Sökning: "aperture"

Visar resultat 1 - 5 av 162 uppsatser innehållade ordet aperture.

  1. 1. Real-Time Navigation for Swarms of Synthetic Aperture Radar (SAR) Satellites

    Master-uppsats, Luleå tekniska universitet/Rymdteknik

    Författare :Antoni Eritja Olivella; [2024]
    Nyckelord :SAR; Real-time orbit determination; Real-time baseline determination; swarms; satellite; formation flying;

    Sammanfattning : The pursuit of precision and flexibility in satellite missions has led to an increased number of formation flying missions being developed. These systems consist of multiple satellites flying at close distances (from a few kilometres to a few meters) to achieve common objectives. LÄS MER

  3. 2. Evaluating aperture shape controller (ASC) in modulated radiation treatments

    Master-uppsats,

    Författare :Vilma Andrén Cederholm; [2023-09-28]
    Nyckelord :Medical physics;

    Sammanfattning : To decrease aperture complexity, the aperture shape controller (ASC) is a recently introduced function in Eclipse external beam planning (Varian Medical Systems, Palo Alto, USA). ASC works within the photon optimizer, minimizing distances between adjacent leaf tips of the MLC. LÄS MER

  4. 3. Development and Implementation of Techniques for the Simulation and Processing for Future SAR Systems

    Master-uppsats, Luleå tekniska universitet/Institutionen för system- och rymdteknik

    Författare :Tim Kinnunen; [2023]
    Nyckelord :Synthetic Aperture Radar; SAR; Reverse Backprojection Algorithm; RBPA; Backprojection Algorithm; SAR simulator; SAR processing;

    Sammanfattning : Synthetic Aperture Radar (SAR) is a type of radar system that can generate high-resolution images with which one can detect subtle changes on the scale of centimetres from space. It can operate in any weather condition and during both day and night, making it unique compared to optical sensors. LÄS MER

  5. 4. ISAR Imaging Enhancement Without High-Resolution Ground Truth

    Master-uppsats, Linköpings universitet/Datorseende

    Författare :Moltas Enåkander; [2023]
    Nyckelord :SAR; SAR Imaging; ISAR; ISAR Imaging; Machine learning; Convolutional neural network; CNN; neural network; Super resolution; Unsupervised learning;

    Sammanfattning : In synthetic aperture radar (SAR) and inverse synthetic aperture radar (ISAR), an imaging radar emits electromagnetic waves of varying frequencies towards a target and the backscattered waves are collected. By either moving the radar antenna or rotating the target and combining the collected waves, a much longer synthetic aperture can be created. LÄS MER

  7. 5. Monitoring deforestation in the Serranía de Chiribiquete in northern Colombian Amazon using time series analysis of satellite data

    Master-uppsats, Lunds universitet/Institutionen för naturgeografi och ekosystemvetenskap

    Författare :Yuyang Qian; [2023]
    Nyckelord :Physical Geography and Ecosystem analysis; CCDC; Forest loss; Landsat; Sentinel-1; Change detection; NNP; FARC; Earth and Environmental Sciences;

    Sammanfattning : Deforestation monitoring is of significant importance for the ecosystem, climate change,and policy-making. The availability of optical and synthetic aperture radar (SAR) satellite remote sensing images, along with the development of time series change detection methods, has contributed to the increasing popularity of time series analysis in forest disturbance monitoring. LÄS MER