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di Biase, V. (author), Hanssen, R.F. (author)Ghana's coastline has been facing erosion and sedimentation phenomena for several decades, resulting in a serious threat to life and property considering that major urban settlements are located on the coast. In this region, there has been a lack of emphasis on comprehensive, large-scale investigations into coastal changes: prior research has...journal article 2024
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Brouwer, W.S. (author), Wang, Y. (author), van Leijen, F.J. (author), Hanssen, R.F. (author)InSAR enables the estimation of displacements of (objects on) the earth's surface. To provide reliable estimates, both a stochastic and mathematical model are required. However, the intrinsic problem of InSAR is that both are unknown. Here we derive the Variance-Covariance Matrix (VCM) for double differenced phase observations for an arc, i.e...conference paper 2023
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Kuschnerus, M. (author), Lindenbergh, R.C. (author), Vos, S.E. (author), Hanssen, R.F. (author)In the view of climate change, understanding and managing effects on coastal areas and adjacent cities is essential. Permanent Laser Scanning (PLS) is a successful technique to not only observe notably sandy coasts incidentally or once every year, but (nearly) continuously over extended periods of time. The collected point cloud observations...journal article 2023
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Conroy, Philip (author), van Diepen, S.A.N. (author), Hanssen, R.F. (author)We present SPAMS: Simple Parameterization for the Motion of Soils, a model to describe the motion of deformable soils in the Vadose zone, mainly peat and clay, herein called shallow soft soils. The SPAMS model estimates the reversible and irreversible vertical component of surface displacement to within sub-centimetre RMSE, using only four...journal article 2023
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Conroy, Philip (author), van Diepen, S.A.N. (author), van Leijen, F.J. (author), Hanssen, R.F. (author)We introduce the term loss-of-lock to describe a specific form of coherence loss that results in the breakage of a synthetic aperture radar interferometric (InSAR) time series. Loss-of-lock creates a specific pattern in the coherence matrix of a multilooked distributed scatterer (DS) by which it may be detected. Along with identification, we...journal article 2023
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Mulder, G. (author), van Leijen, F.J. (author), Hanssen, R.F. (author)The observed phase in time series of interferometric synthetic aperture radar (InSAR) products is a superposition of various components. Differential topography, line-of-sight displacements, and differential atmospheric delays are the main contributions and need to be disentangled to derive accurate digital elevation model (DEM), deformation,...journal article 2023
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Brouwer, W.S. (author), Hanssen, R.F. (author)The estimation of displacement vectors for (objects on) the Earth's surface using satellite InSAR requires geometric transformations of the observables based on orbital viewing geometries. Usually, there are insufficient viewing geometries available for full 3-D reconstruction, leading to nonunique solutions. Currently, there is no...journal article 2023
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Yang, Mengshi (author), Liao, Mingsheng (author), Chang, Ling (author), Hanssen, R.F. (author)Multi-epoch interferometric synthetic aperture radar (InSAR) is a highly effective technique for monitoring deformation in urban areas. However, interpreting InSAR deformation can be challenging due to various factors, including inherent geometric imaging distortion, the intricate structure and deformation properties of targets in urban...journal article 2023
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Reinders, K.J. (author), Giardina, Giorgia (author), Zurfluh, Florian (author), Ryser, Jurg (author), Hanssen, R.F. (author)In the planning stage of new infrastructure or when designing renovation of existing infrastructure, information about existing slope movements or settlements is essential to make informed design decisions. Interferometric<br/>Synthetic Aperture Radar (InSAR) techniques can be of value to identify these risks in an early stage of a project....journal article 2022
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Conroy, Philip (author), van Diepen, S.A.N. (author), Van Asselen, Sanneke (author), Erkens, Gilles (author), van Leijen, F.J. (author), Hanssen, R.F. (author)Phase unwrapping, also known as ambiguity resolution, is an underdetermined problem in which assumptions must be made to obtain a result in SAR interferometry (InSAR) time series analysis. This problem is particularly acute for distributed scatterer InSAR, in which noise levels can be so large that they are comparable in magnitude to the...journal article 2022
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van Zwieten, G.J. (author), van Brummelen, E. Harald (author), Hanssen, R.F. (author)Earthquakes cause lasting changes in static equilibrium, resulting in global deformation fields that can be observed. Consequently, deformation measurements such as those provided by satellite based InSAR monitoring can be used to infer an earthquake's faulting mechanism. This inverse problem requires a numerical forward model that is both...journal article 2022
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Hu, F. (author), van Leijen, F.J. (author), Chang, L. (author), Wu, Jicang (author), Hanssen, R.F. (author)Synthetic aperture radar (SAR) missions with short repeat times enable opportunities for near real-time deformation monitoring. Traditional multitemporal interferometric SAR (MT-InSAR) is able to monitor long-term and periodic deformation with high precision by time-series analysis. However, as time series lengthen, it is time-consuming to...journal article 2022
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Czikhardt, Richard (author), van der Marel, H. (author), Papco, Juraj (author), Hanssen, R.F. (author)Compact and low-cost radar transponders are an attractive alternative to corner reflectors (CRs) for interferometric synthetic aperture radar (InSAR) deformation monitoring, datum connection, and geodetic data integration. Recently, such transponders have become commercially available for C-band sensors, which poses relevant questions on...journal article 2022
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Mulder, G. (author), van Leijen, F.J. (author), Barkmeijer, Jan (author), De Haan, Siebren (author), Hanssen, R.F. (author)Numerical weather prediction (NWP) models are used to predict the weather based on current observations in combination with physical and mathematical models. Yet, they are limited by the spatial density and the accuracy of the available observations. Satellite radar interferometry (InSAR) is known to be extremely sensitive to the 3D...journal article 2022
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Conroy, Philip (author), van Diepen, S.A.N. (author), van Leijen, F.J. (author), Hanssen, R.F. (author)We present a novel InSAR processing scheme which combines point scatterer (PS) and distributed scatter (DS) approaches in a hybrid framework along with contextual information about the environment under study. Data such as land parcel divisions, precipitation and temperature are integrated into the processing pipeline in order to produce...conference paper 2022
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Hu, F. (author), Helfer, K.C. (author), Siebesma, A.P. (author), Hanssen, R.F. (author)Atmospheric delay has a profound impact on synthetic aperture radar (SAR) interferometry, inducing a spatial signal that significantly devaluates interferometric products. While the wide-scale variability of the atmosphere can be adequately modeled with global or regional weather models, it is especially the turbulent and convective part of the...journal article 2022
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Hanssen, J.L.J. (author), van Prooijen, Bram (author), Volp, Nicolette Dominique (author), de Vet, P.L.M. (author), Herman, P.M.J. (author)Although tidal flats appear homogeneous from a distance, morphological variations are found on various spatial scales. These are driven by physical and/or biological processes. In this paper, we consider the creeks that are present on fringing tidal flats and which are orientated approximately perpendicular to the main channel. To explain why...journal article 2022
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van Natijne, A.L. (author), Bogaard, T.A. (author), van Leijen, F.J. (author), Hanssen, R.F. (author), Lindenbergh, R.C. (author)Landslides are a major geohazard in hilly and mountainous environments. In-situ inspection of downslope motion is costly, sometimes dangerous and, requires prior knowledge of the existence of a landslide. Remote sensing from space is a way to detect and characterize landslides systematically at large scale. Interferometric Synthetic Aperture...journal article 2022
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di Biase, V. (author), Hanssen, R.F. (author)Environmental effects and climate change are lately representing an increasing strain on coastal areas, whose topography strongly depends on these conditions. However, the processes by which weather and environmental phenomena influence the highly variable beach morphology are still unknown. Continuous monitoring of the beach environment is...journal article 2021
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Czikhardt, Richard (author), van der Marel, H. (author), van Leijen, F.J. (author), Hanssen, R.F. (author)The estimation of Signal-to-Clutter Ratio (SCR) of a radar point target, such as a corner reflector, is an essential step for synthetic aperture radar (SAR) interferometry and positioning, as it influences the phase measurement variance as well as the absolute positioning precision. The standard method to estimate the SCR of a point target...journal article 2021