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Combinatorial Nonnegative Matrix-Tensor Factorization for Hyperspectral Unmixing Using a General ℓ q Norm Regularization

Gholinejad, Saeid (author), Amiri Simkooei, A. (author)

Hyperspectral unmixing (HU), an essential procedure for various environmental applications, has garnered significant attention within remote sensing communities. Among different groups of HU methods, nonnegative matrix factorization (NMF)-based ones have gained widespread popularity due to their high capability of simultaneously extracting...

journal article 2024

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Improving LiDAR height precision in urban environment: Low-cost GNSS ranging prototype for post-mission airborne laser scanning enhancement

Salehi-Dorcheabedi, Milad (author), Asgari, Jamal (author), Amiri Simkooei, A. (author), Fatemi Nasrabadi, Sayyed Bagher (author)

Although Light Detection and Ranging (LiDAR) technology is currently one of the most efficient methods for acquiring high-density point cloud, there are still challenges in terms of data reliability. In particular, the accuracy assessment of LiDAR data, especially in the height component, is one of the main issues in this context. This study...

journal article 2024

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Realistic interseismic strain rate uncertainties from inherently sparse GNSS-networks

Broerse, D.B.T. (author), D'Acquisto, Mario (author), Govers, Rob (author), Marsman, C.P. (author), Amiri Simkooei, A. (author)

Before geodetically derived strain and rotation rates can be robustly compared to geological or seismological observations, we need reliable strain rate uncertainties. Various methods exist to compute strain rates from GNSS-derived interseismic velocities, but a realistic representation of interpolation uncertainties has remained a challenge....

abstract 2023

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Characterizing seabed sediments using multi-spectral backscatter data in the North Sea

Bai, Q. (author), Mestdagh, S.M.F. (author), Snellen, M. (author), Amiri Simkooei, A. (author)

Acoustic classification using single-beam and multi-beam echosounders has been widely applied in characterizing seabed sediments. Although previous studies have shown a better discrimination of fine and coarse sediments using multi-spectral echosounder data, analysis regarding comprehensive seabed sediment properties is still needed. In this...

conference paper 2023

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Multivariate Weighted Total Least Squares Based on the Standard Least-Squares Theory

Gholinejad, Saeid (author), Amiri Simkooei, A. (author)

The weighted total least squares (WTLS) has been widely used in many geodetic problems to solve the error-in-variable (EIV) models in which both the observation vector and the design matrix contain random errors. This method is widely applied in its univariate form, where the observations and unknown coefficients appear in vector forms....

journal article 2023

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Enhancing spatial resolution of GRACE-derived groundwater storage anomalies in Urmia catchment using machine learning downscaling methods

Sabzehee, F. (author), Amiri Simkooei, A. (author), Iran Pour, S. (author), Vishwakarma, B.D. (author), Kerachian, R. (author)

The Urmia lake in north-west Iran has dried up to perilously low levels in the past two decades. In this study, we investigate the drivers behind the decline in lake water level with the help of in-situ and remote sensing data. We use total water storage (TWS) changes from the gravity recovery and climate experiment (GRACE) satellite mission....

journal article 2023

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A gap-filling algorithm selection strategy for GRACE and GRACE Follow-On time series based on hydrological signal characteristics of the individual river basins

Karimi, Hamed (author), Iran-Pour, Siavash (author), Amiri Simkooei, A. (author), Babadi, Masoud (author)

Gravity recovery and climate experiment (GRACE) and GRACE Follow-On (GRACE-FO) are Earth's gravity satellite missions with hydrological monitoring applications. However, caused by measuring instrumental problems, there are several temporal missing values in the dataset of the two missions where a long gap between the mission dataset also...

journal article 2023

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Impact of Climate Change Parameters on Groundwater Level: Implications for Two Subsidence Regions in Iran Using Geodetic Observations and Artificial Neural Networks (ANN)

Haji-Aghajany, Saeid (author), Amerian, Yazdan (author), Amiri Simkooei, A. (author)

This study aims to investigate how changes in meteorological indicators affect groundwater resources, and hence to predict groundwater levels using these indicators, particularly in regions experiencing drought and subsidence. Precipitation, temperature, evapotranspiration and precipitable water vapor (PWV) are important meteorological...

journal article 2023

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Estimating process noise variance of PPP-RTK corrections: a means for sensing the ionospheric time-variability

Sadegh Nojehdeh, Parvaneh (author), Khodabandeh, Amir (author), Khoshelham, Kourosh (author), Amiri Simkooei, A. (author)

The provision of accurate ionospheric corrections in PPP-RTK enormously improves the performance of single-receiver user integer ambiguity resolution (IAR), thus enabling fast high precision positioning. While an external provider can disseminate such corrections to the user with a time delay, it is the task of the user to accurately time...

journal article 2023

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Clearance measurement validation for highway infrastructure with use of lidar point clouds

Meinderts, J. P. (author), Lindenbergh, R.C. (author), Van Der Heide, D. H. (author), Amiri Simkooei, A. (author), Truong-Hong, Linh (author)

This paper introduces a method to automatically estimate vertical and horizontal clearances of highway viaducts and gantries from Mobile Laser Scanner (MLS) point clouds. It is essential to have accurate data on the vertical and horizontal clearances of overhead infrastructure objects along the highway. Accurate clearance data is used for...

journal article 2022

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Long-term drought monitoring of the Zayandehrud River basin (central Iran) using hydroclimatological models and satellite observations

Babadi, Masoud (author), Iran Pour, Siavash (author), Roscher, Ribana (author), Amiri Simkooei, A. (author), Karimi, Hamed (author)

Drought is one of the most complex and threatening disasters, defined as a period of drier-than-normal conditions which results in water-related problems. In addition to climate variation, human activities can cause or intensify drought through groundwater overextraction, unsupervised expansion of agricultural lands, etc. One prime example of...

journal article 2022

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Improvement of multi-gnss precision and success rate using realistic stochastic model of observations

Mirmohammadian, Farinaz (author), Asgari, Jamal (author), Verhagen, S. (author), Amiri Simkooei, A. (author)

With the advancement of multi-constellation and multi-frequency global navigation satellite systems (GNSSs), more observations are available for high precision positioning applications. Although there is a lot of progress in the GNSS world, achieving realistic precision of the solution (neither too optimistic nor too pessimistic) is still an...

journal article 2022

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Multi-GNSS-Weighted Interpolated Tropospheric Delay to Improve Long-Baseline RTK Positioning

Mirmohammadian, Farinaz (author), Asgari, Jamal (author), Verhagen, S. (author), Amiri Simkooei, A. (author)

Until now, RTK (real-time kinematic) and NRTK (Network-based RTK) have been the most popular cm-level accurate positioning approaches based on Global Navigation Satellite System (GNSS) signals in real-time. The tropospheric delay is a major source of RTK errors, especially for medium and long baselines. This source of error is difficult to...

journal article 2022

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Establishment of a corrective geoid surface by spline approximation of Iranian GNSS/levelling network

Hosseini-Asl, M. (author), Amiri Simkooei, A. (author), Safari, A. (author)

The performance of the gravimetric geoid models is usually evaluated by comparison of geoid heights with the GNSS/levelling derived geoid. But the GNSS/levelling network can be infected by significant systematic biases and random errors, especially in large and uneven areas. This contribution addresses the challenging problem of the corrector...

journal article 2022

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Function-Based Troposphere Tomography Technique for Optimal Downscaling of Precipitation

Haji-Aghajany, Saeid (author), Amerian, Yazdan (author), Amiri Simkooei, A. (author)

Precipitation is an important meteorological indicator that has a direct and significant impact on ecology, agriculture, hydrology, and other vital areas of human health and life. It is therefore essential to monitor variations of this parameter at a global and local scale. To monitor and predict long-term changes in climate elements, Global...

journal article 2022

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Combination of regional and global geoid models at continental scale: application to Iranian geoid

Hosseini-Asl, Mahin (author), Amiri Simkooei, A. (author), Safari, Abdolreza (author)

High precision geoid determination is a challenging task at the national scale. Many efforts have been conducted to determine precise geoid, locally or globally. Geoid models have different precision depending on the type of information and the strategy employed when calculating the models. This contribution addresses the challenging problem...

journal article 2021

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On the performance of equiangular mascon solution in GRACE-like missions

Abedini, Abbas (author), Keller, Wolfgang (author), Amiri Simkooei, A. (author)

Mass concentration (mascon) solutions for GRACE (Gravity Recovery and Climate Experiment) data are widely used in various regional-to-global mass change studies. The current advances in the mascon solution have mainly concentrated on improving the spatial resolution of the solution, enhancing the applied least-squares regularization, and the...

journal article 2021

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Linking the morphology and ecology of subtidal soft-bottom marine benthic habitats: A novel multiscale approach

Mestdagh, S.M.F. (author), Amiri Simkooei, A. (author), van der Reijden, Karin J. (author), Koop, L. (author), O'Flynn, Sarah (author), Snellen, M. (author), Van Sluis, Christiaan (author), Govers, Laura L. (author), Simons, D.G. (author), Herman, P.M.J. (author), Olff, Han (author), Ysebaert, Tom (author)

High-resolution surveying techniques of subtidal soft-bottom seafloor habitats show higher small-scale variation in topography and sediment type than previously thought, but the ecological relevance of this variation remains unclear. In addition, high-resolution surveys of benthic fauna show a large spatial variability in community...

journal article 2020

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Modeling and prediction of regular ionospheric variations and deterministic anomalies

Rajabi, Mahmoud (author), Amiri Simkooei, A. (author), Nahavandchi, Hossein (author), Nafisi, Vahab (author)

Knowledge on the ionospheric total electron content (TEC) and its prediction are of great practical importance and engineering relevance in many scientific disciplines. We investigate regular ionospheric anomalies and TEC prediction by applying the least squares harmonic estimation (LS-HE) technique to a 15 year time series of the vertical...

journal article 2020

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Experimental design and stochastic modeling of hydrodynamic wave propagation within cavities for wind tunnel acoustic measurements

VanDercreek, Colin (author), Amiri Simkooei, A. (author), Snellen, M. (author), Ragni, D. (author)

This study investigates how embedding microphones in different cavity geometries along the wall of a wind tunnel reduces the measured turbulent boundary layer pressure fluctuations. The effect of these cavities on the measured signal-to-noise ratio of an acoustic source with flow present was also quantified. Twelve cavity geometries defined...

journal article 2019