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Perturbed Visibility Problem for a Terrestrial and Lunar orbiter

Ramadhin, D H (2024) Perturbed Visibility Problem for a Terrestrial and Lunar orbiter.

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Abstract:This report aims to solve the satellite-to-site visibility problem using Escobal’s controlling equation, an analytically developed transcendental equation. Once or twice per orbital revolution, this equation is solved numerically to determine the rise and set eccentric anomalies, yielding the visibility windows during which communication between a satellite and ground station is possible. The satellite’s orbit, whether in low Earth or Lunar orbit, is first determined by the two-body problem and then refined by accounting for the dominant perturbations: nonspherical gravity and third-body attraction. These perturbations are averaged to eliminate short-period effects, and incorporated with the Lagrange. To verify the accuracy of the controlling equation, the visibility problem is also solved using the traditional brute force method. The required ephemeris is generated with Cowell’s method. The methodology and implementation is first validated with a Terrestrial orbiter, where the evolution of the orbital elements aligns well with documented. The approach is then extended to a Lunar orbiter, where the Moon’s gravitational field requires the inclusion of higher-degree harmonics for accurate modelling, as the second zonal harmonic is less prominent than for the Earth. Additionally, the proximity of Earth necessitates modelling its gravitational influence as a third-body perturbation.
Item Type:Essay (Master)
Clients:
Instituto Tecnológico de Aeronáutica, São José dos Campos, Brazil
Faculty:ET: Engineering Technology
Subject:39 astronomy, 52 mechanical engineering
Programme:Mechanical Engineering MSc (60439)
Link to this item:https://purl.utwente.nl/essays/104564
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