Method for calibrating delay inconsistency of radio star signal and spacecraft signal in interferometry

Abstract

The invention discloses a method for calibrating delay inconsistency of a radio star signal and a spacecraft signal in interferometry. Very long baseline interferometry is to use a plurality of observation stations in different geographic positions to receive a signal from a same target in the space to be processed, time delay difference from the target to two observation stations with definite positions is calculated by utilizing relevant phase and observation frequency (or bandwidth), and calibration by utilizing a radio star is a main way for eliminating common error in the very long baseline interferometry. Therefore, in interferometry, the radio star signal and the spacecraft signal are transmitted through an identical route so as to guarantee the calibration accuracy. However, because of the reasons that the characteristics of the radio star signal and the spacecraft signal are different and for improving the utilization rate of equipment and reducing the quantitative loss of the spacecraft signal, different processing ways are adopted by a system for the two signals in measurement rather than the traditional identical processing way by which the radio star signal and the spacecraft signal are transmitted through different equipment routes, and the time delay difference of the two routes needs to be precisely determined to guarantee the calibration accuracy.

Description

technical field

[0001] The invention is designed to be a calibration technique for inconsistent delays when radio star signals and spacecraft signals in the field of very long baseline interferometry (VLBI) are processed in different ways, and is especially suitable for interference reception of different signals in deep space interferometry. Background technique

[0002] When performing interferometric measurements, the VLBI standard requires that the baseband conversion and recording have the same sampling rate and quantization bits for each channel of the same signal. Because the radio star signal has a broad spectrum similar to a white noise signal, and the amplitude is weak; the spacecraft signal is generally a narrow-band signal, and the amplitude is strong. The bandwidth is narrow; parameters such as sampling rate and quantization bits used to collect the two signals are also different. VLBI observations were mainly applied to radio stars in the past, and exactly the...

Examples

Embodiment Construction

[0023] refer to figure 1 , a method for calibrating inconsistent time delays of radio star signals and spacecraft signals during interferometry, characterized in that it comprises the following steps:

[0024] ① When performing interferometric measurements, the antenna sends the radio star signal and spacecraft signal received simultaneously or in time division to the field amplifier through the coupler at the front end of the field amplifier; the calibration signal generation unit also sends the phase correction signal through the coupler of the field amplifier to the field release;

[0025] ②The field amplifier amplifies the input radio star signal, spacecraft signal and phase correction signal and outputs it to the down converter;

[0026] ③The down-converter down-converts the input amplified radio star signal, spacecraft signal and phase correction signal into intermediate frequency signals respectively, and outputs the frequency-converted radio star signal and phase corr...

technical field

[0001] The invention is designed to be a calibration technique for inconsistent delays when radio star signals and spacecraft signals in the field of very long baseline interferometry (VLBI) are processed in different ways, and is especially suitable for interference reception of different signals in deep space interferometry. Background technique

[0002] When performing interferometric measurements, the VLBI standard requires that the baseband conversion and recording have the same sampling rate and quantization bits for each channel of the same signal. Because the radio star signal has a broad spectrum similar to a white noise signal, and the amplitude is weak; the spacecraft signal is generally a narrow-band signal, and the amplitude is strong. The bandwidth is narrow; parameters such as sampling rate and quantization bits used to collect the two signals are also different. VLBI observations were mainly applied to radio stars in the past, and exactly the...

Examples

Embodiment Construction

[0023] refer to figure 1 , a method for calibrating inconsistent time delays of radio star signals and spacecraft signals during interferometry, characterized in that it comprises the following steps:

[0024] ① When performing interferometric measurements, the antenna sends the radio star signal and spacecraft signal received simultaneously or in time division to the field amplifier through the coupler at the front end of the field amplifier; the calibration signal generation unit also sends the phase correction signal through the coupler of the field amplifier to the field release;

[0025] ②The field amplifier amplifies the input radio star signal, spacecraft signal and phase correction signal and outputs it to the down converter;

[0026] ③The down-converter down-converts the input amplified radio star signal, spacecraft signal and phase correction signal into intermediate frequency signals respectively, and outputs the frequency-converted radio star signal and phase corr...

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