A5028468973- Arctic and Antarctic ice dynamics
- Cryospheric studies and observations
- Synthetic Aperture Radar (SAR) Applications and Techniques
- Soil Moisture and Remote Sensing
- Climate change and permafrost
- Ocean Waves and Remote Sensing
- Remote Sensing and LiDAR Applications
- Oceanographic and Atmospheric Processes
- Methane Hydrates and Related Phenomena
- Soil Geostatistics and Mapping
- Landslides and related hazards
- Maritime Transport Emissions and Efficiency
- Geophysical and Geoelectrical Methods
- Maritime Navigation and Safety
- Ship Hydrodynamics and Maneuverability
- 3D Surveying and Cultural Heritage
- Geomagnetism and Paleomagnetism Studies
- Geophysics and Gravity Measurements
- Data Management and Algorithms
- Aeolian processes and effects
- Oil Spill Detection and Mitigation
- Tree Root and Stability Studies
- Atmospheric and Environmental Gas Dynamics
- Constraint Satisfaction and Optimization
- Scientific Research and Discoveries
Chalmers University of Technology
2015-2024
Linköping University
2021-2024
Gamma Remote Sensing (Switzerland)
2010
Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung
2010
Swedish Meteorological and Hydrological Institute
2010
Lantmännen
2007
Friedrich Schiller University Jena
2003-2004
Schiller International University
2003
ABB (Switzerland)
1993
Geological Survey of Sweden
1969-1989
A microprocessor based fault locator is described, which uses novel compensation techniques to improve accuracy. It displays the distance in percent of transmission line length, for facilitating repair and restoration following a permanent fault. Also, it pinpoints weak spots transient faults.
The Phased Array type L-band Synthetic Aperture Radar onboard the Advanced Land Observing Satellite has, since its launch, been acquiring an extensive data set of images over two forest test sites in Sweden. Remningstorp (Lat. 58deg30' N, Long. 13deg40' E) south and Krycklan 64deg14' 19deg50' north Sweden are characterized by hemiboreal boreal forests, respectively. In this paper, we have investigated signatures standwise backscatter measurements from forests with different growth stages...
High-resolution satellite images of ocean color and sea surface temperature reveal an abundance fronts, vortices filaments at scales below 10 km but measurements dynamics these are rare. There is increasing recognition the role played by small scale processes in ocean-atmosphere coupling, upper-ocean mixing vertical transports, with advanced numerical models situ observations highlighting fundamental changes when reach 1 km. Numerous scientific publications highlight global impact oceanic on...
Abstract. Arctic landfast sea ice has undergone substantial changes in recent decades, affecting stability and including potential impacts on travel by coastal populations industry roads. We present a novel approach for evaluating pan-Arctic scale using Synthetic Aperture Radar Interferometry (InSAR). Using Sentinel-1 images from spring 2017, we discriminate between bottomfast, stabilized, nonstabilized over the main marginal seas of Ocean (Beaufort, Chukchi, East Siberian, Laptev, Kara...
JERS‐1 L‐band SAR backscatter from test sites in Sweden, Finland and Siberia has been investigated to determine the accuracy level achievable boreal zone for stand‐wise forest stem volume retrieval using a model‐based approach. The extensive ground‐data imagery datasets available allowed analysis of temporal dynamics. In dense forests primarily depended on frozen/unfrozen state canopy, showing ∼4 dB difference. sparse forests, dielectric properties floor, smaller differences throughout year....
ABSTRACT In this paper an algorithm for ice/water classification of C- and L-band dual polarization synthetic aperture radar data is presented. A comparison the two different frequencies made in order to investigate potential improve results with multi-frequency data. The based on backscatter intensities co- cross-polarization autocorrelation as a texture feature. mapping between image features neural network. Accurate maps both are produced by generally agree very well. Differences found...
The main challenging problems in ocean current retrieval from along-track interferometric (ATI)-synthetic aperture radar (SAR) are phase calibration and wave bias removal. In this paper, a method based on differential InSAR (DInSAR) technique for correcting the offset its variation is proposed. removal assessed using two different Doppler models wind sources. addition to provided by an atmospheric model, speed used correction work extracted calibrated SAR backscatter. This demonstrates that...
AbstractIn this study, synthetic aperture radar (SAR) data from the Advanced Land Observing Satellite (ALOS) and Envisat, RADARSAT-2, TerraSAR-X satellites were compared to evaluate their usefulness for sea-ice monitoring in Baltic Sea. Radar signature characteristics at different frequencies, polarizations, spatial resolutions are presented three examples 2009. C-band like-polarization data, which have been used operational mapping since early 1990s, serve as a reference. Advantages...
Wind vector fields derived from synthetic aperture radar (SAR) sensors show variations at smaller scales than most other globally available surface wind sources. However, few studies have been devoted to the investigation of accuracy SAR-derived different and how they compare with data. In order investigate these issues, an algorithm for retrieval vectors has developed, a quality assessment between retrievals in situ, scatterometer, numerical weather model (NWM) data performed. The...
Areal matching by phase correlation and feature tracking are two complementary methods used to measure sea ice drift between synthetic aperture radar images. This paper evaluates a new algorithm that combines the methods. is improved handle large motions rotated ice. It shown areal rotation can be resolved using frequency-domain approach. Image segmentation prerequisite for achieved method performs better than Otsu's two-component Gaussian mixture distributions. A circular weighted median...
Between 2006 and 2011, the Advanced Land Observing Satellite (ALOS) Phased Array L-type Synthetic Aperture Radar (PALSAR) instrument acquired multi-temporal datasets under several environmental conditions multiple configurations of look angle polarization. The extensive archive SAR backscatter observations over forest test sites Krycklan (boreal) Remningstorp (hemi-boreal), Sweden, was used to assess retrieval stem volume at stand level. based on inversion a simple Water Cloud Model with...
One of the challenges in ocean surface current retrieval from synthetic aperture radar (SAR) data is estimation and removal wave-induced Doppler centroid (DC). This article demonstrates empirically relationship between dc derived spaceborne X-band InSAR wind waves. In this study, we analyzed over 300 TanDEM-X image pairs. It found that general characteristics estimated follow theoretically expected variation with incidence angle, speed, direction. An empirical geophysical model function...
This article presents the first direct comparison of sea surface radial velocity (RVL) derived from two satellite SAR systems Sentinel-1 and TanDEM-X, operating at different frequencies imaging modes. The RVL is Doppler centroid (Dc) provided in OCN product along-track interferometric phase TanDEM-X. carried out using unique opportunistic acquisitions, collocated space time, over three sites located Iceland Sea, Pentland Firth, Kattegat Sea. First, it observed that both satellites biased,...
Detailed mapping of fast-ice deformation can be used to characterize the rheological behavior fast ice and subsequently improve sea modeling. This study uses interferometric synthetic aperture radar map with unprecedented spatial resolution (meter range) sensitivity (cm-mm range). Two acquisitions, each a temporal baseline 24 h, were performed by X-band SAR satellite constellation Cosmo-SkyMed over northeast Bay Bothnia in middle 2012 season. The first interferogram shows due force from...
Radar altimetry in the context of sea ice has mostly been exploited to retrieve basin-scale information about thickness. In this paper, we investigate sensitivity altimetric waveforms small-scale changes (a few hundred meters 10 km) surface. Near-coincidental synthetic aperture radar (SAR) imagery and CryoSat-2 data Beaufort Sea are used identify study spatial evolution altimeter over these features. Open water thin features easily identified because their high peak power waveforms. Thicker...
Automatic and visual sea ice classification of SAR imagery is impeded by the incidence angle dependence backscatter intensities. Knowledge angular different types therefore necessary to account for this effect. While consistent estimates exist HH polarization types, they are lacking HV data, especially multiyear ice. Here we investigate smooth rough/deformed first-year ages wintertime dual-polarization Sentinel-1 C-band in Beaufort Sea. Assuming a linear relationship, determined using...
Multitemporal radar data from the Japanese Earth Resources Satellite (JERS) satellite period 1993 to 1998 have been used investigate if L-band interferometric coherence with a 44-day temporal baseline is suitable for estimations of growing-stock volume in boreal forest. Two forest regions north Krasnoyarsk Siberia as test areas. Seasonal variations repeat-pass studied, and comparison C-band European Remote sensing 1 2 (ERS-1/2) tandem missions 1997 has done. JERS winter shows clear...
An extensive dataset of images acquired by the Advanced Land Observing Satellite (ALOS) Phased Array type L-band Synthetic Aperture Radar (PALSAR) is investigated for clear-cut detection in county Västerbotten, Sweden. Strong forest/non-forest contrast and temporal consistency were found Fine Beam Dual HV-polarized backscatter summer/fall. In consequence a between image acquisitions, HV-backscatter dropped most cases 2 3 dB. Thus, simple thresholding algorithm that exploits time series...
Bottomfast sea ice is an integral part of many near-coastal Arctic ecosystems with implications for subsea permafrost, coastal stability and morphology. also great relevance to over-ice travel by communities, industrial roads, marine habitats. There are currently large uncertainties around where how much bottomfast present in the due lack effective approaches detecting on spatial scales. Here, we suggest a robust method capable using spaceborne synthetic aperture radar interferometry. This...
We describe a P-, L- and C-band radar, BorealScat, designed for polarimetric time-series measurements of forests. Radar tomography is implemented with vertical antenna array, which provides the scattering distribution. To minimize temporal decorrelation, radar performs simultaneous reflected signals using all array elements. The system 20-port vector network analyzer (VNA) stepped-frequency waveform. It has two 20-element arrays: one optimized P- L-bands C-band. arrays are installed on 50-m...
A controlled experiment has been performed to quantify the ability detect clear-cuts using ALOS PALSAR data. The consisted of 8 old spruce dominated stands, each with a size about 1.5 ha, located at test site in southern Sweden. Four stands were clear-felled and remaining left untreated for reference. time series images was acquired prior to, during, after treatment, including 7 fine beam single polarization (FBS, look angle 34.3deg, HH-polarization) SAR images. results clearly show that...
Two field experiments have been conducted in Sweden to allow an evaluation of the backscatter signatures wind-thrown forest from L-band, C-band and X-band Synthetic Aperture Radar. When trees are felled backscattered signal TerraSAR-X (X-band) increase with about 1.5 dB, while for ALOS PALSAR (L-band) a decrease same amount is observed. Radar images fine spatial resolution also show shadowing effects that should be possible use identification storm forest.