Search Results - "Hogda, K. A."

A ground-validated NDVI dataset for monitoring vegetation dynamics and mapping phenology in Fennoscandia and the Kola peninsula by Beck, P. S. A., Jönsson, P., Høgda, K.-A., Karlsen, S. R., Eklundh, L., Skidmore, A. K.

“…An NDVI dataset covering Fennoscandia and the Kola peninsula was created for vegetation and climate studies, using Moderate Resolution Imaging…”
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Monitoring the spatio-temporal dynamics of geometrid moth outbreaks in birch forest using MODIS-NDVI data by Jepsen, J.U., Hagen, S.B., Høgda, K.A., Ims, R.A., Karlsen, S.R., Tømmervik, H., Yoccoz, N.G.

“…Defoliation caused by repeated outbreaks of cyclic geometrid moths is the most prominent natural disturbance factor in the northern-boreal birch forest…”
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Above ground biomass changes in the mountain birch forests and mountain heaths of Finnmarksvidda, northern Norway, in the period 1957–2006 by Tømmervik, H., Johansen, B., Riseth, J.Å., Karlsen, S.R., Solberg, B., Høgda, K.A.

“…Birch forests cover large areas of the northern Fennoscandia and the mountain birch ( Betula pubescens ssp. czerepanovii) often forming the altitudinal and…”
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Growing seasons of Nordic mountain birch in northernmost Europe as indicated by long-term field studies and analyses of satellite images by Shutova, E, Wielgolaski, F. E, Karlsen, S. R, Makarova, O, Berlina, N, Filimonova, T, Haraldsson, E, Aspholm, P. E, Flø, L, Høgda, K. A

“…The phenophases first greening (bud burst) and yellowing of Nordic mountain birch (Betula pubescens ssp.tortuosa, also called B. p. ssp. czerepanovii) were…”
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Non-Gaussian signal statistics in ocean SAR imagery by Eltoft, T., Hogda, K.A.

“…The authors have studied the significance of non-Gaussian signal statistics in some synthetic aperture radar (SAR) images of the ocean surface. The study…”
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From Glacier Facies to SAR Backscatter Zones via GPR by Langley, K., Hamran, S.-E., Hogda, K.A., Storvold, R., Brandt, O., Kohler, J., Hagen, J.O.

“…We present a comparison between data acquired with frequency-modulated ground-penetrating radar (GPR) and satellite synthetic aperture radar (SAR). Both radars…”
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InSAR for estimation of changes in snow water equivalent of dry snow by Guneriussen, T., Hogda, K.A., Johnsen, H., Lauknes, I.

“…This paper describes the theoretical relation between interferometric phase and changes in snow water equivalent (SWE) and show results from experiments using…”
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An approximate analytical method for correcting distortion in synthetic-aperture-radar ocean wave spectral peaks by RUFENACH, C, JOHNSEN, H, HØGDA, K. A

“…Ocean spectral peaks extracted from synthetic aperture radar (SAR) imagery exhibit a wavenumber rotation and shift relative to the true peaks due to…”
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Vegetation Changes in the Nordic Mountain Birch Forest: the Influence of Grazing and Climate Change by Tømmervik, H., Johansen, B., Tombre, I., Thannheiser, D., Høgda, K. A., Gaare, E., Wielgolaski, F. E.

“…The study focuses on vegetation changes in the Nordic mountain birch forest in northern Norway, covering a period of more than 40 yr. The study area comprises…”
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Sar Remote Sensing of Snow Parameters in Norwegian Areas - Current Status and Future Perspective by Storvold, R., Malnes, E., Larsen, Y., Høgda, K. A., Hamran, S. E., Müller, K., Langley, K. A.

“…The paper present results from a series of European and national projects on remote sensing of snow parameters. Currently, satellite borne SAR data are only…”
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High-resolution satellite imagery for detection of tracks and vegetation damage caused by all-terrain vehicles (ATVs) in Northern Norway by Tømmervik, H., Johansen, B., Høgda, K.A., Strann, K.B.

“…Use of all‐terrain vehicles (ATVs) in vulnerable environments may cause vegetation and soil erosion that will last for a long time. In northern parts of…”
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An approximate analytical method for correcting distortion in synthetic-aperture-radar ocean wave spectral peaks by Rufenach, Clifford, Johnsen, Harald, Hogda, K. A.

“…Ocean spectral peaks extracted from synthetic aperture radar (SAR) imagery exhibit a wavenumber rotation and shift relative to the true peaks due to…”
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Improved monitoring of vegetation dynamics at very high latitudes: A new method using MODIS NDVI by Beck, Pieter S.A., Atzberger, Clement, Høgda, Kjell Arild, Johansen, Bernt, Skidmore, Andrew K.

“…Current models of vegetation dynamics using the normalized vegetation index (NDVI) time series perform poorly for high-latitude environments. This is due…”
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Monitoring vegetation changes in Pasvik (Norway) and Pechenga in Kola Peninsula (Russia) using multitemporal Landsat MSS/TM data by Tømmervik, Hans, Høgda, Kjell Arild, Solheim, Inger

“…During the period 1973–1999, the effects of air pollution on the terrestrial ecosystems in the border areas of Norway and Russia have been investigated by the…”
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length of growing season and adult sex ratio affect sexual size dimorphism in moose by Garel, Mathieu, Solberg, Erling Johan, SÆther, Bernt-Erik, Herfindal, Ivar, Høgda, Kjell-Arild

“…While factors affecting body growth have been extensively studied, very little is known about the factors likely to affect the sexual size dimorphism (SSD) in…”
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Use of C-Band Ground Penetrating Radar to Determine Backscatter Sources Within Glaciers by Langley, K., Hamran, S.-E., Hogda, K.A., Storvold, R., Brandt, O., Hagen, J.O., Kohler, J.

“…The question of penetration of synthetic aperture radar (SAR) signals at C-band frequency into polar glaciers is addressed by comparing ground penetrating…”
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Results from inverting ERS-1 SAR image mode data into directional ocean wave spectra by Johnsen, H., Hogda, K.-A.

“…Results from validating the ocean wave spectra derived from ERS-1 SAR image mode data are presented. The wave spectra are obtained by combining numerical wave…”
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An Approximate Analytical Method For Correcting Distortion In Sar Ocean Wave Spectral Peaks by Rufenach, C., Johnsen, H., Hogda, K.A.

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A monitoring system for glaciers on Svalbard based on Envisat ASAR wide swath data by Hindberg, H., Malnes, E., Hogda, K. A.

“…In this paper, we propose a method to monitor the extent of different facies on glaciers on Svalbard. The extent of the firn facies can be used as an indicator…”
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Growing-season trends in Fennoscandia 1982–2006, determined from satellite and phenology data by Karlsen, Stein Rune, Høgda, Kjell Arild, Wielgolaski, Frans Emil, Tolvanen, Anne, Tømmervik, Hans, Poikolainen, Jarmo, Kubin, Eero

“…The study area of Fennoscandia is a heterogeneous climatic region. To map the linear trends in onset, end, and length of the growing season in Fennoscandia,…”
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