a stationary orbit that occurs with the movement from the north latitude side to the south latitude side that occurs next. A third intersection with a geosynchronous orbit generated by the movement from the south latitude side to the north latitude side that occurs next to the second intersection point with the second intersection point. In addition, satellite radio wave monitoring in the latitude range can be performed at high speed in the entire range.

Embodiment 1

  A radio wave monitoring apparatus according to Embodiment 1 of the present invention will be described with reference to FIGS. 1 is an external view showing the external appearance of an antenna section of a radio wave monitoring apparatus according to Embodiment 1 of the present invention, and FIG. 2 is a functional block diagram showing the configuration of the radio wave monitoring apparatus according to Embodiment 1 of the present invention. is there. In FIG. 1, reference numeral 1 denotes an antenna primary mirror, 2 a power supply unit provided in front of the antenna main mirror 1, and 3 a stay fixed to the antenna main mirror 1 to support the power supply unit 2. Reference numeral 4 denotes an antenna support portion that supports the antenna primary mirror 1 so as to be rotatable around an elevation angle axis, and reference numeral 5 denotes an antenna base that supports the antenna support portion 4 so as to be rotatable around an azimuth axis. The antenna base 5 and the antenna support unit 3 are provided with an azimuth driving mechanism and an elevation driving mechanism (not shown) so that the antenna directing direction can be directed to an arbitrary azimuth and elevation. The power feeding unit 2 is provided with an XY stage that can be driven in the X-axis and Y-axis directions on a base member fixed to the stay 3, and a plurality of power feeding devices are arranged on the XY stage. In the coordinate system fixed to the base member of the power feeding unit 2 as shown in FIG. 1, the X axis and the Y axis are the Z axis, the axes parallel to the elevation axis are the X axis, the Z axis, and the X axis. The orthogonal direction is the Y axis.

  In FIG. 2, 6 is a plurality of power feeding devices, 7 is a feeding unit driving mechanism including a motor for driving the above-described XY stage and XY stage in the X-axis and Y-axis directions, and 8 is an azimuth and direction of the antenna primary mirror 1. A main mirror drive mechanism composed of a motor or the like that drives the elevation angle, 9 is an antenna control device that drives and controls the power feeding unit drive mechanism 7 and the main mirror drive mechanism 8, and 10 generates a scanning condition in the antenna directivity direction, and the antenna control device 9 is a scan condition generation device that outputs to N. Reference numeral 11 denotes a reception signal switching device that switches the reception signals received by the plurality of power supply devices 6 and outputs them to the subsequent stage, 12 denotes a measurement device that measures the spectrum of the reception signals output from the reception signal switching device 11, and 13 denotes a measurement device. 12 is a recording device that records the received signal spectrum measured by the number 12 in association with the azimuth angle and elevation angle of the antenna directing direction that is driven and controlled by the antenna control device 9.

  Next, the operation of monitoring radio waves transmitted from a plurality of satellites in geostationary orbit by the radio wave monitoring apparatus of the present invention will be described. The scan condition generation device 10 determines a scan pattern suitable for the received frequency band and outputs the scan pattern to the antenna control device 9. The antenna control device 9 outputs a driving command in the antenna directing direction (driving command in the azimuth and elevation directions) so as to trace the input scan pattern, and the power feeding unit driving mechanism 7 and the main mirror driving mechanism 8 are driven according to this command. Is done. The power feeding unit 2 is provided with a power feeding device 6 for each frequency band in order to support multi-frequency reception, and the plurality of power feeding devices 6 are distributed on the XY plane on the XY stage. The power feeding unit driving mechanism 7 moves the power feeding device 6 corresponding to the frequency band of the received signal to be received to the focal position of the antenna primary mirror 1 by driving the XY stage. A reception signal reflected by the antenna primary mirror 1 and received by the power feeding device 6 is input to the measurement device 12 via the reception signal switching device 11, and the measurement device 12 measures the spectrum of the reception signal. The spectrum data of the received signal measured by the measurement device 12 is recorded in the recording device 13 in association with the antenna directivity direction information (azimuth angle and elevation angle) output from the antenna control device 9.

  Next, a scan pattern generated by the scan condition generation device 10 will be described. FIG. 3 is a graph for explaining the drift range of a plurality of satellites on a geostationary orbit. Satellites A to B shown in FIG. 3 are arranged at positions having different longitudes on the geostationary orbit, and the orbit of each satellite is maintained. Depending on the control performance, the drift range is wide and narrow. FIG. 4 is a graph showing a geostationary orbit (almost 30,000 km above the equator) viewed from a radio monitoring apparatus installed in Japan, and 14 is a geostationary orbit represented by an azimuth and an elevation angle. In FIG. 4, the azimuth angle of true south is defined as 180 degrees, and the elevation angle in the zenith direction is defined as 90 degrees. For collecting radio waves transmitted from a geostationary orbit, the radio wave reception angle and reception spectrum of the antenna are recorded by moving the antenna directing direction along the geostationary orbit. In the case of a satellite with poor satellite orbit maintenance accuracy and large drift, such as satellite B in FIG. 3, when the antenna beam width is narrow, it may not be possible to receive radio waves emitted from the satellite correctly. The covered strip area needs to be scanned. FIG. 5 is a graph showing an example of a scan pattern. In FIG. 5, 15 is an antenna beam range, 16 is a scan pattern, and this scan pattern 14 is moved at a constant speed along a stationary orbit 14 and stopped. A circular motion centered on a point on the trajectory 14 is combined and performed simultaneously. The main mirror driving mechanism 8 scans the antenna main mirror 1 linearly along the stationary orbit 14, and at the same time, the power feeding unit driving mechanism 7 causes the power feeding device 6 to have a circle with a predetermined radius centered on the focal position of the antenna main mirror 1. The scan pattern 16 shown in FIG. 5 is obtained by driving the XY stage so as to move circularly at a constant speed. By performing antenna drive control based on such a scan pattern, radio waves transmitted from a satellite having a large drift can be measured. Note that the scan pattern shown in FIG. 5 can also be traced by driving the antenna primary mirror 1 using only the primary mirror drive mechanism 8, but in this case, the power feeding unit drive mechanism 7 is not necessary. Although the number of parts can be reduced, the motor driving load in the primary mirror driving mechanism 8 increases, and it is considered that problems such as an increase in maintenance work and a decrease in reliability may occur.

  FIG. 6 is a graph showing a scan pattern when the power supply device 6 having a high frequency band is used. Since the antenna beam width is generally determined by λ / D (λ is the wavelength and D is the antenna aperture diameter), the antenna beam width becomes narrow when the high-frequency band feeding device 6 is used. As shown in FIG. 6, since the beam width is narrow in the high frequency band, a scan pattern corresponding to the beam width of the power feeding device 6 to be used is calculated by the scan condition generation device 10 and commanded to the antenna control device 9. Thus, the drive speeds of the primary mirror drive mechanism 8 and the power feeding unit drive mechanism 7 are set. In other words, when the power supply device 6 to be received is determined, the scan condition generation device 10 sets the antenna beam width based on the frequency band used by the power supply device 6, and based on the beam width, A scan pattern is generated by setting the speed of movement along 14 and the angular speed of circular motion about one point on the stationary orbit 14. Further, in the scan pattern generated by the scan condition generating device 10, the angular velocity of the circular motion centered on one point on the stationary orbit 14 is set to a predetermined value regardless of the frequency band to be used (received frequency band), The speed of movement along the geostationary orbit 14 may be changed depending on the frequency band to be used (reception frequency band). Furthermore, flexible radio wave monitoring can be performed by providing a parameter for specifying an angle in the range of the longitude direction and the latitude direction. As described above, the scan condition generating device 10 scans in the longitude direction, the speed of movement in the longitude direction, the angle range in the latitude direction (the angle range is determined by the radius of the circular motion), and the latitude direction. A scan pattern in which the angular velocity of the circular motion around one point on the geostationary orbit 14 is set is generated and output. Note that the beam condition generator 10 determines the antenna coordinates of the earth station shown in FIG. 4 from the coordinate system of latitude and longitude used in the scanning range (latitude range and longitude width to be searched) on the geostationary orbit shown in FIGS. It shall have the function to convert into a system (azimuth angle and elevation angle).

  Further, the scan patterns shown in FIG. 5 and FIG. 6 are from the south latitude side (the side indicated by minus latitude in FIGS. 5 and 6) to the north latitude side (the side indicated by plus latitude in FIGS. 5 and 6) across the geostationary orbit. At the midpoint between the first intersection with the geostationary orbit that accompanies the movement to and the second intersection with the geostationary orbit that accompanies the movement from the north latitude side to the south latitude side that occurs next. Based on such a scan pattern, a predetermined longitude range and latitude range are generated by generating a third intersection with a geosynchronous orbit that occurs as the next shift from the south latitude to the north latitude occurs. Satellite radio wave monitoring can be performed at high speed in almost the entire range.

It is an external view showing the external appearance of the antenna part of the radio wave monitoring apparatus according to Embodiment 1 of the present invention. It is a functional block diagram showing the structure of the radio wave monitoring apparatus according to Embodiment 1 of the present invention. It is a graph explaining the drift range of several satellites on a geosynchronous orbit. It is a graph showing a geostationary orbit viewed from a radio wave monitoring apparatus installed in Japan. It is a graph showing an example of a scan pattern. It is a graph which shows a scan pattern at the time of using a power feeder with a high frequency band.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Antenna primary mirror 2 Power feeding part 3 Mobile station 6 Power feeding apparatus 9 Antenna control apparatus 10 Scan condition production | generation apparatus 12 Measuring apparatus 16 Scan pattern

Claims (3)

A radio wave monitoring apparatus for monitoring radio waves transmitted from a plurality of satellites arranged at different longitudes on a geostationary orbit, a power supply unit for receiving radio waves transmitted from the satellites, and receiving by the power supply unit A measurement device for measuring the spectrum of the received signal, an antenna control device for driving and controlling the antenna directivity direction, and a scan pattern that is driven and controlled by the antenna control device. A radio wave monitoring apparatus comprising: a scan condition generation apparatus that generates a scan pattern that is simultaneously performed by combining a circular motion centered on a point.   The scan condition generation device sets the movement speed in the longitude direction and the speed of the circular motion in the scan pattern based on a reception frequency band of a radio wave received by the power feeding unit. The radio wave monitoring apparatus according to 1.   The scan condition generation device includes a first intersection point with a stationary orbit that occurs with the movement from the south latitude side to the north latitude side across the stationary orbit, and a stationary state that occurs with the next movement from the north latitude side to the south latitude side. Generating the scan pattern in which a third intersection point with a geostationary orbit generated along with a movement from the south latitude side to the north latitude side that occurs next is generated at a substantially middle point with the second intersection point with the orbit. The radio wave monitoring apparatus according to claim 1.

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