Sökning: "data inversion"

Visar resultat 6 - 10 av 128 avhandlingar innehållade orden data inversion.

  1. 6. Airborne Gravity Gradient, Magnetic and VLF datasets : Case studies of modelling, inversion and interpretation

    Författare :Sayyed Mohammad Abtahi; Thomas Kalscheuer; Laust Pedersen; Jochen Kamm; Thorkild Rasmussen; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; VLF; gravity gradient; magnetic; airborne; inversion; non-uniqueness;

    Sammanfattning : Northern Sweden is one of the largest hosts for mineral resources in Europe and always has been an interesting area for researchers from various disciplines of Earth sciences. This dissertation is a comprehensive summary of three case study papers on airborne VLF, gravity gradient and magnetic data in the area. LÄS MER

  3. 7. Three-Dimensional Modelling and Inversion of DC resistivity and Time Domain EM data using Multi-Resolution Framework

    Författare :Jingyu Gao; Thorkild Maack Rasmussen; Maxim Smirnov; Bülent Tezkan; Luleå tekniska universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; DC Resistivity; time-domain electromagnetic; forward modelling; data inversion; Prospekteringsgeofysik; Exploration Geophysics;

    Sammanfattning : 3-D forward modelling and inversion techniques play an important role in data interpretation, but they are still computationally challenging tasks. Therefore, this thesis aims to improve forward modelling and inversion performance using novel multi-resolution (MR) grid approach. LÄS MER

  4. 8. Natural and Controlled Source Magnetotelluric Data Processing and Modeling

    Författare :Chunling Shan; Thomas Kalscheuer; Laust Pedersen; Mehrdad Bastani; Thorkild Rasmussen; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Geophysics; Airborne Electromagnetic Method; Radio Magnetotellurics; Controlled Source Magnetotellurics; Electrical Resistivity Tomography; Moving Magnetotellurics; 2D inversion; 3D inversion;

    Sammanfattning : In this thesis, four studies using different geophysical electromagnetic methods are presented. In the first study dealing with airborne measurements, the noise response due to the rotation of the aircraft and the aircraft itself as a metallic conductive body on the Earth's electromagnetic response in very low frequency and low frequency band was investigated. LÄS MER

  5. 9. Spatial Mixture Models with Applications in Medical Imaging and Spatial Point Processes

    Författare :Anders Hildeman; Göteborgs universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Non-Gaussian; Bayesian level set inversion; Point processes; Substitute CT; Finite mixture models; Spatial statistics; Gaussian fields; Non-Gaussian;

    Sammanfattning : Finite mixture models have proven to be a great tool for both modeling non-standard probability distributions and for classification problems (using the latent variable interpretation). In this thesis we are building spatial models by incorporating spatially dependent categorical latent random fields in a hierarchical manner similar to that of finite mixture models. LÄS MER

  7. 10. Inversion of Magnetotelluric Data Constrained by Borehole Logs and Reflection Seismic Sections

    Författare :Ping Yan; Thomas Kalscheuer; Laust Pedersen; Maria Garcia Juanatey; Andreas Junge; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Magnetotellurics; constrained inversion; borehole logs; seismic; COSC; Alnö alkaline and carbonatite; airborne VLF; Geofysik med inriktning mot fasta jordens fysik; Geophysics with specialization in Solid Earth Physics;

    Sammanfattning : This thesis presents two new algorithms for doing constrained Magnetotelluric (MT) inversion based on an existing Occam 2D inversion program. The first algorithm includes borehole resistivity logs as prior information to constrain resistivity directly in the vicinity of boreholes. LÄS MER