Geostationary Satellite Positioning Using Multi-Station Correlation
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Solution Overview
Problem
Current methods for high-precision ranging of geostationary artificial satellites require expensive large-diameter antennas and occupy transponder bands, making them impractical for efficient orbit control.
Innovation Solution
A system using two or more antennas to measure the difference in reception times of signals from a geostationary satellite, allowing for distance calculation without a dedicated reference signal, using commercial antennas and eliminating the need for uplink equipment, enabling precise three-dimensional orbit determination.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If one-station ranging with a single ground station is used, then the equipment cost is reduced, but the measurement precision deteriorates due to large distance causing significant angle errors
Solution Approach 1:
The invention transitions from two-dimensional angle measurement at a single station to three-dimensional spatial positioning by introducing multiple ground stations. The position is determined by combining distance measurements from multiple stations with the known baseline distances between stations, converting a 2D angle-based problem into a 3D spatial problem that eliminates angle error sensitivity.
Solution Approach 2:
The invention introduces baseline distance measurements between ground stations as an intermediary parameter. Instead of directly measuring the difficult-to-obtain precise angle at a single station, the system measures the baseline distance between stations and uses this as a mediator to calculate the satellite position through triangulation, thereby avoiding the angle error problem.
2Measurement precision
If multiple ground stations are used for ranging, then the measurement precision is improved, but the device complexity increases due to need for multiple reception stations and synchronization equipment
Solution Approach 1:
The invention makes each ground station multi-functional by equipping them with both reception capabilities for satellite signals and transmission capabilities for baseline measurement signals. Each station serves as both a receiver for positioning data and a transmitter for synchronization, reducing the need for separate dedicated equipment and simplifying the overall system architecture.
Solution Approach 2:
The invention merges the functions of satellite signal reception and baseline measurement into a unified system. The same ground stations used for receiving satellite positioning signals are also used for measuring baseline distances through signal transmission, combining multiple functions into single equipment sets and reducing overall system complexity.
3Measurement precision
If a dedicated reference signal is transmitted to the satellite for ranging, then the measurement precision is improved, but the loss of substance increases due to occupation of transponder band that could be used for service
Solution Approach 1:
The invention enables ground stations to perform self-measurement of baseline distances by transmitting signals and measuring the round-trip time or phase difference. The system uses its own existing equipment and signals to determine baseline distances without requiring external reference signals from the satellite, making the ranging process self-sufficient and eliminating transponder band occupation.
Solution Approach 2:
Instead of transmitting reference signals from the satellite down to ground stations (traditional active ranging), the invention inverts the direction by having ground stations transmit signals to each other to measure baselines. This passive ranging approach uses ground-based measurements rather than satellite-based signal transmission, freeing up the transponder band for service use.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach reduces equipment costs and eliminates transponder band usage, achieving high-precision ranging with simpler equipment, suitable for geostationary satellite orbit control, particularly beneficial for countries with limited land area.
Implementation Method 1
correlation processing means for calculating a difference in reception time of a same signal between the first antenna and the second antenna, by performing correlation processing on the reception signal of the first antenna and the reception signal of the second antenna
Implementation Method 2
measurement means for measuring a distance between the first antenna and the geostationary artificial satellite on the basis of the measurement result of the round-trip time of a signal between said first antenna or an antenna for measurement disposed close to said first antenna and said geostationary artificial satellite
Data Source
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AI summary
Ground stations 20, 21 receive any signal transmitted by a geostationary artificial satellite 10, and store the reception signal together with the reception time thereof. A difference Δt in reception time of a same signal between the ground station 20 and the ground station 21 is calculated by performing correlation processing of the reception signal of the ground station 20 and the reception signal of the ground station 21. A distance R20 between the ground station 20 and the geostationary artificial satellite 10 is measured by a distance measurement device. A distance R21 between the ground station 21 and the geostationary artificial satellite 10 is calculated on the basis of the distance R20 obtained by measurement and the difference Δt in reception times, as obtained by correlation processing.