Spacecraft Navigation Using Pulsar Signal Timing
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Solution Overview
Problem
Current navigation systems for spacecraft face challenges in accurately determining position, velocity, and attitude, especially at greater distances from Earth, due to errors in radar and optical tracking methods, and limitations of celestial source-based navigation systems like pulsar navigation, which suffer from low signal intensity and interference from other celestial objects.
Innovation Solution
A system and method utilizing modulated celestial radiation, such as pulsed radiation from pulsars, to calculate navigational data by detecting the time of arrival of radiation signals and using a timing model to estimate the state of modulation characteristics, allowing for determination of navigational parameters relative to a reference point, and incorporating relativistic effects for accurate positioning.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If ground-based radar and optical tracking are used to determine spacecraft position, then position information can be obtained, but errors increase with distance from Earth and extensive ground tracking is required
Solution Approach 1:
The invention extracts the navigation reference from Earth-based systems and relocates it to celestial sources. By using pulsars and other celestial objects as navigation beacons, the system removes the dependency on extensive ground tracking infrastructure while maintaining position determination capability through signal reception at the spacecraft itself
Solution Approach 2:
The invention introduces celestial radiation sources, particularly pulsars, as intermediary reference points between the spacecraft and the navigation system. These celestial bodies emit stable electromagnetic signals that serve as natural beacons, allowing the spacecraft to determine its position relative to the solar system barycenter without direct Earth-based tracking
2Measurement precision
If Earth-based observation stations are used for navigation, then position can be determined, but the system requires precise knowledge of station locations and labor-intensive human control
Solution Approach 1:
The invention enables the spacecraft to perform its own navigation autonomously by receiving and processing celestial signals onboard. The system uses on-board clocks to measure signal arrival times and onboard processors to calculate position, velocity, and attitude, eliminating the need for labor-intensive human-controlled ground tracking operations
Solution Approach 2:
The invention replaces the mechanical and human-operated ground tracking system with an automated electronic system that uses natural celestial radio sources. The navigation function transitions from active Earth-based measurement to passive reception of celestial signals processed autonomously by the spacecraft
3Length of moving object
If distance from Earth increases, then spacecraft can reach farther destinations, but range and transverse axis measurement errors increase
Solution Approach 1:
The invention creates a universal navigation system that functions throughout the solar system by using distant celestial sources as references. Since pulsars and other celestial objects are effectively at infinite distance, they provide stable reference signals that work equally well for near-Earth and interplanetary navigation, making the system universally applicable regardless of distance from Earth
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 enables precise determination of a spacecraft's position, velocity, and attitude with reduced errors, even at great distances, by leveraging stable and unique signals from celestial sources, improving navigation autonomy and accuracy without requiring extensive ground-based infrastructure.
Implementation Method 1
a mobile receiver for detecting signals generated by celestial sources of modulated radiation
Data Source
AI summary
A system and method for navigation utilizes sources of modulated celestial radiation. A spacecraft, satellite, or other vehicle (12) includes one or more modulated radiation sensors (22a-22x) for detecting a modulated signal (14) generated by one or more pulsars or other celestial objects (16). Pulse time of arrival at a respective pulse sensor (22a-22x) is measured by comparing the pulse signal (14) with a known pulse profile. A processor (30) calculates a timing difference between the measured pulse time of arrival at sensor (22a-22x) with a calculated pulse time of arrival at a selected reference point (100). Positions and pulse profile characteristics of the pulsars (16) are stored. Combining the calculated time difference with the known positions of pulsars (16), navigational parameters such as position, velocity, and attitude for spacecraft (12) with respect to the selected localized reference point (100) can be calculated.