Pulsar Emissions, Signal Modeling and Passive ISAR Imaging

Area of Science:

• Radio astronomy
• Astrophysics
• Radar imaging

Background:

• Pulsar emissions, particularly from the Crab Nebula, exhibit high coherency due to plasma effective temperature.
• This coherency is crucial for practical applications in space object navigation, localization, and imaging.
• Inverse Synthetic Aperture Radar (ISAR) principles offer a framework for analyzing reflected signals.

Purpose of the Study:

• To model Crab Nebula pulsar emissions for asteroid detection and imaging.
• To apply inverse synthetic aperture radar (ISAR) principles to pulsar signals reflected from space objects.
• To develop and demonstrate a novel range compression approach for ISAR imaging.

Main Methods:

• Creation of a time-frequency grid mathematical model of pulsar emissions using Goldstone-Apple Valley and Arecibo radio telescope data.
• Description and graphical illustration of a passive ISAR scenario, space object geometry, and pulsar signal reflection models.
• Application of coherent summation of multiple complex images to reduce noise and enhance signal-to-noise ratio.

Main Results:

• A novel range compression method for ISAR imaging was developed and demonstrated.
• Numerical experiments validated the proposed geometry, signal models, and theoretical analysis.
• The study shows the potential for using pulsar emissions in space object imaging.

Conclusions:

• The developed mathematical model and ISAR approach are effective for analyzing pulsar emissions for space object applications.
• The proposed range compression technique improves ISAR image quality.
• This research provides a foundation for utilizing pulsar signals in advanced space surveillance and imaging systems.