Optimization of Repeat Ground Track Constellation Design for Complex Discontinuous Regional Coverage
Available at: https://digitalcommons.calpoly.edu/theses/3281
Date of Award
6-2026
Degree Name
MS in Aerospace Engineering
Department/Program
Aerospace Engineering
College
College of Engineering
Advisor
Madhusudan Vijayakumar
Advisor Department
Aerospace Engineering
Advisor College
College of Engineering
Abstract
The continued growth of low Earth orbit (LEO) satellite constellations motivates efficient constellation design methods to reduce cost and complexity. Although brute-force methods are commonly employed in the preliminary design of satellite constellations, pairing analytic methods with optimization algorithms provides a more efficient means of searching the design space. Constellation design for continuous global and regional coverage is well-established; however, strategies for discontinuous regional coverage remain underdeveloped. This thesis focuses on an analytic geometry-based method for computing satellite coverage and revisit metrics, coupled with genetic algorithm optimization to efficiently explore the design space. The viability of this method is shown through four unique case studies, applied to varying regional coverage problems. Each case study examines a relevant subset of constellation design metrics, including coverage time, guaranteed coverage area, possible coverage area, maximum revisit gap, and number of satellites. Both continuous and discontinuous coverage regions are examined across the case studies, one of which includes a subregion of increased viewing interest. A novel geometry-based approach computes a lower bound on the achievable and guaranteed coverage area for a repeat ground track satellite constellation. These approaches eliminate the computational overhead inherent to numerical propagation and the discrete-time-step evaluation of coverage and revisit metrics. The geometry-based coverage approach accounts for the spacecraft orbit, sensor characteristics, and region of interest using propagation-free repeat ground track geometry with first-order secular J2 corrections. The presented methods apply to complex continuous and discontinuous regions. The case studies in this thesis utilize Walker-Delta and Walker-Delta type constellations which permit variable interplane spacing. The key application of this work lies in preliminary mission design, where the improvement of computational speed to accelerate search space exploration is paramount.