Ka-band GEO satellite ground station antenna monopulse tracking control method

Abstract

The application discloses a Ka-band GEO satellite ground station antenna single-pulse tracking control method and belongs to the field of satellite communication ground station antenna tracking control. The application comprises the following steps: connecting an antenna servo device with a single-pulse tracking receiver to obtain the directional sensitivity parameters of a single-pulse tracking system; calculating and setting the judgment threshold of tracking control according to the antenna aperture and tracking frequency points; establishing three arrays with a length of n to store the azimuth error voltage Ua, the elevation error voltage Ue and the total error voltage U respectively; starting the single-pulse tracking; collecting the azimuth error voltage and the elevation error voltage in real time, obtaining the total error voltage U according to the calculation, and performing single-pulse tracking control according to the evaluation error V and the judgment threshold. The application can automatically switch to other tracking modes before the single-pulse tracking fails, can solve the problem that the antenna single-pulse tracking deviates from the satellite main beam due to the deterioration of cross-coupling, and improves the reliability of antenna tracking.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of satellite communication ground station antenna tracking control, in particular to a Ka-band GEO satellite ground station antenna monopulse tracking control method. BACKGROUND

[0002] GEO satellite is about 36,000 kilometers away from the earth, and is widely used due to a series of advantages such as wide coverage, no restriction by ground obstacles, and rapid deployment, and gradually becomes one of the irreplaceable core communication means. With the development of satellite communication technology, Ka-band with wider frequency band and larger communication capacity is more and more applied.

[0003] The approximate frequency range of Ka-band is 30 / 20GHz. For a ground station antenna with large aperture, the beam width of the tracking signal is extremely narrow. Taking a 13m antenna as an example, the beam width of the tracking signal is only 0.07°, so the tracking accuracy of the antenna is required to be high. The Ka-band ground station antenna is usually equipped with a monopulse tracking system, including a monopulse tracking feed network, a monopulse tracking receiver, and an antenna servo device. The monopulse tracking utilizes the antenna pattern of the differential mode electromagnetic field, and uses the characteristics that the axial direction is zero and the off-axis direction has polarity to realize tracking.

[0004] Under normal circumstances, the ground station antenna tracking GEO satellite is continuously working for 24 hours before the regular maintenance time window arrives, and will not be shut down for maintenance unless the equipment fails. As a key indicator of the system, the cross coupling of the output error voltage of the monopulse tracking receiver directly affects the tracking accuracy of the antenna. In addition, due to the drift of the antenna electric axis, the change of the environmental temperature, or the antenna polarization tracking and other factors, the relative phase shift of the sum and difference channels is caused, which makes the cross coupling indicator deteriorate continuously, causes the monopulse tracking accuracy of the antenna to decrease, and even when the azimuth error voltage or the elevation error voltage polarity reverses, the antenna deviates from the main beam of the satellite directly, which causes the communication to be interrupted. SUMMARY

[0005] Therefore, the present application provides a Ka-band GEO satellite ground station antenna monopulse tracking control method, which actively changes to other tracking modes before the antenna pointing deviates from the previous main tracking mode when the monopulse tracking quality decreases, so as to avoid communication interruption and improve the tracking reliability of the antenna.

[0006] To achieve the above object, the technical scheme provided by the present application is as follows:

[0007] A Ka-band GEO satellite ground station antenna monopulse tracking control method, comprising the following steps:

[0008] Step 1, the antenna servo device is connected to the monopulse tracking receiver, aligns the satellite to complete phase calibration, and obtains the directional sensitivity parameter s of the monopulse tracking system;

[0009] Step 2, the antenna servo device calculates and sets the decision threshold of tracking control according to the antenna aperture and the tracking frequency point;

[0010] Step 3, the antenna servo device respectively establishes a length-n azimuth error array, an elevation error array and a total error array, adopts a sequential storage mode, respectively stores the azimuth error voltage Ua, the elevation error voltage Ue transmitted by the monopulse tracking receiver and the total error voltage U calculated by the antenna servo device, and n is not less than 20;

[0011] Step 4, start monopulse tracking;

[0012] Step 5, the antenna servo device collects the azimuth error voltage and the elevation error voltage transmitted by the monopulse tracking receiver in real time, moves the data in the three arrays one position at a time, discards the overflow data, fills the currently collected azimuth error voltage Ua into the last position of the azimuth error array, fills the elevation error voltage Ue into the last position of the elevation error array, and fills the total error voltage U calculated according to into the last position of the total error array;

[0013] Step 6, calculate the average value of the total error array to obtain the evaluation error V:

[0014]

[0015] Step 7, monopulse tracking control is performed according to the evaluation error V and the decision threshold.

[0016] Further, the decision threshold is divided into an alarm threshold T1 and a tracking threshold T2, the alarm threshold T1 is twenty one times of the antenna beam width multiplied by the directional sensitivity parameter s, that is:

[0017]

[0018] The tracking threshold T2 is ten times of the beam width multiplied by the directional sensitivity parameter s, that is:

[0019]

[0020] Wherein, s is the directional sensitivity, the unit is v / °;

[0021] f is the tracking frequency point, the unit is GHz;

[0022] D is the antenna aperture, the unit is m.

[0023] Further, the specific way of step 7 is:

[0024] If the evaluation error V is less than the alarm threshold T1, the antenna continues to perform monopulse tracking;

[0025] If the evaluation error V is greater than the alarm threshold T1 and less than the turn tracking threshold T2, the antenna continues to perform the monopulse tracking, and the antenna servo device prompts the cross-coupling alarm;

[0026] If the evaluation error V is greater than the turn tracking threshold T2, the antenna stops the monopulse tracking, and according to the configuration of the antenna servo device, one of the tracking modes of the step tracking, the memory tracking or the program tracking is entered.

[0027] Due to the above scheme, the present application has the following beneficial effects relative to the background art:

[0028] 1. The present application does not increase the hardware devices, and the azimuth error voltage and the elevation error voltage transmitted by the monopulse tracking receiver are recorded to calculate the total error voltage, so that the evaluation error is obtained, and the monopulse tracking control is realized.

[0029] 2. The present application can solve the problem that the cross-coupling deterioration causes the monopulse tracking to deviate from the satellite beam, and can automatically change to other tracking modes before the tracking state deteriorates, thereby avoiding the communication interruption.

[0030] 3. The present application can improve the tracking reliability of the antenna, and has the advantages of simplicity and practicality, easy implementation and strong universality. BRIEF DESCRIPTION OF DRAWINGS

[0031] Figure 1 It is a composition block diagram of the monopulse tracking system in the embodiment of the present application.

[0032] Figure 2 It is an evaluation error schematic diagram in the embodiment of the present application. DETAILED DESCRIPTION

[0033] The present application will be further described in detail below in combination with the drawings and the specific implementation manner:

[0034] A Ka-band GEO satellite ground station antenna monopulse tracking control method, characterized in that it comprises the following steps:

[0035] Step 1, as shown in the figure, the antenna servo device is connected to the monopulse tracking receiver, aligns the satellite to complete the phase calibration, and obtains the directional sensitivity parameter s of the monopulse tracking system; Figure 1

[0036] Step 2, the antenna servo device calculates and sets the judgment threshold of the tracking control according to the antenna aperture and the tracking frequency point;

[0037] ​Step 3, the antenna servo device respectively establishes the azimuth error array, the elevation error array and the total error array with the length of 20, adopts the sequential storage mode, and stores the azimuth error voltage Ua, the elevation error voltage Ue transmitted by the monopulse tracking receiver and the total error voltage U calculated by the antenna servo device.

[0038] Step 4, the monopulse tracking is started.

[0039] Step 5, the antenna servo device collects the azimuth error voltage and the elevation error voltage transmitted by the monopulse tracking receiver in real time, and moves the data in the three arrays one position at a time, fills the last position of the azimuth error array with the currently collected azimuth error voltage Ua, fills the last position of the elevation error array with the elevation error voltage Ue, and fills the last position of the total error array with the total error voltage U calculated according to .

[0040] Step 6, the average value of the total error array is calculated to obtain the evaluation error V:

[0041]

[0042] Step 7, the monopulse tracking quality tracking control is performed according to the evaluation error V and the judgment threshold.

[0043] Further, the judgment threshold is divided into an alarm threshold T1 and a tracking threshold T2, the alarm threshold T1 is twenty one times of the antenna beam width multiplied by the directional sensitivity parameter s, that is:

[0044]

[0045] The tracking threshold T2 is ten times of the beam width multiplied by the directional sensitivity parameter s, that is:

[0046]

[0047] Wherein, s is the directional sensitivity, and the unit is v / °;

[0048] f is the tracking frequency point, and the unit is GHz;

[0049] D is the antenna aperture, and the unit is m.

[0050] Specifically, in the embodiment, s = 60 v / °, f = 21 GHz, D = 13 m, the alarm threshold T1 is calculated as:

[0051]

[0052] The tracking threshold T2 is:

[0053]

[0054] Further, as shown in Figure 2 The specific way of step 7 is:

[0055] If the evaluation error V < 0.23, the antenna continues to perform the monopulse tracking;

[0056] If the evaluation error 0.23 < V < 0.46, the antenna continues to perform the monopulse tracking, and the antenna servo device prompts the cross-coupling alarm;

[0057] If the evaluation error V > 0.46, the antenna stops the monopulse tracking, and according to the antenna servo device configuration, turns to one of the tracking modes of the step-by-step tracking, the memory tracking or the program tracking.

[0058] In summary, the present application proposes a Ka-band GEO satellite ground station antenna monopulse tracking control method, solves the communication interruption problem caused by the antenna pointing deviating from the satellite beam due to the cross-coupling index deterioration, and has the advantages of being simple and practical, easy to implement and strong in universality.

[0059] Finally, it should be noted that: the above only describes the preferred embodiments of the present application, and does not limit the present application, any modification, equivalent replacement, improvement, etc. made without departing from the spirit and scope of the present application defined by the appended claims should be included in the protection scope of the present application.

Claims

1. A Ka-band GEO satellite ground station antenna mono-pulse tracking control method, characterized in that, The method comprises the following steps: Step 1, the antenna servo device connects the single pulse tracking receiver, aligns the satellite to complete phase calibration, and obtains the directional sensitivity parameter s of the single pulse tracking system; Step 2, the antenna servo device calculates and sets the judgment threshold of tracking control according to the antenna aperture and the tracking frequency point; Step 3, the antenna servo device respectively establishes a length-n azimuth error array, a length-n elevation error array and a length-n total error array, adopts the sequential storage mode, respectively stores the azimuth error voltage Ua, the elevation error voltage Ue transmitted by the single pulse tracking receiver and the total error voltage U calculated by the antenna servo device, and n is an integer not less than 20; Step 4, start the single pulse tracking; Step 5, the antenna servo device collects the azimuth error voltage and the elevation error voltage transmitted by the single pulse tracking receiver in real time, moves the data in the three arrays one position at a time, and discards the overflow data, fills the currently collected azimuth error voltage Ua into the last position of the azimuth error array, fills the elevation error voltage Ue into the last position of the elevation error array, and calculates the total error voltage U according to U = Ua + Ue, and fills the total error voltage U into the last position of the total error array. Step 6, the antenna servo device calculates the azimuth error voltage and the elevation error voltage according to the following formulas, and transmits the calculated azimuth error voltage and the elevation error voltage to the antenna servo motor. Ua = Ua - Ua * K Ue = Ue - Ue * K Step 7, the antenna servo motor drives the antenna to rotate according to the azimuth error voltage and the elevation error voltage transmitted by the antenna servo device. Step 6, calculate the average value of the total error array to obtain the evaluation error V: ； Wherein, i is the data index in the total error array; Step 7, according to the evaluation error V and the judgment threshold, the single pulse tracking control is performed.

2. The method according to claim 1, wherein, The judgment threshold is divided into an alarm threshold T1 and a tracking threshold T2, the alarm threshold T1 is twenty one times of the antenna beam width multiplied by the directional sensitivity parameter s, that is: ； The tracking threshold T2 is ten times of the beam width multiplied by the directional sensitivity parameter s, that is: ； Wherein, s is the directional sensitivity, the unit is v / °; F is the tracking frequency point, the unit is GHz; D is the antenna aperture, the unit is m.

3. The method of claim 2, wherein the Ka-band GEO satellite ground station antenna monopulse tracking control method is characterized by, The specific way of step 7 is: If the evaluation error V is less than the alarm threshold T1, the antenna continues to perform the single pulse tracking; If the evaluation error V is greater than the alarm threshold T1 and less than the tracking threshold T2, the antenna continues to perform the single pulse tracking, and the antenna servo device prompts the cross coupling alarm; If the evaluation error V is greater than the tracking threshold T2, the antenna stops the single pulse tracking, and according to the antenna servo device configuration, one of the tracking modes of step tracking, memory tracking or program tracking is entered.

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