Capturing and tracking system based on relay terminal and on-orbit phase calibration method

Abstract

The invention discloses a capturing and tracking system based on a relay terminal and an on-orbit phase calibration method. The system comprises a Ka relay antenna, a directional coupler module, a first filter module, a second filter module, a first low noise amplifier module, a second low noise amplifier module, a single-channel modulation module, a Ka/C frequency conversion module, a capturing and tracking module and a servo control module. The on-orbit phase calibration method includes the steps that by means of the curve characteristics that pitching and orientation are orthogonal and the phase of the pitching is 90 degrees ahead of orientation, when the single-channel modulation module and a channel N-place phase shifter change in a linear progressive increase mode from 0 degree to 360 degrees, the relative phase error of a sum channel and a difference channel is calculated, and automatic on-orbit angle compensation is carried out. Compared with the method that a ground calibration and correction tower is adopted for phase calibration and a fixed phase value is set in the prior satellite technology, the on-orbit phase calibration method guarantees angle compensation correctness, improves phase calibration simplicity, real-time performance and repeatability and reduces error cross coupling terms brought by phase differences.

Description

technical field [0001] The invention relates to an acquisition and tracking system based on a relay terminal and an on-orbit phase calibration method, which are mainly used in various low-orbit spacecraft relay acquisition and tracking systems, and belong to the technical field of satellite radio tracking and measurement. Background technique [0002] The Σ and Δ signals formed by the target signal entering the antenna pass through a long channel respectively. When reaching the single-channel modulator, the phase relationship between Σ and Δ often changes over time due to changes in various factors such as temperature and circuit parameters. That is, it is not possible to maintain the adjusted phase relationship all the time. [0003] This relative phase change of the sum and difference will cause the azimuth and pitch error characteristics to deteriorate, such as the slope of the error characteristic curve becomes smaller, the polarity of the error characteristic changes, a...

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Problems solved by technology

[0007] 1) The phase calibration process is complicated: the satellite-ground system equipment participates in the calibration, or establishes a ground calibration tower for phase calibration. The calibration process involves many equipment, high cost, and complex system

[0008] 2) The accuracy of phase calibration is not high: the higher bits of the phase shifter are used for phase adjustment to achieve the phase consistency of the sum signal Σ and the difference signal Δ, the phase calibration accuracy is low, and the residual part of the cross-coupling term

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