JP2009074902A - Satellite-mounted antenna pattern measurement method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve problems in conventional antenna pattern measurement methods that the number of times of satellite attitude controlling is very large to require a great deal of measurement time and further they are accompanied by variations in the characteristics of a plurality of earth station installations or measurement errors caused by satellite attitude control errors. <P>SOLUTION: According to this method, a signal of constant electric power is outputted from an artificial satellite by means of a satellite-mounted antenna; the angle of the antenna around its rolling axis is set at a definite value; the angle thereof around its pitching axis is scanned; the level of received electric power of the output signal from the antenna is measured at the earth station installations; azimuth angle cut patterns are produced as many as the station installations, the cut patterns different in elevation angle offset from the artificial satellite based on the set angle of the rolling axis of the satellite and on the installation positions of the station installations; and the plurality of cut patterns are produced by repeating the production while sequentially changing the set angle of the rolling axis of the satellite by means of a difference between elevation angles found when viewing any two of the station installations from the artificial satellite. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an antenna pattern measuring method for an antenna mounted on a satellite. More specifically, by using multiple earth station equipment, the number of satellite attitude control operations can be greatly reduced, and angle error calibration and earth station equipment calibration associated with attitude control errors can be achieved, thereby providing a highly accurate antenna. The present invention relates to a method for realizing pattern measurement.

  As described in Non-Patent Document 1, the method for measuring the antenna pattern of a satellite-mounted antenna according to the conventional technique 1 uses a single earth station equipment to output an output signal of the mounted antenna in a state in which a constant power from the satellite is transmitted. Measure the received power level at, generate azimuth cut patterns with different elevation offsets, and sequentially change the roll axis setting angle by a certain increment or decrement as shown in Fig. 1 to obtain multiple azimuth cut patterns The two-dimensional antenna pattern is measured repeatedly. In this case, the number of times of attitude control of the satellite is extremely increased, and measurement time is required. Furthermore, the influence of the satellite attitude control error can be mentioned as in the conventional technique 2 described later.

  On the other hand, as described in Non-Patent Document 2, the conventional antenna pattern measurement method for satellite-mounted antennas uses a plurality of earth station facilities as shown in FIG. Describes a method for measuring a two-dimensional antenna pattern. However, error factors include variations in characteristics of earth station equipment and satellite attitude control errors.

“Communication Satellite No. 3a (CS-3a) Communication System In-orbit Initial Function Confirmation Test Results, 1988 Autumn Meeting of the Institute of Electronics, Information and Communication Engineers”, Sakamoto et al., B-83, p. B-1-83 “Examination of antenna pattern measurement and evaluation on technical test satellite VIII, Technical report of IEICE,” Suzuki et al., SAT 2006-59, pp. 7-10, Feb. , 2007

  The problem of the prior art 1 is that the number of times of satellite attitude control becomes very large and a long measurement time is required. The problem of the conventional technique 2 is that the problems of the number of times of satellite attitude control and the measurement time of the conventional technique 1 are solved, but there are variations in characteristics of a plurality of earth station facilities and measurement errors due to satellite attitude control errors. .

  The present invention solves the problems of the prior arts 1 and 2, reduces the number of satellite attitude control times, compensates for angle errors associated with attitude control errors, and calibrates the difference in characteristics of earth station equipment, so that it can be mounted on a highly accurate satellite. An object is to provide a method for measuring an antenna pattern.

  In order to achieve the above object, the method according to the present invention is a method of measuring a two-dimensional antenna pattern of a satellite-mounted antenna using a plurality of earth station facilities, and outputting a signal of constant power from an artificial satellite from the satellite-mounted antenna, The angle around the roll axis of the satellite-mounted antenna is set to a constant value, the angle around the pitch axis is scanned, the output signal of the satellite-mounted antenna is measured at the earth station facility, and the artificial satellite A first generation step of generating the same number of azimuth cut patterns with different elevation offsets from the satellite from the set angle of the roll axis of the earth station and the installation position of the earth station, A second generation step of generating a plurality of azimuth cut patterns by sequentially changing the set angle of the roll axis by a constant increase / decrease and repeating the first generation step; A, wherein a constant increment or decrement, the angular elevation difference is equal from any two of said satellites of said plurality of earth stations equipment.

  The cut pattern obtained at this time is shown in FIG. Since the increase / decrease of the set angle of the roll axis and the elevation angle difference from any two artificial satellites of the earth station facility are the same, some cut patterns overlap. At this time, when an angle error due to the satellite attitude error occurs, the conventional technique 2 cannot detect the angle error as shown in FIG. 4, but in the present invention, the angle correction is performed so that the cut patterns of the same elevation angle coincide. Therefore, the relative angular error can be compensated. Further, the difference between the reception levels of these two cut patterns is a difference in characteristics of the earth station equipment, and this can also be compensated.

  However, this method can compensate for the relative azimuth angle error for all the acquired cut patterns, but the difference in elevation angle from the artificial satellite is the same as the characteristic difference of the earth station equipment. Limited to compensation for only two stations.

  Therefore, in the above-described satellite-mounted antenna pattern measurement method, the angle around the pitch axis of the satellite-mounted antenna is set to a constant value, the angle around the roll axis is scanned, and the output signal of the satellite-mounted antenna is output to the earth station equipment. Measure the received power level at, and generate the same number of elevation cut patterns with different azimuth offsets from the satellite from the set angle of the pitch axis of the satellite and the installation position of the earth station. By further adding the third generation step, it is possible to calibrate the earth station equipment. A part of the cut pattern obtained at this time is shown in FIG.

  Here, the point indicated by Δ in the figure is the intersection of the elevation cut pattern acquired by the earth station equipment in the center of the figure and the azimuth cut pattern obtained by the earth station equipment in the upper right part of the figure, Originally the same value. However, when a difference occurs in the characteristics of the earth station equipment, a difference occurs in the reception level according to this difference. Therefore, by canceling out this level difference, it becomes possible to calibrate the characteristics of the two earth station facilities, and by using some and all of the intersections of the cut patterns, all the earth station facilities are calibrated. Is possible.

  In order to achieve the above object, the method according to the present invention is a method for measuring a two-dimensional antenna pattern of a satellite-mounted antenna using a plurality of earth station facilities, and outputting a signal of constant power from the satellite-mounted antenna. The angle around the pitch axis of the satellite-mounted antenna is set to a constant value, the angle around the roll axis is scanned, the output signal of the satellite-mounted antenna is measured at the earth station facility, and the received power level is measured. A first generation step of generating the same number of elevation cut patterns having different azimuth offset amounts from the artificial satellite from the setting angle of the pitch axis of the artificial satellite and the installation position of the earth station facility, and the artificial station A second generation step for generating a plurality of elevation cut patterns is performed by sequentially changing the set angle of the pitch axis of the satellite by a constant increase / decrease and repeating the first generation step. When has there the constant and increment or decrement, in angular orientation angle difference is equal to from any two of said satellites of said plurality of earth stations equipment.

  Also in this case, the angle around the roll axis of the satellite mounted antenna is set to a constant value, the angle around the pitch axis is scanned, and the output power level of the output signal of the satellite mounted antenna is measured by the earth station equipment. A third generation step of generating the same number of azimuth cut patterns having different elevation angle offset amounts from the artificial satellite from the set angle of the roll axis of the artificial satellite and the installation position of the earth station In addition, the earth station equipment can be calibrated.

  The reception power level measurement in the first generation step is a measurement of a power level transmitted from the plurality of earth station facilities to the artificial satellite and received by the antenna mounted on the artificial satellite. It is also preferable that there is.

  The satellite-mounted antenna pattern measuring method of the present invention uses a plurality of earth station equipments to greatly reduce the number of satellite attitude controls, increase and decrease the set angle of the roll axis (or pitch axis), and the earth station. By making the elevation angle difference (or azimuth angle difference) from any two satellites of the equipment the same, it is possible to compensate for satellite attitude error and calibrate the characteristic deviation of the earth station equipment, and to measure the antenna pattern with high accuracy. Is realized.

  FIG. 6 shows a conceptual diagram of the satellite-borne antenna pattern measurement method according to the first embodiment of the present invention. In a state where a constant power signal is output from the onboard antenna from the satellite a on the geostationary orbit, the roll axis of the satellite a is set to a predetermined angle, and control is performed so as to scan the angle around the pitch axis The received power level is measured by the earth station equipment b1 to bn where the output signals of the satellite mounted antennas are installed at two or more different points. From the setting angle of the roll axis of the artificial satellite and the installation position of the earth station equipment b1 to bn The same number of azimuth cut patterns c1-1 to cn-1 with different elevation offsets from the satellite are generated as with the earth station facilities b1 to bn, and the set angle of the roll axis is sequentially changed by a certain increase / decrease, Is a method of measuring a two-dimensional antenna pattern by repeating (m-1) generations of azimuth cut patterns c1-2 to cn-2,..., C1-m to cn-m. Setting Elevation difference from any two of the satellites a of time the increment or decrement and the earth station equipment b1~bn is satellite antenna pattern measurement method is the same.

  In the case of FIG. 6, n = 3 (three earth station facilities), m = 3 (the azimuth cut pattern is acquired three times), and from the artificial satellite a of the earth station facilities b1 and b3. The elevation angle difference is the same.

  At this time, the cut patterns c3-1 and c1-2, and c3-2 and c1-3 have the same elevation angle offset amount, and therefore match if the satellite attitude control error is zero. An example of the measured cut pattern is shown in FIG. 7, and it can be confirmed that the two do not match due to the satellite attitude control error and the characteristic difference between the earth station facilities b1 and b3. The angle error here corresponds to the azimuth angle error, and the level difference corresponds to the characteristic difference of the earth station equipment. Therefore, as shown in FIG. Thus, the angle error and the level difference can be compensated.

  FIG. 9 shows a conceptual diagram of the satellite mounted antenna pattern measuring method according to the second embodiment of the present invention. In the satellite-mounted antenna pattern measuring method of the first embodiment, the pitch axis of the artificial satellite a is set to a predetermined angle, and control is performed so as to scan the angle around the roll axis. The received power level is measured by the earth station facilities b1 to bn installed at the different points, and the azimuth offset from the satellite is determined from the set angle of the pitch axis of the artificial satellite a and the installation positions of the earth station facilities b1 to bn. The same number of elevation cut patterns d1 to dn as the earth station facilities b1 to bn are generated, and the obtained cut patterns c1-1 to cn-1, ..., c1-m to cn-m, d1 to dn This is a satellite-mounted antenna pattern measurement method for calibrating the reception characteristics of the earth station facilities b1 to bn by comparing reception levels.

  In the case of FIG. 9, as in FIG. 6, n = 3 (three earth station facilities) and m = 3 (the number of azimuth cut pattern acquisition times is three), and the artificial of the earth station facilities b1 and b3 The elevation angle difference from the satellite a is the same.

  In the measurement method of the first embodiment, it is possible to compensate for the relative azimuth error with respect to all of the acquired cut patterns c1-1 to cn-1,..., C1-m to cn-m. However, the characteristic difference between the earth station facilities b1 to bn is limited to compensation only for two stations having the same elevation angle difference from the artificial satellite a. Therefore, in the measurement method of the second embodiment, since the reception levels are the same at the intersections of the cut patterns c3-1, c1-2, and d2 indicated by Δ shown in FIG. 9, the earth station facilities b1, b2, b3 It is possible to compensate for the characteristics of The measured elevation cut pattern c1-2 and azimuth cut pattern d2 are shown in FIG. In the figure, Δ is an angle corresponding to the intersection of each of c1-2 and d2, and the characteristics of the earth station facilities b1 and b2 can be compensated by canceling these reception level differences.

  The satellite mounted antenna measurement method according to the third and fourth embodiments of the present invention is the same as the mounted antenna measurement method according to the first and second embodiments of the present invention, and includes a pitch axis, a roll axis, and an elevation angle orthogonal to each other. The azimuth is switched.

  Moreover, both the azimuth angle error and the elevation angle error can be compensated by carrying out the methods of the first and third embodiments of the present invention and taking the average of the measurement results of both.

  The satellite mounted antenna pattern measuring method according to the fifth embodiment of the present invention realizes a receiving antenna measuring method. Therefore, the direction of the signal is changed, transmitted from the earth station facilities b1 to bn, and the reception level is measured by the artificial satellite a. In this case, it is necessary to transmit signals at different frequencies in the earth station facilities b1 to bn. However, the operating frequency band of the satellite-mounted antenna is a microwave / millimeter wave band (GHz order), but can be separated. Since the frequency band is a khz order which is a frequency band between adjacent channels, it can be said that the frequency characteristics at the time of evaluation can be ignored.

  Moreover, all the embodiment described above shows the present invention exemplarily, and does not limit the present invention, and the present invention can be implemented in other various modifications and changes. Therefore, the scope of the present invention is defined only by the claims and their equivalents.

It is the relationship between the earth station equipment and the cut pattern to be acquired in the antenna pattern measurement method of Prior Art 1. It is the relationship between the earth station equipment and the cut pattern to be acquired in the antenna pattern measurement method of Prior Art 2. It is the relationship between the earth station equipment and the cut pattern to be acquired in the antenna pattern measurement method that solves the problems of the prior art. It is a conceptual diagram (left: conventional, right: the present invention) of angle error compensation. It is a conceptual diagram of different earth station equipment calibration. It is a conceptual diagram of the satellite mounting antenna pattern measuring method which concerns on the 1st Embodiment of this invention. It is an example of the measured cut pattern. It is an example of the cut pattern which performed angle compensation and reception level compensation. It is a conceptual diagram of the satellite mounting antenna pattern measuring method which concerns on the 2nd Embodiment of this invention. It is an example of the measured elevation angle and azimuth cut pattern.

Explanation of symbols

a Artificial satellites b1 to bn Earth station equipment c1-1 to c1-m Azimuth cut patterns obtained when the roll angle is set in the earth station equipment b1 cn-1 to cn-m Roll angles obtained from the earth station equipment bn Azimuth cut pattern at the time of setting d1 to dn Elevation angle cut pattern obtained by the earth station facilities b1 to bn

Claims (5)

In a method of measuring a two-dimensional antenna pattern of a satellite-mounted antenna using a plurality of earth station facilities,
A constant power signal is output from the satellite-mounted antenna from the artificial satellite, the angle around the roll axis of the satellite-mounted antenna is set to a constant value, the angle around the pitch axis is scanned, and the output signal of the satellite-mounted antenna is A reception power level is measured by the earth station facility, and an azimuth cut pattern having a different elevation angle offset amount from the artificial satellite is determined from the roll axis setting angle of the satellite and the installation position of the earth station facility. A first generation step of generating the same number as
A second generation step of generating a plurality of azimuth cut patterns by sequentially changing the set angle of the roll axis of the artificial satellite by a constant increase / decrease and repeating the first generation step;
The satellite-mounted antenna pattern measuring method, wherein the constant increase / decrease amount is equal to an elevation angle difference between any two satellites of the plurality of earth station facilities.   The angle around the pitch axis of the satellite-mounted antenna is set to a constant value, the angle around the roll axis is scanned, the received signal level of the output signal of the satellite-mounted antenna is measured by the earth station facility, and the artificial satellite And a third generation step of generating the same number of elevation cut patterns having different azimuth offset amounts from the artificial satellite from the setting angle of the pitch axis and the installation position of the earth station equipment. The satellite mounted antenna pattern measuring method according to claim 1. In a method of measuring a two-dimensional antenna pattern of a satellite-mounted antenna using a plurality of earth station facilities,
A constant power signal is output from the satellite-mounted antenna from the artificial satellite, the angle around the pitch axis of the satellite-mounted antenna is set to a constant value, the angle around the roll axis is scanned, and the output signal of the satellite-mounted antenna is The earth station equipment measures the received power level, and calculates the elevation angle cut patterns having different azimuth offset amounts from the artificial satellite from the set angle of the pitch axis of the satellite and the installation position of the earth station equipment. A first generation step of generating the same number as
A second generation step of generating a plurality of elevation angle cut patterns by sequentially changing the set angle of the pitch axis of the artificial satellite by a constant increase / decrease and repeating the first generation step;
A satellite-mounted antenna pattern measuring method, characterized in that the constant increase / decrease and an azimuth difference between any two satellites of the plurality of earth station facilities are equal.   The angle around the roll axis of the satellite-mounted antenna is set to a constant value, the angle around the pitch axis is scanned, the output signal of the satellite-mounted antenna is measured at the earth station facility, and the artificial satellite And a third generation step of generating the same number of azimuth cut patterns having different elevation angle offset amounts from the artificial satellite from the set angle of the roll axis and the installation position of the earth station equipment. The satellite-mounted antenna pattern measuring method according to claim 3.   The reception power level measurement in the first generation step is a measurement of the power level transmitted from the plurality of earth station facilities to the artificial satellite and received by the antenna mounted on the artificial satellite. The satellite mounted antenna pattern measuring method according to any one of claims 1 to 4.