Browsing NTNU Open by Author "Mogstad, Aksel Alstad"
Now showing items 1-15 of 15
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A new classification tool in underwater Archaeology-Critical experiments with Underwater Hyperspectral Imaging on a selection of Archaeological material from Norway
Røste, Ola Nordby (Master thesis, 2021)Denne oppgaven fokuserer på marinarkeologi, bruk av teknologi og kritiske eksperimenter med undervanns hyperspektral avbildning (UHI). Marin- eller undervannsarkeologi har blitt svært teknologisk og er helt avhengig av ... -
Aerial & Underwater Hyperspectral Imagery For Shallow Benthic Nature Type Mapping
Bjerkvoll, Mikkel (Master thesis, 2022)Natur i Norge (NiN) systemet klassifiserer naturtyper basert på miljøvariabler. Storskala kartlegging av bentiske naturtyper er vanskelig, ettersom lys utslukkes fort på dype områder, og grunt vann er vanskelig å forsere. ... -
Mapping distribution patterns of brittle stars using ROV-based imaging
Marnor, Camilla Mult (Master thesis, 2022)Stor etterspørsel etter marine økosystemtjenester og konkurranse om havrom presser marine økosystemer til det ytterste. Det er et behov for effektive metoder for identifisering, kartlegging og overvåking for å forstå ... -
Mapping of Zostera habitat in the Sublittoral Zone using Underwater Hyperspectral Imaging and Unmanned Surface Vehicle
Søreng, Marte Opsahl (Master thesis, 2022)Sjøgressenger over hele verden trues av menneskeskapte habitatødeleggelser og global oppvarming. Det er et behov for kartlegging med høy oppløsning for å øke overvåkningsevnene våre og fylle kunnskapshull knyttet til disse ... -
Mapping the Historical Shipwreck Figaro in the High Arctic Using Underwater Sensor-Carrying Robots
Mogstad, Aksel Alstad; Ødegård, Øyvind; Nornes, Stein Melvær; Ludvigsen, Martin; Johnsen, Geir; Sørensen, Asgeir Johan; Berge, Jørgen (Peer reviewed; Journal article, 2020)In 2007, a possible wreck site was discovered in Trygghamna, Isfjorden, Svalbard by the Norwegian Hydrographic Service. Using (1) a REMUS 100 autonomous underwater vehicle (AUV) equipped with a sidescan sonar (SSS) and (2) ... -
A Methodology for Consistent Georegistration in Underwater Hyperspectral Imaging
Løvås, Håvard; Mogstad, Aksel Alstad; Sørensen, Asgeir Johan; Johnsen, Geir (Peer reviewed; Journal article, 2021)This article proposes a novel methodology for precise georegistration in underwater hyperspectral imaging (UHI) using a red–green–blue (RGB) camera to build a photogrammetry model that estimates the pose and a 3-D seabed ... -
Operative Habitat Mapping and Monitoring in the Polar Night
Johnsen, Geir; Mogstad, Aksel Alstad; Berge, Jørgen; Cohen, Jonathan H. (Chapter, 2020)The Polar Night has long been regarded as a period of no biological activity. As a logical consequence, environmental management has mainly been neglected in this period. We will use the Northguider accident in December ... -
Remote Sensing of the Tautra Ridge: An Overview of the World’s Shallowest Cold-Water Coral Reefs
Mogstad, Aksel Alstad; Løvås, Håvard; Sture, Øystein; Johnsen, Geir; Ludvigsen, Martin (Peer reviewed; Journal article, 2022)On the Tautra Ridge – a 39-100 m deep morainic sill located in the middle of the Trondheimsfjord, Norway – some of the world’s shallowest known occurrences of the scleractinian cold-water coral (CWC) Desmophyllum pertusum ... -
Shallow-Water Habitat Mapping using Underwater Hyperspectral Imaging from an Unmanned Surface Vehicle: A Pilot Study
Mogstad, Aksel Alstad; Johnsen, Geir; Ludvigsen, Martin (Journal article; Peer reviewed, 2019)The impacts of human activity on coastal ecosystems are becoming increasingly evident across the world. Consequently, there is a growing need to map, monitor, and manage these regions in a sustainable manner. In this pilot ... -
Spectral characteristics of coralline algae: a multi-instrumental approach, with emphasis on underwater hyperspectral imaging
Mogstad, Aksel Alstad (Master thesis, 2017)Coralline algae constitute a cosmopolitan group of calcifying rhodophytes (red algae) known to form important marine ecosystems. Currently, detailed knowledge of their abundance and distribution is lacking in certain regions ... -
Spectral characteristics of coralline algae: a multi-instrumental approach, with emphasis on underwater hyperspectral imaging
Mogstad, Aksel Alstad; Johnsen, Geir (Journal article; Peer reviewed, 2017)Coralline algae constitute a cosmopolitan group of calcifying rhodophytes (red algae) that display characteristic optical fingerprints due to light absorption by specific light-harvesting pigments. The spectrally conspicuous ... -
Underwater Hyperspectral Imaging as a Tool for Benthic Habitat Mapping
Mogstad, Aksel Alstad (Doctoral theses at NTNU;2021:271, Doctoral thesis, 2021)Since the 1950s, continuous technological advances have gradually improved our ability to map the seafloor and its associated benthic habitats. Historically, seafloor mapping has largely been carried out acoustically, using ... -
Underwater Hyperspectral Imaging of Arctic Macroalgal Habitats during the Polar Night Using a Novel Mini-ROV-UHI Portable System
Summers, Natalie; Johnsen, Geir; Mogstad, Aksel Alstad; Løvås, Håvard; Fragoso, Glaucia Moreira; Berge, Jørgen (Peer reviewed; Journal article, 2022)We describe an Underwater Hyperspectral Imager (UHI) deployed on an instrument-carrying platform consisting of two interconnected mini-ROVs (Remotely Operated Vehicle) for the mapping and monitoring of Arctic macroalgal ... -
Underwater hyperspectral imaging: a new tool for marine archaeology
Ødegård, Øyvind; Mogstad, Aksel Alstad; Johnsen, Geir; Sørensen, Asgeir Johan; Ludvigsen, Martin (Journal article; Peer reviewed, 2018)By applying an underwater hyperspectral imager (UHI) to a selection of archaeological artifacts, we have found spectral signatures that are representative of materials likely to be present at wreck sites. By successfully ... -
Use of different imaging systems for ROV-based mapping of complex benthic habitats
Nevstad, Malin Bø (Master thesis, 2022)Denne studien bruker mini-ROV-er, små fjernstyrte kjøretøyer som bærer kameraer med forskjellige egenskaper som undervanns hyperspektral avbildning (UHI) og høy-definisjon (HD) rød, grønn og blå (RGB) kameraer for å kartlegge ...