Pages
- 1
- 2
- document
-
Coco Martin, C.M. (author), Hu, Weiya (author), Cavallo, D. (author)This work aims to provide guidelines on the design of wideband flat lenses based on artificial dielectric layers (ADLs). Planar lenses based on metasurfaces are typically narrowband, due to the phase wrapping over the period of 2\pi that is strongly frequency-dependent. On the contrary, true-time-delay (TTD) planar lenses, which do not resort...journal article 2024
- document
-
Hu, Weiya (author), Coco Martin, C.M. (author), Cavallo, D. (author)A semi-analytical method is presented for the design of gradient index (GRIN) flat lenses. Closed-form expressions are derived to define the refractive index distribution of the lens, for several cases: collimating lenses with on-axis feed, collimating lenses with off-axis feed, lenses converting spherical wavefronts with different...journal article 2024
- document
-
Wang, Xiangwen (author)Increasing wireless communication requirements of data rates, capacity and coverage, and evolution and maturation of wireless equipment prompt wireless communication research insight concentrating on millimeter wave (mm-wave) frequency. However, high reflection coefficients and high path loss cause large shadow areas (e.g. behind the buildings)...master thesis 2023
- document
-
Kamminga, Thomas (author)The observations of the Event Horizon Telescope led to the first mages of a black hole, an object with so much gravity that not even light can escape it. These images remain fuzzy but clearly show the shadow of a black hole with a bright disk and will only improve in quality over time. We want to be able to deduce, from the images, the following...bachelor thesis 2022
- document
-
Calcabrini, A. (author), Cardose, Ruben (author), Gribnau, David (author), Babal, Pavel (author), Manganiello, P. (author), Zeman, M. (author), Isabella, O. (author)The accurate computation of the irradiance incident on the surface of photovoltaic modules is crucial for the simulation of the energy yield of a photovoltaic system. Depending on the geometrical complexity of the surroundings, different approaches are commonly employed to calculate the irradiance on the photovoltaic system. In this article,...journal article 2022
- document
-
Tavasszy, Matthias (author)Global Illumination provides natural and more realistic illumination of a scene by simulating the bouncing of light between surfaces. Due to its complex nature, it still remains a challenge to simulate this effect with real-time frame rates even on modern-day hardware. Existing methods are noisy and either require extensive filtering or long...master thesis 2021
- document
-
Oosterlee, Oxana (author)Solar cells are usually used as power source, but can be used for sensing as well. We propose a novel indoor tracking system that tracks people by using the change in output caused by their shadows. First, we develop a simulator to determine how the solar cells should be positioned in the tracking environment to get the best detection rate. This...master thesis 2021
- document
-
Jense, Riley (author)Mirror anamorphosis is characterised by a distorted projection, where the combination of a mirror and a specific viewpoint lets the observer see the undistorted image. The use of this technique and complex perspective in general has gone from being niche to becoming mainstream. Raytracing poses itself as a solution to solving the math for such...bachelor thesis 2021
- document
-
Jia, Zhoufan (author)Suppose we have a target radiance distribution, a light source, and a plane for receiving light. How do we design a reflector that can give a similar result as the target radiance distribution? The inverse reflector problem is of high interest for light designers and related industries, such as lamp manufacture, headlight and street light design...master thesis 2021
- document
-
Klapwijk, M.D. (author), Lemaire, Sébastien (author)Increased graphical capabilities of contemporary computer hardware make ray tracing possible for a much wider range of applications. In science, and numerical fluid mechanics in particular, visual inspections still play a key role in both understanding flows, predicted by computational fluid dynamics, exhibiting features observable in real-life,...journal article 2021
- document
-
Aslan, Y. (author), Puskely, J. (author), Roederer, A.G. (author), Yarovoy, Alexander (author)The effect of forming single and multi-lobe beam<br/>patterns at mm-wave base station antennas on the received signal<br/>strength and co-channel interference is studied for mm-wave urban outdoor environments. A sample, simplified urban city model is used with randomly selected user positions. Ray tracing simulations are performed to analyze the...conference paper 2020
- document
-
Haji Aghajany, S. (author), Amerian, Yazdan (author)Tropospheric signals are considered as one of the most important performance limitations to compute the deformations caused by earthquake, subsidence, volcano, and so on using interferometric synthetic aperture radar (InSAR) technique. Various correction methods have been proposed to reduce the effect of these signals in displacement fields...journal article 2020
- document
-
Mout, B.M. (author)To predict the quality of an optical system we need to simulate the effects of aberrations and diffraction. Aberrations can be calculated by tracing rays from a source point through a digital model of the system and evaluating the spot size of these rays on the detector. For a system without aberrations, the rays will intersect at a single point...doctoral thesis 2019
- document
-
Yang, M. (author), López-Dekker, Paco (author), Dheenathayalan, P. (author), Biljecki, Filip (author), Liao, Mingsheng (author), Hanssen, R.F. (author)Persistent scatterers (PSs) are coherent measurement points obtained from time series of satellite radar images, which are used to detect and estimate millimeter-scale displacements of the terrain or man-made structures. However, associating these measurement points with specific physical objects is not straightforward, which hampers the...journal article 2019
- document
-
Zhang, Huasheng (author)In this work, a MATLAB based graphical user interface (GUI) tool is built to analyze Quasi-optical (QO) systems in reception with the Fourier Optics (FO) and Geometrical Optics (GO) methods. Five canonical QO components are discussed, namely parabolic reflectors, elliptical lenses, hemispherical lenses, hyperbolic lenses, and elliptical mirrors....master thesis 2018
- document
-
van Marrewijk, Gijsbert (author)Launch costs for high-resolution space telescopes for Earth observation can be reduced when the telescope mirrors are made deployable. However, such a system is subject to optical aberrations that decreases image quality. To counter these aberrations, an Aberration Correction System (ACS) is proposed that uses a deformable mirror (DM) which is...master thesis 2018
- document
-
Mout, B.M. (author), Wick, Michael (author), Bociort, F. (author), Petschulat, Joerg (author), Urbach, Paul (author)We present a method for simulating multiple diffraction in imaging systems based on the Huygens–Fresnel principle. The method accounts for the effects of both aberrations and diffraction and is entirely performed using Monte Carlo ray tracing.We compare the results of this method to those of reference simulations for field propagation through...journal article 2016
- document
-
Scharpf, B.J. (author)Throughout the history of exploration for hydrocarbons, illumination and imaging in structurally complex geology with high-velocity contrasts has been a challenge. Recently introduced technological innovations such as dual-sensor streamers towed behind seismic vessels, provide new means to tackle these problems. Separating wavefields into...master thesis 2013
- document
-
Bikker, J. (author)This thesis describes efficient rendering algorithms based on ray tracing, and the application of these algorithms to real-time games. Compared to rasterizationbased approaches, rendering based on ray tracing allows elegant and correct simulation of important global effects, such as shadows, reflections and refractions. The price for these...doctoral thesis 2012
- document
-
Ramezani, H. (author), Leus, G. (author)In this paper, we analyze the problem of acoustic ranging between sensor nodes in an underwater environment. The underwater medium is assumed to be composed of multiple isogradient sound speed profile (SSP) layers where in each layer the sound speed is linearly related to the depth. Furthermore, each sensor node is able to measure its depth and...journal article 2012
Pages
- 1
- 2