CN-120128239-B - Star searching system and method for ground terminal

CN120128239BCN 120128239 BCN120128239 BCN 120128239BCN-120128239-B

Abstract

The application relates to the technical field of satellite communication and discloses a satellite searching system and a satellite searching method of a ground terminal, wherein the system comprises a main device, a satellite searching device and a satellite searching device, wherein the main device is provided with a first antenna and a second antenna, the first antenna is used for communicating with a slave device, and the second antenna is used for receiving a low-orbit satellite beacon signal; the system comprises a slave device, a synchronization module and a master device calculation module, wherein the slave device is provided with a first antenna and a second antenna, the first antenna is used for communicating with the master device, the second antenna is used for receiving a beacon signal of a satellite, the synchronization module is used for synchronizing the master device with a clock of the slave device, and the master device calculation module is used for calculating the position of the satellite in a coordinate system of the master device in combination with the position of the slave device. According to the application, the intercommunication between the master device and the slave device is realized through the first antenna, and the master device calculates the accurate position of the satellite according to the time difference and the position by utilizing the timestamp data of the slave device, so that the positioning problem when ephemeris information is lost or can not be updated in real time is solved.

Inventors

LIU SHAODONG
ZHU JIAO
LIN YESONG

Assignees

上海京济通信技术有限公司

Dates

Publication Date: 20260508
Application Date: 20250310
Priority Date: 20250228

Claims (7)

1. A satellite searching system for a ground terminal, comprising: A master device having a first antenna for communicating with a slave device and a second antenna for receiving low-orbit satellite beacon signals; A slave device having a first antenna for communicating with the master device and a second antenna for receiving a satellite beacon signal and transmitting the satellite beacon signal to the master device through the first antenna; A synchronization module for synchronizing clocks of the master device and the slave device; the master device calculation module is used for calculating the position of the satellite in a master device coordinate system based on the time difference of the satellite beacon signals received by the synchronized slave device and combining the position of the slave device; the synchronization module comprises a Kalman filtering algorithm unit and is used for estimating and optimizing clock synchronization errors between the master equipment and the slave equipment; the slave devices are provided with a plurality of slave devices, the slave devices are in communication connection with the master device and then perform clock synchronization, and the time synchronization uses a Kalman filtering algorithm: ; Wherein, the Is Kalman gain; the covariance matrix of the estimation error at the previous moment is used for representing the degree of the estimation error at the previous moment; is an observation matrix; The noise covariance matrix is used for observing, and the noise size and uncertainty in the observation process are represented; is the transpose of the observation matrix.
2. A satellite search system for a ground terminal according to claim 1, wherein said master device further comprises a signal processing module for preprocessing satellite beacon signals transmitted from the slave device and transmitting to the master device calculation module, said preprocessing comprising: the denoising unit is used for removing environmental noise in the received satellite beacon signals; and the enhancement unit is used for carrying out signal enhancement on the received satellite beacon signals.
3. A satellite search system for a ground terminal according to claim 1, further comprising an antenna beam pointing module for adjusting the second antenna pointing of the master and slave devices according to the position of the satellite in the master device coordinate system.
4. A satellite searching method for a ground terminal based on a satellite searching system for a ground terminal according to any of claims 1-3, comprising the steps of: arranging a master device and a slave device, and connecting the master device and the slave device in a communication way; receiving a beacon signal of a satellite by using the slave device, recording the signal receiving time, and transmitting the signal receiving time to the master device; The master device obtains a time difference of receiving the satellite beacon signal by the slave device based on the satellite beacon signal and the signal receiving time, and calculates the position of the satellite in the coordinate system of the master device by combining the position of the slave device.
5. The method for searching for satellites in the ground terminal according to claim 4, wherein a plurality of slave devices are provided, and clock synchronization is performed after the plurality of slave devices are in communication connection with the master device, and a kalman filter algorithm is used for the time synchronization: ; Wherein, the Is Kalman gain; the covariance matrix of the estimation error at the previous moment is used for representing the degree of the estimation error at the previous moment; is an observation matrix; The noise covariance matrix is used for observing, and the noise size and uncertainty in the observation process are represented; is the transpose of the observation matrix.
6. The method for searching for satellites in a ground terminal according to claim 4 wherein the calculating the position of the satellites in the coordinate system of the main device is performed by using a least square algorithm, the formula of the least square algorithm comprising: ; Wherein, the The satellite position calculated by the main equipment; n is the number of devices participating in calculation and represents the number of signal data; Is the location of the ith slave device; Is the distance from device i to the satellite; is the estimated distance from device i to the satellite.
7. The method for searching for satellites in a ground terminal according to claim 4 wherein the relative angles between the main device antenna and the slave device antenna and the satellite are adjusted according to the position of the satellite in the main device coordinate system after the position of the satellite in the main device coordinate system is known.

Description

Star searching system and method for ground terminal Technical Field The invention relates to the technical field of satellite communication, in particular to a satellite searching system and method of a ground terminal. Background In modern satellite communication systems, accurate satellite position data is required for communication between ground terminals and satellites. Typically, satellite positions are obtained from ephemeris data (e.g., TLE data or real-time ephemeris data) which provides orbital information about the satellites so that the ground terminals can calculate the precise position of the satellites and transmit and receive signals based thereon. However, obtaining accurate ephemeris data may be limited in some situations, especially where real-time ephemeris data is not available or where satellite orbit information cannot be updated in real-time. In this context, conventional satellite positioning systems may suffer from problems such as communication interruption, ephemeris information loss or delayed update, resulting in a ground terminal not being able to accurately acquire the position of the satellite. Disclosure of Invention Aiming at the defects of the prior art, the invention provides a satellite searching system and a satellite searching method for a ground terminal, which solve the problem that the ground terminal cannot accurately acquire the satellite position under the condition that real-time ephemeris data cannot be acquired or satellite orbit information cannot be updated in time. In order to achieve the purpose, the invention is realized by the following technical scheme that the satellite searching system of the ground terminal comprises: A master device having a first antenna for communicating with a slave device and a second antenna for receiving low-orbit satellite beacon signals; A slave device having a first antenna for communicating with the master device and a second antenna for receiving a satellite beacon signal and transmitting the satellite beacon signal to the master device through the first antenna; A synchronization module for synchronizing clocks of the master device and the slave device; the master device calculation module calculates the position of the satellite in the master device coordinate system according to the position of the slave device based on the time difference of the satellite beacon signals received by the synchronized slave device. Preferably, the synchronization module comprises a kalman filter algorithm unit for estimating and optimizing clock synchronization errors between the master device and the slave device. Preferably, the master device further includes a signal processing module, configured to pre-process the satellite beacon signal transmitted from the slave device and transmit the pre-processed signal to the master device computing module, where the pre-processing includes: the denoising unit is used for removing environmental noise in the received satellite beacon signals; and the enhancement unit is used for carrying out signal enhancement on the received satellite beacon signals. Preferably, the system further comprises an antenna beam pointing module for adjusting the second antenna pointing of the master and slave devices according to the position of the satellite in the master device coordinate system. A satellite searching method of a ground terminal comprises the following steps: arranging a master device and a slave device, and connecting the master device and the slave device in a communication way; receiving a beacon signal of a satellite by using the slave device, recording the signal receiving time, and transmitting the signal receiving time to the master device; The master calculates the position of the satellite in the master coordinate system based on the beacon signal and the signal reception time of the satellite. Preferably, the slave devices are provided with a plurality of slave devices, and the slave devices and the master device are in communication connection and then perform clock synchronization, and the time synchronization uses a kalman filtering algorithm: Wherein K k is Kalman gain, P k-1 is an estimated error covariance matrix of the last moment and represents the degree of estimated error of the last moment, H k is an observation matrix, R k is an observation noise covariance matrix and represents the noise size and uncertainty in the observation process; is the transpose of the observation matrix. Preferably, the calculating the position of the satellite in the main device coordinate system is calculated by using a least square method, and a formula of the least square method includes: Wherein, the Is the satellite position calculated by the master device, x satellite represents the satellite position vector in three-dimensional space, which is the target to be solved, N is the number of devices involved in the calculation, x i is the i-th slave device's position, d i is the distance from d