W. van der Wal
17 records found
1
Two-layer gravity inversion on Mars
Three different inversion methods to obtain a global density model of the crust and upper mantle of Mars
The origin of the Martian dichotomy is subject to question and no substantial evidence exists. Some surface and interior features that are not visible in, e.g., topography data, can show up in gravity data. Therefore, this research inverts gravity data to find a crustal and mantl
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Analyzing the Impact of Earth-Sun Distance Variations on Global Temperature
A Comparison of Simplified Solar System Models
This thesis investigates how variations in the Earth-Sun distance influence global temperatures, by comparing a simplified model of the solar system with an existing paper from V.V. Zharkova, claiming that increasing temperatures can be explained naturally. Over a 5000-year perio
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Over the past decade, there have been significant advancements in both the availability and diversity of satellite navigation systems, on both regional and global scales. The growing significance of GNSS across various fields has led not only to the modernisation of existing syst
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Collision Probability through Orbital Uncertainty Propagation
The Hybrid Differential Algebra and Gaussian Mixture Model Approach
The number of space objects has largely increased in the recent years, becoming a considerable threat to the present and future of satellite operations and human spaceflight. This introduces a need to accurately compute the risk of collision between satellites and space debris. C
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Transfer of Polarized Light in Extended Atmospheres
Applied to Exoplanets and Titan
We have developed, from scratch, a 3D radiative transfer code based on the Monte Carlo method, that fully takes into account the spherical shape of a planetary atmosphere, multiple scattering, and the polarized nature of light. Accounting for the sphericity of an atmosphere is im
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The first close-up image of a black hole has been taken recently by means of a network of high-resolution telescopes situated all around the globe, also known as Event Horizon Telescope (EHT). In that regard, this Master Thesis reviews the feasibility of establishing accurate int
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Extending Attitude Estimation Capability for Agile Precision Target Tracking NanoSats
Hardware Characterisation, Configuration Selection, and Gyro-Stellar based Unscented Calibration Filter Synthesis
Though NanoSats are becoming increasingly capable of featuring active payloads, and acquiring inertial data at arcsec level precision; the payload operational duty-cycle largely remains limited by its data downlink capabilities. NanoSat laser communication terminal (LCT) promises
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Examining the deformation in the Krafla region, Iceland
To get an insight on the recent changes in the observed deformation pattern
In the Krafla region in North East Iceland, a change in the deformation pattern was observed in 2018. Since the 1975-1984 rifting event, there was subsidence seen in the Krafla caldera and along the fissure swarm. This subsidence was explained by deflation which decreased exponen
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Saturn’s moon Enceladus harbours a global subsurface ocean beneath its icy crust. Tidal dissipation within the moon’s core generates a substantial amount of heat which leads to ocean convection. Observations of the moon indicate ocean thickness variations of up to 20 km from equa
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The objective of this master thesis research project is to determine the overall polarisation sensitivity of the Near Infrared Spectograph (NIRSpec) on board the JamesWebb Space Telescope (JWST). Understanding the polarisation sensitivity is important to correctly interpret the o
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Ganymede: A Frozen Enigma
Exploring possible internal density distributions through gravitational potential field variations
In 2022, ESA plans to launch the JUICE (JUpiter ICy moons Explorer) mission which will spend at least three years making detailed observations of Jupiter and three of its largest moons, Ganymede, Callisto and Europa. These moons are currently a hot topic within the science commun
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Large Low Shear-Velocity Provinces (LLSVPs) in Earth have been recognized in seismic data for several decades. The anomalies are however still poorly understood for reasons including their inconvenient location in the deep mantle, inhibiting progress in our understanding. Compreh
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The gravity field changes associated with the earthquake are analysed using the GRACE (Gravity Recovery and Climate Experiment) data. GRACE data can track the temporal variations in the gravity field and therefore information on mass redistribution can be achieved. There have bee
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Autonomous Guidance and Control for Precision Landing on Planetary Bodies
Convex Optimization Approach For Mars and Titan Case Studies
Autonomously landing a spacecraft on the surface of a planetary body with a degree of precision in the order of meters is highly challenging. Over the course of time, the landing ellipse, defined as the region with a 99% likelihood of where a space vehicle will land, has improved
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The Rotation and Interior Structure Experiment (RISE) on the InSight lander and the LaRa experiment on the ExoMars platform will provide precise measurements (accuracies of a few mas) of the rotation of Mars, in terms of the Mars rotation and orientation parameters (MOP). These p
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Development of a numerical model for the Sumatra subduction zone constrained by satellite gravimetry
With special focus on gravity sensitivity studies
Satellite-derived gravity models have been used in modelling of several subduction zones, but not yet for the Sumatra subduction zone. There, gravity models can shed light on the geometry and density of the plate, and whether a slab tear is present under northern Sumatra, as seis
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In this work interval analysis is applied to the thirteen control effector Innovative Control Effectors model to find its trim set. The method to find trim states is based on interval box consistency. At low speed the method is capable of finding interval enclosures of single tri
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