CN1115504A - satellite tracking method - Google Patents

Abstract

A satellite tracking method features that the full search mode is used to control the disk antenna to move up and down and left and right, the 4-division method is used to divide the search range into 4 equal parts, the signal strength of each point is detected, when the signal at a certain point is greater than a certain value, the 4-division method is used to divide the strongest signal into 4 equal parts to find the strongest signal until the last point, indicating that there is a satellite, and the signal strength measured by strength meter is used as the calculation reference for tracking device to regulate the vertical elevation angle and horizontal angle of disk antenna, so synchronizing the drift between disk antenna and drift satellite.

Description

satellite tracking method

The invention relates to a satellite tracking technology.

The background of the present invention is mainly: the satellite is originally fixed on the orbit of the equator. The orbit moves in a figure-eight manner, and the shape of the figure-eight will vary according to the region (refer to Figure 1), and the satellites will be at different points in the figure-eight due to different times. The dish antenna must move in a figure-of-eight pattern with the satellite at the same time to align with the drifting satellite and get a clear and complete picture.

The traditional automatic satellite tracking methods use the AGC voltage of the tuner to determine whether there is a satellite and determine the size of the satellite transmission signal. First, the tuner is set to demodulate a certain frequency channel, and then tune The AGC voltage output of the tuner indicates the signal strength of the channel, which is used to determine the alignment between the dish antenna and the satellite. However, because the signal size of each channel is variable, and even the channel setting control of the tuner is incorrect, Therefore, the dish antenna may not be aligned with the satellite, and sometimes the dish antenna is already aligned with the satellite, but when the channel set by the tuner is incorrect or there is no program on the channel, the output shows that it is not aligned with the satellite. The disadvantages can be summarized as follows:

1. Although the dish antenna is aimed at the satellite, if the demodulation frequency of the tuner is set to a channel with no programs, it will be considered that there is no satellite.

2. Although the satellite is the same, the signal size of each channel is often different, so it is not objective to take a certain channel as the basis for the signal size of satellite tracking and alignment.

3. The AGC voltage output of the tuner mostly only indicates whether the signal is good or bad, and most of the difference between good and bad is only within 6dB. If the signal strength is -35dB under a good signal, the signal strength is not At -50dB, the AGC voltage output of the tuner is the same from -35dB to -44dB, so it cannot be used as the best alignment between the dish antenna and the satellite.

4. Since the tuner is already in the satellite receiver (RECEIVER), the AGC change of the tuner used by each manufacturer is different, and the AGC change of the tuner is also different for different satellites and different weather environments; If the user directly judges the satellite tracking method based on the size of the AGC signal, it will cause great trouble to the user. When the satellite signal changes, most users will not adjust the size of the AGC signal. Professionals must be used. For consumers, it is time-consuming and expensive.

The object of the present invention is to propose a satellite tracking method for the above shortcomings, so that the process of tracking satellites has good accuracy, objectivity and automaticity, and the viewer will not feel the inconvenience of satellite drift.

The main content of the satellite tracking method of the present invention is: use the full search method to control the dish antenna to move up and down and left and right, and use the 4-point method to divide the search range into 4 equal parts, detect the signal strength of each point, and when the signal of a certain point When the strength is greater than a certain value, use the 4-point method to divide the strongest signal into 4 equal parts to find the strongest signal until the last point, which means that there is a satellite here; then use the signal strength measured by the strength meter in the tracking device As a calculation basis, the tracking device adjusts the degrees of rotation of the horizontal motor and the vertical motor according to the input data.

In order to have a further understanding of the method of the present invention, now in conjunction with the following drawings in detail as follows:

Description of drawings:

Fig. 1 is the drift status diagram of the satellite;

Fig. 2 is a schematic diagram of a satellite tracking method;

Fig. 3 is satellite tracking mode (full search Full search) figure of the present invention;

Fig. 4 is fast search (Fast search) figure;

Fig. 5 is a system block diagram of the present invention;

Fig. 6 is a spectrum diagram of a satellite signal of the embodiment.

Above-mentioned technical scheme is as follows:

1. Design concept:

The satellite tracking method of the present invention adopts the tracking device as a locator, directly uses the signal of the down-converter (LNB), and uses the magnitude of the signal as the basis for tracking.

2. Design method:

The current satellite TV programs can be roughly divided into two frequency bands, C-band and Ku-band. The transmission frequency band of the satellite in C-band is 3.7GHz～4.2GHz, while the transmission frequency band of Ku-band is 10.9GHz～12.75GHz. The signal of C-band or Ku-badn is 950MHz~2050MHz after passing through LNB, as shown in Figure 2, there are 6 channels in 950MHz~2050MHz. , at this time, the detector will take out the strongest signal in the six channels (channel 5) and convert its signal strength into a voltage value. Since there are still some AC fluctuations in this voltage value, it will be filtered through the following And amplify the line, and then output the voltage to the CPU as a benchmark for signal strength comparison (refer to Figure 2).

3. The use status of the locator system

(1) Set-up: Using the concept of full search, as shown in Figure 3, it is a satellite tracking locator, which controls the dish antenna to move up and down and left and right, and detects the signal strength of each point. When the signal at a certain point is greater than a certain default value, it means that there are satellites here, so it is quite simple to set up (Set-up), and there is no need to use other expensive instruments and equipment.

(2) In use: When the user is already using the satellite, the satellite tracking method is to shift a little bit above, below, left and right every once in a while, to find the point with the strongest signal strength, and put the The dish antenna is moved to the strongest signal, and it will be tracked in the same way in the future. Since the locator moves automatically during the tracking process, and the offset of the dish antenna is small each time, the user will not watch the program. There is a feeling of good and bad signals, and what you see is the best.

(3) When changing satellites to watch, the locator will move the dish antenna to the position according to the position of the satellite when it is set (Set-up), and find the point with the strongest signal within a certain range there, and stop Here, the search method emphasizes fast search (Fast search), so using the 4-point method, first divide this range into 4 equal parts, find out the strongest signal of a certain part, and then use the strongest part of the signal Divide into 4 equal parts, then compare the signal strength, and then repeat the same action until the last point (refer to Figure 4).

The satellite tracking mode of the present invention is as follows:

1. Use the concept of full search and fast search (full Search, Fast Search) to make the satellite tracking and positioning device control the dish antenna to move up and down and move left and right, and detect the signal strength of each point, and set it to the maximum signal point. Tracked satellite signals.

2. The present invention measures the signal transmitted by the satellite through the signal strength meter, and obtains the strongest signal, and inputs it to the CPU as the basis for the moving angle of the dish antenna.

Fig. 5 shows satellite tracking device and method of the present invention:

The dish antenna 2 is equipped with a down-converter 3 and an optical coupling device 4. The optical coupling device 4 will send a horizontal pulse signal 41 and a vertical pulse 42 due to the action of the horizontal and vertical motors for analysis and calculation by the CPU 54, and a cable Connect the signal strength meter 51 of the dish antenna 2 and the satellite tracking device 5, measure its signal strength by the signal strength meter 51, then through the comparator 53, and the value converted by the digital-to-analog converter 55 with a signal output by the CPU 54 inside For comparison, the result is sent to the CPU 54, and the CPU 54 collects external data and then calculates the horizontal displacement output value and the vertical displacement output value and sends them to the drivers 56 and 57 to control the rotation degrees of the horizontal motor 6 and the rotation degree of the vertical motor 7 respectively. Align the dish antenna 2 with the position of the satellite 1.

When setting (Set-up), the left and right limits of the horizontal direction and the upper and lower limits of the vertical direction will be set first. With the help of the horizontal pulse signal 41 and the vertical pulse signal 42, the CPU will know the vertical and horizontal limits after calculation. position, and the horizontal and vertical motors 6 and 7 can adjust the rotation angle of the dish antenna.

Figure 6 shows the spectrum diagram of the satellite tracking signal. The figure shows that the satellite 1 antenna transmits a total of six channels, and the signal of the mid-frequency band (950MHz～2050MHz) is obtained by the down-converter (LNB) 3, and the frequency of each channel is divided Different outside, its signal strength is also different, the present invention is the channel with the strongest alignment signal, the 5th channel as shown in Figure 6, so the signal strength meter 51 can select the 5th channel signal, send to comparator 53 and To CPU 54, therefore the size of the No. 5 channel signal received determines the alignment of dish antenna 2 and satellite 1, impels dish antenna 2 to move with satellite 1 moving direction.

Looking at the description and description of the above-mentioned related structures, it can be seen that the satellite tracking method of the present invention has the following advantages:

1. The present invention tracks satellites with full search and fast search (Full-Search) and (Fast Search) (four-point method). During the tracking process, fast is emphasized, and the existence of satellites will not be lost.

2. The signal strength meter is used in the locator, so it provides good objectivity and practicability for the alignment between the satellite and the dish antenna.

Claims (2)

1. A satellite tracking method, which is a full search (Full Serach) method, controls the dish antenna to move up and down and left and right, and uses the 4-point method to divide the search range into 4 equal parts, and detects the signal strength of each point. When a certain When the signal at the point is greater than a certain value, use the 4th method to divide the strongest signal into 4 equal parts to find the strongest signal until the last point, indicating that there is a satellite here. 2. The satellite tracking method according to claim 1, wherein the signal strength measured by the signal strength meter is used as a calculation basis for the tracking device, so that the tracker adjusts the degrees of rotation of the horizontal motor and the vertical motor according to the input data.

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