Absolute time delay calibration method for inter-satellite link of navigational satellite

Abstract

The invention provides an absolute time delay calibration method for an inter-satellite link of a navigational satellite. The inter-satellite link of the navigational satellite is provided with a plurality of antennas and uses transmission signals as spread spectrum ranging signals, so that an inter-satellite link transmitter transmits spread spectrum signals with the same structure with the inter-satellite link transmission signal through an antenna to be detected, and an inter-satellite link receiver is used for receiving the spread spectrum signals through one another antenna to be detected. Receiving-transmitting link combined time delays which are formed by matching three or more than three antennas in pair can be measured. An absolute time delay when each testing antenna receives and transmits inter-satellite link signals is obtained through data processing according to a combined time delay value, a zero calibration result of a testing channel, and a space transmission time delay of a receiving-transmitting antenna. The method provided by the invention is simple and convenient to operate without a special calibration antenna. By using a test signal with the same structure with the inter-satellite link transmission signals, the transmission time delay of the inter-satellite link signals can be actually reflected by a calibration result.

Description

technical field [0001] The invention relates to a method for calibrating the absolute time delay of an inter-satellite link antenna of a navigation satellite, which can be used for calibrating the absolute time delay of an inter-satellite link antenna of a navigation satellite system. Background technique [0002] In the global satellite navigation system, maintaining high satellite orbit determination accuracy and clock error determination accuracy is the key to ensure that the navigation receiving terminal obtains the positioning or timing accuracy required by the large system. Obtaining precise orbit and clock error parameters usually requires the deployment of a large number of ground stations around the world for continuous observation. At present, my country does not have such global strategic geographic resources. Therefore, the global satellite navigation system under research in my country will use inter-satellite link technology, among which An important function is...

AI Technical Summary

Problems solved by technology

Both the zero-spacing transponder and the zeroing antenna are used in the calibration tower method and the non-tower calibration method. The precise calibration of the absolute time delay of the zero-spacing transponder and the zeroing antenna itself is also a difficult test, and their calibration accuracy will seriously affect the antenna under test. The calibration accuracy of the delay, the use of the zero-spacing transponder is different from the actual working condition of the inter-satellite link antenna, the calibration result is different from the delay value under the real working state of the inter-satellite link antenna, and there is no tower calibration method In the above, different installation positions of the zeroing antenna will lead to changes in the calibration value, and the determination error of the installation position of the zeroing antenna will also cause calibration errors

The vector network analysis method uses a standard antenna as a test reference. For the ka-band antenna of the navigation satellite inter-satellite link, it is difficult to obtain a standard antenna for testing the delay. When testing with a road analyzer, the test connection cable or waveguide is long, and it is very difficult to ensure stable and high-precision delay calibration of long test cables or waveguides under the Ka-band working condition

The most important thing is: the delay value tested by the vector network analyzer is the group delay of a frequency band, which cannot correctly reflect the delay of the spread spectrum ranging signal of a specific signal system transmitted by the inter-satellite link

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