Hossein Nahavandchi
About
Hossein Nahavandchi is a professor of geodesy. His research interest is Earth monitoring/climate change using satellite (Gravimetry/Altimetry/GPS) data.
Biography: Hossein Nahavandchi holds a PhD degree (1998) from Royal Institute of Technology in Stockholm. His primary research interest is satellite Gravimetry, Altimetry and GPS. He has been lecturing in the Geomatics and Geodesy fields since 1990. Hossein’s career includes being a member of staff at Isfahan University (as Senior Lecturer and Head of Department), Royal Institute of Technology in Stockholm (as Research Associate), Tehran University (as Assistant Professor), and Norwegian University of Science and Technology (as Associate Professor and Professor). He also worked for Iranian National Mapping Authority and National Cartographic Center (NCC) in several functions. He has been Vice-Dean, Dean, and the Rector of the College of Engineering, Division Director, Chair of the Borad and Board member of Research and Planning Division, and Education Department in Iran. His research projects and other activities in Civil Engineering have attracted more than 120 million NOK to the university sector since 1991. They have also resulted in a strong international network. Over 155 publications and presentations are the results of his research projects.
My Research/Teaching Interests:
Current Research: Monitoring Ocean Microplastics using GPS Signals
We use spaceborne observations from a novel remote sensing technique. The technique utilizes reflected signals of Global Navigation Satellite Systems (GNSS) and is called GNSS-Reflectometry (GNSS-R). The project aims to provide a regularly updated worldwide map of microplastics distribution on the ocean surface. The observations used in the analysis are collected using bistatic sensors onboard the NASA CYGNSS mission over the equatorial and part of the mid-latitudes regions. More than four years of GNSS-R observations are used so far. An overall verification of the results is performed using three available global microplastics models. The overall microplastic concentration map produced from GNSS-R observations shows a noticeably good agreement with the models. The promising results suggest that the GNSS-R technique can be an effective geodetic tool for the constant monitoring of microplastics on the ocean surface.
Current Research: GNSS Remote Sensing of the Arctic and Ocean using Spaceborne Reflectometry (Joint project of NTNU with GFZ)
Remote sensing using the signals of Global Navigation Satellite System (GNSS) is an established method providing a new source of observations for the study of the Earth and its atmosphere. GNSS Reflectometry (GNSS-R), a novel Earth observation technique, exploits the reflected GNSS signals from the land or water bodies to retrieve information about different geophysical parameters. This technique, in ground-based, air- or spaceborne configuration, has been widely used and still is being pursued for a variety of applications over land, ocean and ice. Different processing approaches could be used or developed to retrieve unprecedented high spatiotemporal resolution scatterometric or altimetric measurements from the reflectometry observations.
Several GNSS-R sensors onboard small satellite missions have already demonstrated the feasibility and competence of this technique. Although NASA CYGNSS (CYclone GNSS) mission currently provides GNSS-R data stream over tropical regions, the higher latitude regions as well as Polar waters are yet to be covered.
The joint project of Norwegian university of science and technology (NTNU) with GFZ will investigate the theory and design of an Earth remote sensing sensor onboard small satellites capable of measuring the oceanographic parameters related to altimetry in Norwegian and Polar waters. The project exploits GNSS-R (Global Navigation Satellite System - Reflectometry) concept which allows to use a relatively cost-efficient low-power passive sensor in a compact payload onboard future NTNU SmallSats.
The project provides required information about the methodology and instrumentation of an observing system with different geophysical parameters of interest such as sea ice thickness, sea surface height and wave height. The outcome will be implemented in the NTNU SmallSats and will be used operationally in an integrated maritime/Arctic observation network. It is foreseen to use in-situ measurements acquired by autonomous unmanned vehicle systems for calibration and enhancement of the GNSS-R products. The ultimate goal is to integrate the designed GNSS-R sensor in an integrated observation network to provide a high spatiotemporal resolution monitoring of the arctic and oceans, as the key components of the Earth’s climate system.
Left: Integrated Arctic and ocean observation network consisting of foreseen GNSS-R sensor onboard a SmallSat assisted and validated by low-altitude unmanned aerial vehicles (UAVs) and unmanned surface vehicles (USVs) for high resolution sea surface height and wave height measurements, and autonomous underwater vehicles (AUVs) for under-ice thickness measurements. Right: CYGNSS NBRCS (σ0) over two mid-latitude mesoscale ocean eddies near the south coast of Japan at two different times; in 3 dimensions in the local defined coordinate system. The evolution of the σ0 can be explained by the anomalies of sea surface temperature. The warm core of the top eddy produces higher wind speed (lower σ0) while the colder edges, by contrast, cause lower wind speeds (higher σ0).
Current Research: Assessing Groundwater depletion and dynamics using GRACE and hydrological data
Groundwater is a strategic reservoir and its shortage will cause the next global crisis. Water resource issues are often very complex and frequently require large amounts of diverse data. Collection of data by traditional means (e.g. fieldwork) can be quite difficult at times, especially in remote areas, as well as costly and resource intensive. The Gravity Recovery and Climate Experiment (GRACE) satellite gravity data can be very useful providing a cost-effective means of replacing or complimenting field data collection. GRACE satellites measure monthly changes in total terrestrial water storage by converting observed gravity anomalies into changes of equivalent water height. We use this methodology to process GRACE satellite-to-satellite tracking data to estimate groundwater depletion in the Middle East and a developed methodology to use GRACE data with enhanced spatial scale over Iran’s water basins. We remove leakage-in mass signals of the Caspian Sea and adding back the ocean model contribution that had apparently introduced a spurious positive trend over the Black Sea. To isolate the groundwater contributions, we develop a local hydrological model including soil moisture, snow, canopy, and river storage and subtract it from the GRACE total water storage results.
Groundwater changes in six different Iran's water basins using GRACE data between 2003 and 2013
Recently completed research: Quantifying land subsidence and groundwater exploitation using InSAR time series and in-situ measurements
Land subsidence due to the overdrafting of groundwater resources for industrial and agricultural purposes is a geological hazard that affects many urban and agricultural areas in the world. Several environmental effects and consequences are associated with land subsidence including damage to infrastructures and buildings, increased risk of flooding in coastal areas and accelerated erosion along Earth fissures and drainage systems. Monitoring the spatial extent and temporal evolution of surface deformation associated with fluid withdrawal is critical to mitigate hazards associated with this phenomenon. Among ground and space-based geodetic methods used for measuring land subsidence, space-borne InSAR enables a unique imaging capability for the assessment of subsidence in response to fluid extraction from subsurface reservoirs. Using SAR data from the ENVISAT, ALOS and Sentinel-1 satellites, we analyzed nearly a decade of land subsidence in the Rafsanjan region in Iran. An InSAR time-series analysis showed a persistent pattern of subsidence, with peak values found west of the city of Rafsanjan.
Average velocity maps derived from (a) ENVISAT descending, (b) ENVISAT ascending, (c) ALOS, (d) Sentinel-1 ascending, and (e) Sentinel-1 descending. The observation periods corresponding to the velocity maps are shown in (f).
We have also worked on large-scale national high-quality SAR monitoring of Norway. As an example, an interferogram over Norway has been shown in Figure below. We are working with ionospheric and tropospheric corrections.
An interfeogram over Norway using Sentinel-1 data
Standard methodology of the SAR and InSAR technique in displacement mapping has been improved. We implemented a polarimetric optimization approach on Sentinel-1 dual-polarization (VV–VH) images to improve the standard persistent scatterer interferometric synthetic aperture radar (PS-InSAR) method. Combining persistent scatterers (PS) and distributed scatterers (DS) is important for effective displacement monitoring using time-series of SAR data. However, for large stacks of SAR data, the DS analysis using existing standard algorithms becomes a time-consuming process. SqueeSAR is an approach for extracting signals from DS. We optimized this technique and evaluated the performance of our approach on 50 Sentinel-1 images acquired over Trondheim in Norway. We have made the SqueeSAR selection algorithm 98% more efficient and more robust in the case of few images. We implemented our approach in the StaMPS/MTI processing chain to deliver a time-series of combined PS and DS more efficiently than the existing StaMPS/MTI combined algorithm.
Surface displacement velocity over Trondheim with standard and optimized methods
Current Research: Quantifying water vapor contents by homogenization of GNSS time series
Quantifying water vapor, a major greenhouse gas of the atmosphere, is necessary for the climate and meteorological applications. Global Navigation Satellite System (GNSS) signals are promising measuring tools for monitoring water vapor content, but the use of GNSS products for estimating climatic trend requires homogeneity assessment in order to increase reliability and accuracy of the results. We have developed a data homogenization method based on singular spectrum analysis as a subspace-based technique. The ERA-Interim simulated data has been selected as the reference dataset. After homogenization, we used Principle Component Analysis (PCA) method to extract climate signals. We employed our developed technique over 214 permanent GNSS stations over Germany between 2010 and 2016 (7 years).
Left: A component of homogenized GNSS-derived dataset reflecting the overall classification of the climate in Germany. Right: The climatic divisions based on Köppen Climate Classification system.
Recently completed research: Ocean wave measurments using single GPS Buoy
Accurate forecasts of wave conditions are of the utmost important to all who live, work, or travel on or near ocean. To improve the wave prediction models, field measurement of ocean wave parameters is necessary. Those parameters are wave height, period and direction. We applied a methodology to derive ocean wave parameters (wave height, wave period and direction) from GPS data. The power spectrums of GPS data (among its errors) and buoy movement (excited by ocean wave) were the basis for the estimation of wave parameters. Because of the buoy movement data is in the band frequency of GPS data which signal to noise ratio (SNR) is very low, the most important point in design of high pass filter is the cut-off frequency selection of the filter. The figure below shows the power spectrum of the GPS height data in m2/Hz.
Recently completed research: Greenland Ice-mass balance from satellite gravity observations
The Gravity Recovery and Climate Experiment (GRACE) satellite mission provides temporal variations of Earth gravity field with a period of around one month. GRACE measures changes in Earth's gravity field caused by regional shifts in the Earth's mass, including ice sheets, oceans and Water stored in the soil and in underground aquifers. We used GRACE data to estimate the rate of ice mass variability over Greenland. The Figure below shows monthly ice mass changes summed over the entire Greenland ice sheet, between April 2002 and February 2010, estimated in Gigatonne grom three GRACE data sets released by GFZ (Potsdam), JPL(California) and CSR (Texas). Note that this plot shows deviation from the average ice mass over the 2002 to 2010 period. It does not mean that the ice sheet was gaining ice before 2006 but that ice mass was over the 2002 to 2010 average. The ice mass was below the 2002 to 2010 average after 2006. The trend of the best fitting straight line for CSR data is -163±20 Gigatonne per year. The results also indicate the the ice-mass loss rate has been increasing in the time period between 2002 and 2010.
Recently completed research: Ocean circulation in North Atlantic and the Arctic sea from satellite altimetry observations
The Ocean plays a key role in determining the global climate. To develop techniques for pridicting furure climate, one must undrestand the dynamics of the global ocean circulation. A viable approach to observing the global and regional ocean circulations with sufficient resolution is the use of a satellite radar altimeter to measure the Mean Sea Surface (MSS) height. Multiple radar altimetry data from ESA satellites of ENVISAT, ERS-1 and ERS-2 and NASA satellite of GFO were used to determine the NTNU MSS model. NTNU MSS model is used to derive the mean dynamic topography and the ocesn circulation as it is shown in the Figure below. This plot shows the surface currents system in the North Atlantic and the Arctic sea for the time period 1993-2007. Flow of warm water is shown as red arrow and cold water as blue arrow. The Northward flow of warm water in the North Atlantic is partly balanced by southward flow of clod water in the East Greenland. Note that the detalied surface currents are not shown in this picture.
Research Intrests
- Satellite Positioning GPS
- Satellite Gravimetry and Altimetry
- Climate Change Studies
- Polar Research
- Ocean Circulation and Transport
Teaching
- TBA4852 Interdisciplinary Teamwork
- TBA4565 Geomatics, Specialization Course
- TBA4560 Geomatics, Specialization Project
- TBA4231 Applied geomatics
- TBA4236 Theoretical geomatics
- TBA4245 Geodesy
- TBA4251 Programming in geomatics
- TTT4234 Space Technology I
- TBA4925 Geomatics, Master Thesis
- BA8200 Advanced Theory of Errors and Adjustment
- BA8202 Advanced Physical Geodesy
- BA8604 Satellite Gravimetry and Altimetry
- BA8605 Advanced Global Positioning System (GPS)
- BA8203 An integrated Earth System Approach to the Study of Ocean Climate
Research Projects
- Arctic and Antarctic Mass balance (Ice loss) from satellite gravity and satellite altimetry measurements
- Ocean Circulation and Transport Between the North Atlantic and Arctic sea (OCTAS)
- New improvments in Geoidal height modeling
- Development of a regional GPS-based model of Ionospheric for Norway
- Arctic geoid for ocean circulation, sea-ice exploration and climate change
Links:
Publications
2022
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Hoseini, Mostafa;
Nahavandchi, Hossein.
(2022)
The potential of spaceborne GNSS reflectometry for detecting ocean surface currents.
Remote Sensing of Environment.
volum 282.
Academic article
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Safdari, Zohreh;
Joodaki, Gholamreza;
Nahavandchi, Hossein.
(2022)
A Technical Note on Least Squares Mascon Fitting to GRACE Satellite Data to Estimate Total Water Storage Changes in the Middle East.
Satellite Monitoring of Water Resources in the Middle East.
Academic chapter/article/Conference paper
-
Safdari, Zohreh;
Nahavandchi, Hossein;
Joodaki, Gholamreza.
(2022)
Estimation of Groundwater Depletion in Iran’s Catchments Using Well Data.
Water.
volum 14 (1).
Academic article
2021
-
Asgarimehr, Milad;
Hoseini, Mostafa;
Semmling, Maximilian;
Ramatschi, Markus;
Camps, Adriano;
Nahavandchi, Hossein;
Haas, Rüdiger;
Wickert, Jens.
(2021)
Remote Sensing of Precipitation Using Reflected GNSS Signals: Response Analysis of Polarimetric Observations.
IEEE Transactions on Geoscience and Remote Sensing.
volum 60.
Academic article
-
Hoseini, Mostafa;
Semmling, Maximilian;
Nahavandchi, Hossein;
Rennspiess, Erik;
Ramatschi, Markus;
Haas, Rüdiger;
Strandberg, Joakim;
Wickert, Jens.
(2021)
On the Response of Polarimetric GNSS-Reflectometry to Sea Surface Roughness.
IEEE Transactions on Geoscience and Remote Sensing.
volum 59 (9).
Academic article
-
Rajabi, Mahmoud;
Hoseini, Mostafa;
Nahavandchi, Hossein;
Semmling, Maximilian;
Ramaschi, Markus;
Goli, Mehdi;
Hass, R ̈udiger;
Wickert, Jens.
(2021)
A Performance Assessment of Polarimetric GNSS-R Sea Level Monitoring in the Presence of Sea Surface Roughness.
IEEE International Geoscience and Remote Sensing Symposium proceedings.
Academic article
-
Rajabi, Mahmoud;
Hoseini, Mostafa;
Nahavandchi, Hossein;
Semmling, Maximillian;
Ramatschi, Markus;
Goli, Mehdi;
Haas, Rudiger;
Wickert, Jens.
(2021)
Polarimetric GNSS-R Sea Level Monitoring using I/Q Interference Patterns at Different Antenna Configurations and Carrier Frequencies.
IEEE Transactions on Geoscience and Remote Sensing.
volum 60.
Academic article
2020
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Hoseini, Mostafa;
Alshawaf, Fadwa;
Nahavandchi, Hossein;
Dick, Galina;
Wickert, Jens.
(2020)
Towards a zero-difference approach for homogenizing GNSS tropospheric products.
GPS Solutions.
volum 24 (8).
Academic article
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Hoseini, Mostafa;
Asgarimehr, Milad;
Zavorotny, valery;
Nahavandchi, Hossein;
Ruf, chris;
Wickert, Jens.
(2020)
First Evidence of Mesoscale Ocean Eddies Signature in GNSS Reflectometry Measurements.
Remote Sensing.
volum 12 (542).
Academic article
-
Rajabi, Mahmoud;
Amiri-Simkooei, Alireza;
Nahavandchi, Hossein;
Nafisi, Vahab.
(2020)
Modeling and Prediction of Regular Ionospheric Variations and Deterministic Anomalies.
Remote Sensing.
volum 12 (6).
Academic article
-
Rajabi, Mahmoud;
Nahavandchi, Hossein;
Hoseini, Mostafa.
(2020)
Evaluation of CYGNSS Observations for Flood Detection and Mapping during Sistan and Baluchestan Torrential Rain in 2020.
Water.
volum 12 (7).
Academic article
-
Shamshiri, Roghayeh;
Motagh, Mahdi;
Nahavandchi, Hossein;
Haghshenas, Mahmud;
Hoseini, Mostafa.
(2020)
Improving tropospheric corrections on large-scale Sentinel-1 interferogramsusing a machine learning approach for integration with GNSS-derived zenithtotal delay (ZTD).
Remote Sensing of Environment.
volum 239 (111608).
Academic article
2019
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Hoseini, Mostafa;
Asgarimehr, Milad;
Nahavandchi, Hossein;
Wickert, Jens.
(2019)
Spaceborne GNSS-R Observations of Mesoscale Ocean Eddies; Preliminary Results from Cygnss Mission.
IEEE International Geoscience and Remote Sensing Symposium proceedings.
Academic article
2018
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Shamshiri, Roghayeh;
Nahavandchi, Hossein;
Motagh, Mahdi.
(2018)
Persistent Scatterer Analysis Using Dual-Polarization Sentinel-1 Data: Contribution From VH Channel.
IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing.
volum 11 (9).
Academic article
-
Shamshiri, Roghayeh;
Nahavandchi, Hossein;
Motagh, Mahdi;
Andy, Hooper.
(2018)
Efficient Ground Surface Displacement Monitoring Using Sentinel-1 Data: Integrating Distributed Scatterers (DS) Identified Using Two-Sample t-Test with Persistent Scatterers (PS).
Remote Sensing.
volum 10 (5).
Academic article
2017
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Motagh, Mahdi;
Shamshiri, Roghayeh;
Haghshenas, Mahmud;
Wetzel, Hans-Ulrich;
Akbari, Bahman;
Nahavandchi, Hossein;
Roessner, Sigrid;
Arabi, Siavash.
(2017)
Quantifying groundwater exploitation induced subsidence in the Rafsanjan plain, southeastern Iran, using InSAR time-series and in situ measurements.
Engineering Geology.
volum 218.
Academic article
-
Nahavandchi, Hossein;
Haakonsen, Trond Arve;
Aas, Håvard.
(2017)
Accuracy investigation of UAV Photomapping.
Kart og Plan.
volum 77 (3).
Academic article
-
Shamshiri, Roghayeh;
Nahavandchi, Hossein;
Joodaki, Gholamreza.
(2017)
Seasonal variation analysis of Greenland ice mass time-series.
Acta Geodaetica et Geophysica Hungarica.
volum 53 (1).
Academic article
2016
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Shamshiri, Roghayeh;
Nahavandchi, Hossein;
Motagh, Mahdi.
(2016)
Deformation analysis of the Trondheim city from SAR Interferometry.
Proceedings Living Planet Symposium 2016.
Academic chapter/article/Conference paper
-
Shamshiri, Roghayeh;
Nahavandchi, Hossein;
Motagh, Mahdi.
(2016)
Deformation analysis of the Trondheim city from SAR Interferometry.
ESA SP.
Academic article
-
Shamshiri, Roghayeh;
Nahavandchi, Hossein;
Motagh, Mahdi;
Haghshenas, Mahmud.
(2016)
Multi-sensor InSAR analysis of surface displacement over coastal urban city of Trondheim.
Procedia Computer Science.
volum 100.
Academic article
2015
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Nahavandchi, Hossein;
Joodaki, Gholamreza;
Schwartz, Vegar.
(2015)
GRACE-derived ice-mass loss spread over Greenland.
Journal of Geodetic Science.
volum 5 (1).
Academic article
-
Nahavandchi, Hossein;
Skogseth, Terje.
(2015)
Klimaovervåking med satellitter.
Byggeindustrien.
Article
2013
-
Joodaki, Gholamreza;
Nahavandchi, Hossein;
Cheng, Kevin.
(2013)
Ocean Wave Measurement Using GPS Buoys.
Journal of Geodetic Science.
volum 3 (3).
Academic article
-
Joodaki, Gholamreza;
Nahavandchi, Hossein;
Ghazavi, Kourosh.
(2013)
Steric sea level changes from ENVISAT and GRACE in the Nordic Seas.
ESA SP.
Academic article
-
Nahavandchi, Hossein;
Skjeset, Lars.
(2013)
Geoid-type surface determination using a gravimetric quasigeoid model and GNSS/leveling data- A case study in eastern Norway.
Kart og Plan.
volum 73.
Academic article
2012
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Joodaki, Gholamreza;
Nahavandchi, Hossein.
(2012)
Mass balance and mass loss acceleration of the Greenland ice sheet (2002 – 2011) from GRACE gravity data.
Journal of Geodetic Science.
volum 2 (2).
Academic article
-
Joodaki, Gholamreza;
Nahavandchi, Hossein.
(2012)
Mass loss of the Greenland ice sheet from GRACE time-variable gravity measurements.
Studia Geophysica et Geodaetica.
volum 56 (1).
Academic article
-
Nahavandchi, Hossein;
Joodaki, Gholamreza.
(2012)
Greenland ice-melt spread into Northwest Coast revealed by GRACE (GRACE data viser at issmeltingen på Grønland sprer seg til nordvestkysten).
Kart og Plan.
volum 72 (3).
Academic article
-
Nahavandchi, Hossein;
Mahdavipour, Hossein.
(2012)
Sammenligning av geoidens høyde utledet fra geopotensialmodellen EGM2008 med GPS/nivellementsdata i et testområde i Iran (Comparison of geoid heights from the EGM2008 geopotential model and GPS/levelling data in a study area in Iran).
Kart og Plan.
volum 72 (1).
Academic article
2011
-
Ghazavi, Kourosh;
Nahavandchi, Hossein.
(2011)
Mean Sea Surface and ocean circulation in North Atlantic and the Arctic Sea.
Journal of Geodetic Science.
volum 1 (2).
Academic article
2010
-
Joodaki, Gholamreza;
Nahavandchi, Hossein.
(2010)
Greenland mass balance estimation from satellite gravity measurements.
ESA SP.
Academic article
-
Nahavandchi, Hossein;
Joodaki, Gholamreza.
(2010)
CORRELATION ANALYSIS OF MULTIPATH EFFECTS IN GPS-CODE AND CARRIER PHASE OBSERVATIONS.
Survey Review.
volum 42 (316).
Academic article
2008
-
Nahavandchi, Hossein;
Soltanpour, Ali.
(2008)
Local ionospheric modelling of GPS code and carrier phase observations.
Survey Review.
volum 40 (309).
Academic article
-
Omang, Ove Christian Dahl;
Hunegnaw, Addisu;
Solheim, Dag;
Lysaker, Dagny;
Ghazavi, Kourosh;
Nahavandchi, Hossein.
(2008)
Updated OCTAS geoid in the northern North Atlantic - OCTAS07.
International Association of Geodesy Symposia.
volum 133 (2).
Academic article
2007
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Ghazavi, Kourosh;
Nahavandchi, Hossein;
Omang, Ove Christian Dahl;
Solheim, Dag;
Soltanpour, Ali;
Shum, C.K.;
Yi, Yochan;
Lysaker, Dagny;
Pettersen, Bjørn Ragnvald;
Drange, Helge;
Johannessen, Johnny;
Gidskehaug, Arne.
(2007)
The OCTAS06-North Atlantic/Arctic ocean mean sea surface model.
Geophysical Research Abstracts.
volum 9.
Abstract
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Ghazavi, Kourosh;
Nahavandchi, Hossein;
Omang, Ove Christian Dahl;
Solheim, Dag;
Soltanpour, Ali;
Shum, C.K.;
Yi, Yochan;
Lysaker, Dagny;
Pettersen, Bjørn Ragnvald;
Drange, Helge;
Johannessen, Johnny;
Gidskehaug, Arne.
(2007)
OCTAS with a focus on the importance of a high precision mean sea surface.
Geophysical Research Abstracts.
volum 9.
Abstract
-
Solheim, Dag;
Omang, Ove Christian Dahl;
Hunegnaw, Addisu;
Drange, Helge;
Johannessen, Johnny;
siegismund, Frank;
Nahavandchi, Hossein;
Ghazavi, Kourosh;
Pettersen, Bjørn Ragnvald;
Lysaker, Dagny;
Gidskehaug, Arne;
Plag, Hans-Peter.
(2007)
The OCTAS poject, The geoid, the mean sea surface and the mean dynamic topography.
Proceedings of the 3rd International GOCE User Workshop.
Academic chapter/article/Conference paper
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Solheim, Dag;
Omang, Ove Christian Dahl;
Hunegnaw, Addisu;
Soltanpour, Ali;
Drange, Helge;
Johannessen, Johnny;
Siegismund, Frank;
Nahavandchi, Hossein;
Ghazavi, Kourosh;
Pettersen, Bjørn Ragnvald;
Lysaker, Dagny;
Gidskehaug, Arne;
Plag, Hans-Peter.
(2007)
The OCTAS project, the interrelationship between the geoid, the mean sea surface and the mean dynamic topography.
Geophysical Research Abstracts.
volum 9.
Abstract
-
Soltanpour, Ali;
Solheim, Dag;
Omang, Ove Christian Dahl;
Nahavandchi, Hossein;
Ghazavi, Kourosh;
Pettersen, Bjørn Ragnvald;
Lysaker, Dagny;
Drange, Helge;
Johannessen, Johnny;
Gidskehaug, Arne;
Plag, Hans-Peter.
(2007)
Assessment and Validation of the geoid, MSS and MDT models in the OCTAS project.
Geophysical Research Abstracts.
volum 9.
Abstract
-
Ghazavi, Kourosh;
Nahavandchi, Hossein;
Omang, Ove Christian Dahl;
Solheim, Dag;
Soltanpour, Ali;
Shum, C.K.;
Yi, Yochan;
Lysaker, Dagny;
Pettersen, Bjørn Ragnvald;
Drange, Helge;
Johannessen, Johnny;
Gidskehaug, Arne.
(2007)
The OCTAS07- North Atlantic/Arctic ocean mean sea surface model based on a wavelet adjustment of multiple satellite altimetry data.
Geophysical Research Abstracts.
volum 9.
Abstract
-
Nahavandchi, Hossein;
Soltanpour, Ali.
(2007)
Different Gravimetric Geoid Models over Iran with and without Terrestrial Gravity Data.
General Command of Mapping.
Academic article
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Omang, Ove Christian Dahl;
Solheim, Dag;
Hunegnaw, Addisu;
Lysaker, Dagny Iren;
Ghazavi, K;
Nahavandchi, Hossein.
(2007)
OCTAS with a focus on the importance of a high accuracy geoid.
Gravity Field of the Earth, Proceedings of the 1st International Symposium of the International Gravity Field Service.
Academic chapter/article/Conference paper
-
Omang, Ove Christian Dahl;
Solheim, Dag;
Hunegnaw, Addisu;
Lysaker, Dagny;
Ghazavi, Kourosh;
Nahavandchi, Hossein.
(2007)
Ocean Circulation and Transport Between North Atlantic and the Arctic Sea with a focus on the importance of a high accuracy geoid model.
General Command of Mapping.
Academic article
-
Omang, Ove Christian Dahl;
Solheim, Dag;
Hunegnaw, Addisu;
Lysaker, Dagny;
Ghazavi, Kourosh;
Nahavandchi, Hossein.
(2007)
Updated OCTAS geoid – OCTAS07.
Geophysical Research Abstracts.
volum 9.
Abstract
-
Soltanpour, Ali;
Nahavandchi, Hossein;
Ghazavi, Kourosh.
(2007)
Recovery of marine gravity anomalies from ERS1, ERS2 and ENVISAT satellite altimetry data for geoid computations over Norway.
Studia Geophysica et Geodaetica.
volum 51 (3).
Academic article
2006
-
Nahavandchi, Hossein.
(2006)
HIGH-RESOLUTION GEOID DETERMINATION- IRanian Gravimetric Geoid 2005 (IRGG05).
2006.
Report
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Nahavandchi, Hossein;
Soltanpour, Ali.
(2006)
Improved determination of heights using a conversion surface by combining gravimetric quasi-geoid/geoid and GPS-levelling height differences.
Studia Geophysica et Geodaetica.
volum 50 (2).
Academic article
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Soltanpour, Ali;
Nahavandchi, Hossein.
(2006)
A new high-resolution geoid for Iran with emphasise on different modification procedures and new GRACE geopotential model.
Geophysical Research Abstracts.
volum 8.
Abstract
-
Soltanpour, Ali;
Nahavandchi, Hossein;
Featherstone, Will.
(2006)
Geoid-type surface determination using wavelet-based combination of gravimetric quasi/geoid and GPS-levelling data.
Geophysical Research Abstracts.
volum 8.
Abstract
-
Soltanpour, Ali;
Nahavandchi, Hossein;
Featherstone, Will.
(2006)
The Use of Second-generation Wavelets to Combine a Gravimetric Quasigeoid Model with GPS-levelling Data.
Journal of Geodesy.
volum 80 (2).
Academic article
-
Soltanpour, Ali;
Nahavandchi, Hossein;
Ghazavi, Kourosh.
(2006)
Recovery of marine gravity anomaly from ERS2 and ENVISAT data and its contribution to the geoid of Norway.
Geophysical Research Abstracts.
volum 8.
Abstract
2005
-
Nyrnes, Erik;
Torkildsen, Torgeir;
Nahavandchi, Hossein.
(2005)
Detection of Gross Errors in Wellbore Directional Surveying for Petroleum Production with emphasis on Reliability Analyses.
Kart og Plan.
volum 65 (2).
Academic article
2004
-
Nahavandchi, Hossein.
(2004)
The Quest for a Precise Geoidal Height Model.
Kart og Plan.
volum 64 (1).
Academic article
-
Nahavandchi, Hossein.
(2004)
The direct effect and downward continuation correction of atmospheric masses in gravimetric geoid determination.
Bollettino di Geodesia e Scienze Affini.
volum 63 (1).
Academic article
-
Nahavandchi, Hossein;
Soltanpour, Ali;
Nyrnes, Erik.
(2004)
A New Gravimetric Geoidal Height Model over Norway Computed by the Least-Squares Modification Parameters.
Gravity, Geoid, and Space Missions.
Other
-
Nahavandchi, Hossein.
(2004)
A new strategy for the atmospheric gravity effect in gravimetric geoid determination.
Journal of Geodesy.
volum 77.
Academic article
2003
-
Nahavandchi, Hossein.
(2003)
A Comparison of the classical and recent formulae of handling the effects of close and distant topographic masses in gravimetric geoid computations.
Newton's Bulletin.
Academic article
-
Nahavandchi, Hossein.
(2003)
Corrections to "Two different methods of geoidal height determinations using a spherical harmonic representation of the geopotential, topographic corrections and the height anomaly-geoidal height difference".
Journal of Geodesy.
volum 76 (11-12).
Errata
-
Nahavandchi, Hossein.
(2003)
Use of global geopotential models for comparison of gravimetric geoid estimators by the modification of Stoke's formula.
Bollettino di Geodesia e Scienze Affini.
volum 62 (2).
Academic article
2002
-
Nahavandchi, Hossein.
(2002)
Two different methods of geoidal height determinations using a spherical harmonic representation of the geopotential, topographic corrections and the height anomaly-geoidal height difference.
Journal of Geodesy.
volum 76 (6-7).
Academic article
2001
-
Nahavandchi, Hossein.
(2001)
Physical Geodesy.
2001.
Compendium
-
Nahavandchi, Hossein;
Sjöberg, Lars Erik.
(2001)
Precise geoid determination over Sweden using the Stokes-Helmert method and improved topographic corrections.
Journal of Geodesy.
volum 75 (2-3).
Academic article
-
Nahavandchi, Hossein;
Sjöberg, Lars Erik.
(2001)
Precise geoid determination over Sweden using the Stokes-Helmert method and improved topographic corrections.
Journal of Geodesy.
volum 75 (2/3).
Academic article
-
Nahavandchi, Hossein;
Sjöberg, Lars Erik.
(2001)
Two different views of topographical and downward-continuation corrections in the Stokes-Helmert approach to geoid computation.
Journal of Geodesy.
volum 74 (11-12).
Academic article
-
Nahavandchi, Hossein;
Sjöberg, Lars Erik.
(2001)
Two different views of topographical and downward-continuation corrections in the Stokes-Helmert approach to geoid computation.
Journal of Geodesy.
volum 74 (11/12).
Academic article
2000
-
Nahavandchi, Hossein.
(2000)
Computation of mean free-air gravity anomalies by Bjerhammar's deterministic and collocation methods over Scandinavia.
Survey Review.
volum 35 (278).
Academic article
-
Nahavandchi, Hossein.
(2000)
The direct topographical correction in gravimetric geoid determination by the Stokes-Helmert method.
Journal of Geodesy.
volum 74 (6).
Academic article
-
Sjöberg, Lars Erik;
Nahavandchi, Hossein.
(2000)
The atmospheric geoid effects in Stokes’ formula.
Geophysical Journal International.
volum 140 (1).
Academic article
1999
-
Nahavandchi, Hossein.
(1999)
Geoid terrain correction to power H (super 5) of satellite derived geopotential models.
Bollettino di Geodesia e Scienze Affini.
volum 58 (3).
Academic article
-
Nahavandchi, Hossein.
(1999)
Terrain correction computations by spherical harmonics and integral formulas.
Physics and chemistry of the earth. Part A: Solid earth and geodesy.
volum 24 (1).
Academic article
-
Sjöberg, Lars Erik;
Nahavandchi, Hossein.
(1999)
On the indirect effect in the Stokes-Helmert method of geoid determination.
Journal of Geodesy.
volum 73 (2).
Academic article
1998
-
Nahavandchi, Hossein.
(1998)
On some methods of downward continuation of mean free-air gravity anomaly.
IGeS Bulletin.
volum 8.
Academic article
-
Nahavandchi, Hossein.
(1998)
Precise Gravimetric-GPS Geoid Determination with Improved Topographic Corrections Applid over Sweden.
1998.
Doctoral dissertation
-
Nahavandchi, Hossein;
Sjöberg, Lars Erik.
(1998)
Terrain corrections to power H3 in gravimetric geoid determination.
Journal of Geodesy.
volum 72 (3).
Academic article
-
Nahavandchi, Hossein;
Sjöberg, Lars Erik.
(1998)
Unification of vertical datums by GPS and gravimetric geoid models using modified Stokes formula.
Marine Geodesy.
volum 21 (4).
Academic article
1997
-
Nahavandchi, Hossein.
(1997)
Connection of vertical datums using geoid models.
Scientific and Technical Quarterly Journal of NCC.
volum 8 (29).
Academic article
-
Nahavandchi, Hossein.
(1997)
Terrain effects in geoid determination over Iran.
Scientific and Technical Quarterly Journal of NCC.
volum 7 (28).
Academic article
-
Nahavandchi, Hossein.
(1997)
The Atmospheric Geoid effects over Iran.
Scientific and Technical Quarterly Journal of NCC.
volum 8 (29).
Academic article
1996
-
Nahavandchi, Hossein.
(1996)
Determination of Spherical Harmonics coefficients by Integral Formula and Collocation method.
Scientific and Technical Quarterly Journal of NCC.
volum 6 (27).
Academic article
1995
-
Nahavandchi, Hossein.
(1995)
External Gravity Potential of the Earth and the problem of spherical harmonics Convergency in Physical Geodesy.
Scientific and Technical Quarterly Journal of NCC.
volum 6 (23).
Academic article
1994
-
Nahavandchi, Hossein.
(1994)
Compilation of 10' by 10' mean gravity anomalies in Iran.
1994.
Master thesis
1993
-
Nahavandchi, Hossein.
(1993)
Geoid Determination with geometrical methods.
Scientific and Technical Journal of NGO.
volum 2 (6).
Academic article
Journal publications
-
Hoseini, Mostafa;
Nahavandchi, Hossein.
(2022)
The potential of spaceborne GNSS reflectometry for detecting ocean surface currents.
Remote Sensing of Environment.
volum 282.
Academic article
-
Safdari, Zohreh;
Nahavandchi, Hossein;
Joodaki, Gholamreza.
(2022)
Estimation of Groundwater Depletion in Iran’s Catchments Using Well Data.
Water.
volum 14 (1).
Academic article
-
Asgarimehr, Milad;
Hoseini, Mostafa;
Semmling, Maximilian;
Ramatschi, Markus;
Camps, Adriano;
Nahavandchi, Hossein;
Haas, Rüdiger;
Wickert, Jens.
(2021)
Remote Sensing of Precipitation Using Reflected GNSS Signals: Response Analysis of Polarimetric Observations.
IEEE Transactions on Geoscience and Remote Sensing.
volum 60.
Academic article
-
Hoseini, Mostafa;
Semmling, Maximilian;
Nahavandchi, Hossein;
Rennspiess, Erik;
Ramatschi, Markus;
Haas, Rüdiger;
Strandberg, Joakim;
Wickert, Jens.
(2021)
On the Response of Polarimetric GNSS-Reflectometry to Sea Surface Roughness.
IEEE Transactions on Geoscience and Remote Sensing.
volum 59 (9).
Academic article
-
Rajabi, Mahmoud;
Hoseini, Mostafa;
Nahavandchi, Hossein;
Semmling, Maximilian;
Ramaschi, Markus;
Goli, Mehdi;
Hass, R ̈udiger;
Wickert, Jens.
(2021)
A Performance Assessment of Polarimetric GNSS-R Sea Level Monitoring in the Presence of Sea Surface Roughness.
IEEE International Geoscience and Remote Sensing Symposium proceedings.
Academic article
-
Rajabi, Mahmoud;
Hoseini, Mostafa;
Nahavandchi, Hossein;
Semmling, Maximillian;
Ramatschi, Markus;
Goli, Mehdi;
Haas, Rudiger;
Wickert, Jens.
(2021)
Polarimetric GNSS-R Sea Level Monitoring using I/Q Interference Patterns at Different Antenna Configurations and Carrier Frequencies.
IEEE Transactions on Geoscience and Remote Sensing.
volum 60.
Academic article
-
Hoseini, Mostafa;
Alshawaf, Fadwa;
Nahavandchi, Hossein;
Dick, Galina;
Wickert, Jens.
(2020)
Towards a zero-difference approach for homogenizing GNSS tropospheric products.
GPS Solutions.
volum 24 (8).
Academic article
-
Hoseini, Mostafa;
Asgarimehr, Milad;
Zavorotny, valery;
Nahavandchi, Hossein;
Ruf, chris;
Wickert, Jens.
(2020)
First Evidence of Mesoscale Ocean Eddies Signature in GNSS Reflectometry Measurements.
Remote Sensing.
volum 12 (542).
Academic article
-
Rajabi, Mahmoud;
Amiri-Simkooei, Alireza;
Nahavandchi, Hossein;
Nafisi, Vahab.
(2020)
Modeling and Prediction of Regular Ionospheric Variations and Deterministic Anomalies.
Remote Sensing.
volum 12 (6).
Academic article
-
Rajabi, Mahmoud;
Nahavandchi, Hossein;
Hoseini, Mostafa.
(2020)
Evaluation of CYGNSS Observations for Flood Detection and Mapping during Sistan and Baluchestan Torrential Rain in 2020.
Water.
volum 12 (7).
Academic article
-
Shamshiri, Roghayeh;
Motagh, Mahdi;
Nahavandchi, Hossein;
Haghshenas, Mahmud;
Hoseini, Mostafa.
(2020)
Improving tropospheric corrections on large-scale Sentinel-1 interferogramsusing a machine learning approach for integration with GNSS-derived zenithtotal delay (ZTD).
Remote Sensing of Environment.
volum 239 (111608).
Academic article
-
Hoseini, Mostafa;
Asgarimehr, Milad;
Nahavandchi, Hossein;
Wickert, Jens.
(2019)
Spaceborne GNSS-R Observations of Mesoscale Ocean Eddies; Preliminary Results from Cygnss Mission.
IEEE International Geoscience and Remote Sensing Symposium proceedings.
Academic article
-
Shamshiri, Roghayeh;
Nahavandchi, Hossein;
Motagh, Mahdi.
(2018)
Persistent Scatterer Analysis Using Dual-Polarization Sentinel-1 Data: Contribution From VH Channel.
IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing.
volum 11 (9).
Academic article
-
Shamshiri, Roghayeh;
Nahavandchi, Hossein;
Motagh, Mahdi;
Andy, Hooper.
(2018)
Efficient Ground Surface Displacement Monitoring Using Sentinel-1 Data: Integrating Distributed Scatterers (DS) Identified Using Two-Sample t-Test with Persistent Scatterers (PS).
Remote Sensing.
volum 10 (5).
Academic article
-
Motagh, Mahdi;
Shamshiri, Roghayeh;
Haghshenas, Mahmud;
Wetzel, Hans-Ulrich;
Akbari, Bahman;
Nahavandchi, Hossein;
Roessner, Sigrid;
Arabi, Siavash.
(2017)
Quantifying groundwater exploitation induced subsidence in the Rafsanjan plain, southeastern Iran, using InSAR time-series and in situ measurements.
Engineering Geology.
volum 218.
Academic article
-
Nahavandchi, Hossein;
Haakonsen, Trond Arve;
Aas, Håvard.
(2017)
Accuracy investigation of UAV Photomapping.
Kart og Plan.
volum 77 (3).
Academic article
-
Shamshiri, Roghayeh;
Nahavandchi, Hossein;
Joodaki, Gholamreza.
(2017)
Seasonal variation analysis of Greenland ice mass time-series.
Acta Geodaetica et Geophysica Hungarica.
volum 53 (1).
Academic article
-
Shamshiri, Roghayeh;
Nahavandchi, Hossein;
Motagh, Mahdi.
(2016)
Deformation analysis of the Trondheim city from SAR Interferometry.
ESA SP.
Academic article
-
Shamshiri, Roghayeh;
Nahavandchi, Hossein;
Motagh, Mahdi;
Haghshenas, Mahmud.
(2016)
Multi-sensor InSAR analysis of surface displacement over coastal urban city of Trondheim.
Procedia Computer Science.
volum 100.
Academic article
-
Nahavandchi, Hossein;
Joodaki, Gholamreza;
Schwartz, Vegar.
(2015)
GRACE-derived ice-mass loss spread over Greenland.
Journal of Geodetic Science.
volum 5 (1).
Academic article
-
Nahavandchi, Hossein;
Skogseth, Terje.
(2015)
Klimaovervåking med satellitter.
Byggeindustrien.
Article
-
Joodaki, Gholamreza;
Nahavandchi, Hossein;
Cheng, Kevin.
(2013)
Ocean Wave Measurement Using GPS Buoys.
Journal of Geodetic Science.
volum 3 (3).
Academic article
-
Joodaki, Gholamreza;
Nahavandchi, Hossein;
Ghazavi, Kourosh.
(2013)
Steric sea level changes from ENVISAT and GRACE in the Nordic Seas.
ESA SP.
Academic article
-
Nahavandchi, Hossein;
Skjeset, Lars.
(2013)
Geoid-type surface determination using a gravimetric quasigeoid model and GNSS/leveling data- A case study in eastern Norway.
Kart og Plan.
volum 73.
Academic article
-
Joodaki, Gholamreza;
Nahavandchi, Hossein.
(2012)
Mass balance and mass loss acceleration of the Greenland ice sheet (2002 – 2011) from GRACE gravity data.
Journal of Geodetic Science.
volum 2 (2).
Academic article
-
Joodaki, Gholamreza;
Nahavandchi, Hossein.
(2012)
Mass loss of the Greenland ice sheet from GRACE time-variable gravity measurements.
Studia Geophysica et Geodaetica.
volum 56 (1).
Academic article
-
Nahavandchi, Hossein;
Joodaki, Gholamreza.
(2012)
Greenland ice-melt spread into Northwest Coast revealed by GRACE (GRACE data viser at issmeltingen på Grønland sprer seg til nordvestkysten).
Kart og Plan.
volum 72 (3).
Academic article
-
Nahavandchi, Hossein;
Mahdavipour, Hossein.
(2012)
Sammenligning av geoidens høyde utledet fra geopotensialmodellen EGM2008 med GPS/nivellementsdata i et testområde i Iran (Comparison of geoid heights from the EGM2008 geopotential model and GPS/levelling data in a study area in Iran).
Kart og Plan.
volum 72 (1).
Academic article
-
Ghazavi, Kourosh;
Nahavandchi, Hossein.
(2011)
Mean Sea Surface and ocean circulation in North Atlantic and the Arctic Sea.
Journal of Geodetic Science.
volum 1 (2).
Academic article
-
Joodaki, Gholamreza;
Nahavandchi, Hossein.
(2010)
Greenland mass balance estimation from satellite gravity measurements.
ESA SP.
Academic article
-
Nahavandchi, Hossein;
Joodaki, Gholamreza.
(2010)
CORRELATION ANALYSIS OF MULTIPATH EFFECTS IN GPS-CODE AND CARRIER PHASE OBSERVATIONS.
Survey Review.
volum 42 (316).
Academic article
-
Nahavandchi, Hossein;
Soltanpour, Ali.
(2008)
Local ionospheric modelling of GPS code and carrier phase observations.
Survey Review.
volum 40 (309).
Academic article
-
Omang, Ove Christian Dahl;
Hunegnaw, Addisu;
Solheim, Dag;
Lysaker, Dagny;
Ghazavi, Kourosh;
Nahavandchi, Hossein.
(2008)
Updated OCTAS geoid in the northern North Atlantic - OCTAS07.
International Association of Geodesy Symposia.
volum 133 (2).
Academic article
-
Ghazavi, Kourosh;
Nahavandchi, Hossein;
Omang, Ove Christian Dahl;
Solheim, Dag;
Soltanpour, Ali;
Shum, C.K.;
Yi, Yochan;
Lysaker, Dagny;
Pettersen, Bjørn Ragnvald;
Drange, Helge;
Johannessen, Johnny;
Gidskehaug, Arne.
(2007)
The OCTAS06-North Atlantic/Arctic ocean mean sea surface model.
Geophysical Research Abstracts.
volum 9.
Abstract
-
Ghazavi, Kourosh;
Nahavandchi, Hossein;
Omang, Ove Christian Dahl;
Solheim, Dag;
Soltanpour, Ali;
Shum, C.K.;
Yi, Yochan;
Lysaker, Dagny;
Pettersen, Bjørn Ragnvald;
Drange, Helge;
Johannessen, Johnny;
Gidskehaug, Arne.
(2007)
OCTAS with a focus on the importance of a high precision mean sea surface.
Geophysical Research Abstracts.
volum 9.
Abstract
-
Solheim, Dag;
Omang, Ove Christian Dahl;
Hunegnaw, Addisu;
Soltanpour, Ali;
Drange, Helge;
Johannessen, Johnny;
Siegismund, Frank;
Nahavandchi, Hossein;
Ghazavi, Kourosh;
Pettersen, Bjørn Ragnvald;
Lysaker, Dagny;
Gidskehaug, Arne;
Plag, Hans-Peter.
(2007)
The OCTAS project, the interrelationship between the geoid, the mean sea surface and the mean dynamic topography.
Geophysical Research Abstracts.
volum 9.
Abstract
-
Soltanpour, Ali;
Solheim, Dag;
Omang, Ove Christian Dahl;
Nahavandchi, Hossein;
Ghazavi, Kourosh;
Pettersen, Bjørn Ragnvald;
Lysaker, Dagny;
Drange, Helge;
Johannessen, Johnny;
Gidskehaug, Arne;
Plag, Hans-Peter.
(2007)
Assessment and Validation of the geoid, MSS and MDT models in the OCTAS project.
Geophysical Research Abstracts.
volum 9.
Abstract
-
Ghazavi, Kourosh;
Nahavandchi, Hossein;
Omang, Ove Christian Dahl;
Solheim, Dag;
Soltanpour, Ali;
Shum, C.K.;
Yi, Yochan;
Lysaker, Dagny;
Pettersen, Bjørn Ragnvald;
Drange, Helge;
Johannessen, Johnny;
Gidskehaug, Arne.
(2007)
The OCTAS07- North Atlantic/Arctic ocean mean sea surface model based on a wavelet adjustment of multiple satellite altimetry data.
Geophysical Research Abstracts.
volum 9.
Abstract
-
Nahavandchi, Hossein;
Soltanpour, Ali.
(2007)
Different Gravimetric Geoid Models over Iran with and without Terrestrial Gravity Data.
General Command of Mapping.
Academic article
-
Omang, Ove Christian Dahl;
Solheim, Dag;
Hunegnaw, Addisu;
Lysaker, Dagny;
Ghazavi, Kourosh;
Nahavandchi, Hossein.
(2007)
Ocean Circulation and Transport Between North Atlantic and the Arctic Sea with a focus on the importance of a high accuracy geoid model.
General Command of Mapping.
Academic article
-
Omang, Ove Christian Dahl;
Solheim, Dag;
Hunegnaw, Addisu;
Lysaker, Dagny;
Ghazavi, Kourosh;
Nahavandchi, Hossein.
(2007)
Updated OCTAS geoid – OCTAS07.
Geophysical Research Abstracts.
volum 9.
Abstract
-
Soltanpour, Ali;
Nahavandchi, Hossein;
Ghazavi, Kourosh.
(2007)
Recovery of marine gravity anomalies from ERS1, ERS2 and ENVISAT satellite altimetry data for geoid computations over Norway.
Studia Geophysica et Geodaetica.
volum 51 (3).
Academic article
-
Nahavandchi, Hossein;
Soltanpour, Ali.
(2006)
Improved determination of heights using a conversion surface by combining gravimetric quasi-geoid/geoid and GPS-levelling height differences.
Studia Geophysica et Geodaetica.
volum 50 (2).
Academic article
-
Soltanpour, Ali;
Nahavandchi, Hossein.
(2006)
A new high-resolution geoid for Iran with emphasise on different modification procedures and new GRACE geopotential model.
Geophysical Research Abstracts.
volum 8.
Abstract
-
Soltanpour, Ali;
Nahavandchi, Hossein;
Featherstone, Will.
(2006)
Geoid-type surface determination using wavelet-based combination of gravimetric quasi/geoid and GPS-levelling data.
Geophysical Research Abstracts.
volum 8.
Abstract
-
Soltanpour, Ali;
Nahavandchi, Hossein;
Featherstone, Will.
(2006)
The Use of Second-generation Wavelets to Combine a Gravimetric Quasigeoid Model with GPS-levelling Data.
Journal of Geodesy.
volum 80 (2).
Academic article
-
Soltanpour, Ali;
Nahavandchi, Hossein;
Ghazavi, Kourosh.
(2006)
Recovery of marine gravity anomaly from ERS2 and ENVISAT data and its contribution to the geoid of Norway.
Geophysical Research Abstracts.
volum 8.
Abstract
-
Nyrnes, Erik;
Torkildsen, Torgeir;
Nahavandchi, Hossein.
(2005)
Detection of Gross Errors in Wellbore Directional Surveying for Petroleum Production with emphasis on Reliability Analyses.
Kart og Plan.
volum 65 (2).
Academic article
-
Nahavandchi, Hossein.
(2004)
The Quest for a Precise Geoidal Height Model.
Kart og Plan.
volum 64 (1).
Academic article
-
Nahavandchi, Hossein.
(2004)
The direct effect and downward continuation correction of atmospheric masses in gravimetric geoid determination.
Bollettino di Geodesia e Scienze Affini.
volum 63 (1).
Academic article
-
Nahavandchi, Hossein.
(2004)
A new strategy for the atmospheric gravity effect in gravimetric geoid determination.
Journal of Geodesy.
volum 77.
Academic article
-
Nahavandchi, Hossein.
(2003)
A Comparison of the classical and recent formulae of handling the effects of close and distant topographic masses in gravimetric geoid computations.
Newton's Bulletin.
Academic article
-
Nahavandchi, Hossein.
(2003)
Corrections to "Two different methods of geoidal height determinations using a spherical harmonic representation of the geopotential, topographic corrections and the height anomaly-geoidal height difference".
Journal of Geodesy.
volum 76 (11-12).
Errata
-
Nahavandchi, Hossein.
(2003)
Use of global geopotential models for comparison of gravimetric geoid estimators by the modification of Stoke's formula.
Bollettino di Geodesia e Scienze Affini.
volum 62 (2).
Academic article
-
Nahavandchi, Hossein.
(2002)
Two different methods of geoidal height determinations using a spherical harmonic representation of the geopotential, topographic corrections and the height anomaly-geoidal height difference.
Journal of Geodesy.
volum 76 (6-7).
Academic article
-
Nahavandchi, Hossein;
Sjöberg, Lars Erik.
(2001)
Precise geoid determination over Sweden using the Stokes-Helmert method and improved topographic corrections.
Journal of Geodesy.
volum 75 (2-3).
Academic article
-
Nahavandchi, Hossein;
Sjöberg, Lars Erik.
(2001)
Precise geoid determination over Sweden using the Stokes-Helmert method and improved topographic corrections.
Journal of Geodesy.
volum 75 (2/3).
Academic article
-
Nahavandchi, Hossein;
Sjöberg, Lars Erik.
(2001)
Two different views of topographical and downward-continuation corrections in the Stokes-Helmert approach to geoid computation.
Journal of Geodesy.
volum 74 (11-12).
Academic article
-
Nahavandchi, Hossein;
Sjöberg, Lars Erik.
(2001)
Two different views of topographical and downward-continuation corrections in the Stokes-Helmert approach to geoid computation.
Journal of Geodesy.
volum 74 (11/12).
Academic article
-
Nahavandchi, Hossein.
(2000)
Computation of mean free-air gravity anomalies by Bjerhammar's deterministic and collocation methods over Scandinavia.
Survey Review.
volum 35 (278).
Academic article
-
Nahavandchi, Hossein.
(2000)
The direct topographical correction in gravimetric geoid determination by the Stokes-Helmert method.
Journal of Geodesy.
volum 74 (6).
Academic article
-
Sjöberg, Lars Erik;
Nahavandchi, Hossein.
(2000)
The atmospheric geoid effects in Stokes’ formula.
Geophysical Journal International.
volum 140 (1).
Academic article
-
Nahavandchi, Hossein.
(1999)
Geoid terrain correction to power H (super 5) of satellite derived geopotential models.
Bollettino di Geodesia e Scienze Affini.
volum 58 (3).
Academic article
-
Nahavandchi, Hossein.
(1999)
Terrain correction computations by spherical harmonics and integral formulas.
Physics and chemistry of the earth. Part A: Solid earth and geodesy.
volum 24 (1).
Academic article
-
Sjöberg, Lars Erik;
Nahavandchi, Hossein.
(1999)
On the indirect effect in the Stokes-Helmert method of geoid determination.
Journal of Geodesy.
volum 73 (2).
Academic article
-
Nahavandchi, Hossein.
(1998)
On some methods of downward continuation of mean free-air gravity anomaly.
IGeS Bulletin.
volum 8.
Academic article
-
Nahavandchi, Hossein;
Sjöberg, Lars Erik.
(1998)
Terrain corrections to power H3 in gravimetric geoid determination.
Journal of Geodesy.
volum 72 (3).
Academic article
-
Nahavandchi, Hossein;
Sjöberg, Lars Erik.
(1998)
Unification of vertical datums by GPS and gravimetric geoid models using modified Stokes formula.
Marine Geodesy.
volum 21 (4).
Academic article
-
Nahavandchi, Hossein.
(1997)
Connection of vertical datums using geoid models.
Scientific and Technical Quarterly Journal of NCC.
volum 8 (29).
Academic article
-
Nahavandchi, Hossein.
(1997)
Terrain effects in geoid determination over Iran.
Scientific and Technical Quarterly Journal of NCC.
volum 7 (28).
Academic article
-
Nahavandchi, Hossein.
(1997)
The Atmospheric Geoid effects over Iran.
Scientific and Technical Quarterly Journal of NCC.
volum 8 (29).
Academic article
-
Nahavandchi, Hossein.
(1996)
Determination of Spherical Harmonics coefficients by Integral Formula and Collocation method.
Scientific and Technical Quarterly Journal of NCC.
volum 6 (27).
Academic article
-
Nahavandchi, Hossein.
(1995)
External Gravity Potential of the Earth and the problem of spherical harmonics Convergency in Physical Geodesy.
Scientific and Technical Quarterly Journal of NCC.
volum 6 (23).
Academic article
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Nahavandchi, Hossein.
(1993)
Geoid Determination with geometrical methods.
Scientific and Technical Journal of NGO.
volum 2 (6).
Academic article
Part of book/report
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Safdari, Zohreh;
Joodaki, Gholamreza;
Nahavandchi, Hossein.
(2022)
A Technical Note on Least Squares Mascon Fitting to GRACE Satellite Data to Estimate Total Water Storage Changes in the Middle East.
Satellite Monitoring of Water Resources in the Middle East.
Academic chapter/article/Conference paper
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Shamshiri, Roghayeh;
Nahavandchi, Hossein;
Motagh, Mahdi.
(2016)
Deformation analysis of the Trondheim city from SAR Interferometry.
Proceedings Living Planet Symposium 2016.
Academic chapter/article/Conference paper
-
Solheim, Dag;
Omang, Ove Christian Dahl;
Hunegnaw, Addisu;
Drange, Helge;
Johannessen, Johnny;
siegismund, Frank;
Nahavandchi, Hossein;
Ghazavi, Kourosh;
Pettersen, Bjørn Ragnvald;
Lysaker, Dagny;
Gidskehaug, Arne;
Plag, Hans-Peter.
(2007)
The OCTAS poject, The geoid, the mean sea surface and the mean dynamic topography.
Proceedings of the 3rd International GOCE User Workshop.
Academic chapter/article/Conference paper
-
Omang, Ove Christian Dahl;
Solheim, Dag;
Hunegnaw, Addisu;
Lysaker, Dagny Iren;
Ghazavi, K;
Nahavandchi, Hossein.
(2007)
OCTAS with a focus on the importance of a high accuracy geoid.
Gravity Field of the Earth, Proceedings of the 1st International Symposium of the International Gravity Field Service.
Academic chapter/article/Conference paper
-
Nahavandchi, Hossein;
Soltanpour, Ali;
Nyrnes, Erik.
(2004)
A New Gravimetric Geoidal Height Model over Norway Computed by the Least-Squares Modification Parameters.
Gravity, Geoid, and Space Missions.
Other
Report
-
Nahavandchi, Hossein.
(2006)
HIGH-RESOLUTION GEOID DETERMINATION- IRanian Gravimetric Geoid 2005 (IRGG05).
2006.
Report
-
Nahavandchi, Hossein.
(2001)
Physical Geodesy.
2001.
Compendium
-
Nahavandchi, Hossein.
(1998)
Precise Gravimetric-GPS Geoid Determination with Improved Topographic Corrections Applid over Sweden.
1998.
Doctoral dissertation
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Nahavandchi, Hossein.
(1994)
Compilation of 10' by 10' mean gravity anomalies in Iran.
1994.
Master thesis
Teaching
Courses
- TBA4236 - Theoretical Geomatics
- TBA4565 - Geomatics, Specialization Course
- TBA4245 - GPS and Geodesy
- BA8605 - Advanced Global Positioning System (GPS)
- TBA4925 - Geomatics, Master's Thesis
- BA8604 - Satellite Gravimetry and Altimetry
- BA8203 - An Integrated Earth System Approach to the Study of Ocean Climate
- BYGT2201 - Geomatics
- BA8202 - Advanced Physical Geodesy
- BA8200 - Advanced Theory of Errors and Adjustment
- TBA4231 - Applied Geomatics
- TBA4560 - Geomatics, Specialization Project
- TBA4251 - Programming in Geomatics
Media
2022
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Academic lectureMohamadi, Ardeshir; Nahavandchi, Hossein. (2022) High-accuracy GNSS positioning for urban mobility and optimal transport solutions. GEOMATIKKDAGENE 2022 . GeoForum; Sundvolden. 2022-03-29 - 2022-03-31.
2019
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PosterHoseini, Mostafa; Nahavandchi, Hossein; Asgarimehr, Milad; Wickert, Jens. (2019) Impact of sea surface temperature on GNSS-R observations over mesoscale ocean eddies: preliminary results from CYGNSS. IEEE GNSS+R 2019 . IEEE and IEEE GRRS; Benevento. 2019-05-20 - 2019-05-22.
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Academic lectureShamshiri, Roghayeh; Haghshenas, Mahmud; Hoseini, Mostafa; Modiri, Sadegh; Nahavandchi, Hossein; Motagh, Mahdi. (2019) Large-scale Sentinel-1 InSAR analysis over Norway: Influence of atmospheric water vapour distribution. ESA Living Planet Symposium . ESA; Milan. 2019-05-13 - 2019-05-17.
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PosterShamshiri, Roghayeh; Motagh, Mahdi; Nahavandchi, Hossein. (2019) A machine learning-based regression technique for prediction of tropospheric phase delay on large-scale Sentinel-1 InSAR time series. EGU General Assembly . European Geosciences Union (EGU); Vienna. 2019-04-07 - 2019-04-12.
2018
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Academic lectureHoseini, Mostafa; Alshawaf, Fadwa; Dick, Galina; Wickert, Jens; Nahavandchi, Hossein. (2018) Analysis of GNSS atmospheric time series using subspace-based techniques for climate monitoring. IX Hotine-Marussi Symposium . International Association of Geodesy (IAG); Rome. 2018-06-18 - 2018-06-22.
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PosterShamshiri, Roghayeh; Nahavandchi, Hossein; Motagh, Mahdi; Hooper, Andy. (2018) A modified SqueeSAR approach for urban displacement monitoring with Sentinel-1 data. European Geosciences Union General Assembly 2018 . European Geosciences Union; Viena. 2018-04-08 - 2018-04-13.
2016
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Academic lectureNahavandchi, Hossein. (2016) Coordinate Systems- The foundation needed for Earth-system monitoring. The 1st Conference on Geospatial Information Technology (NCGIT) . KN Toosi University of Technology; Teheran. 2016-01-18 - 2016-01-21.
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LectureNahavandchi, Hossein. (2016) Deformation analysis of urban areas using Interferometry SAR satellite data. Iran Construction Engineering Organization workshop . Iran Construction Engineering Organization-Gilan Branch; Gilan. 2016-07-09 - 2016-07-19.
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Academic lectureNahavandchi, Hossein. (2016) Infrastructure monitoring using SAR radar satellite data. Iran Construction Engineering Organization Professional Seminar . Iran Construction Engineering Organization; Rasht. 2016-07-19 - 2016-08-02.
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Academic lectureNahavandchi, Hossein; Shamshiri, Roghayeh. (2016) Infrastructure monitoring using SAR interferometry. Geodesi-og hydrografidagene . GeoForum; Stavanger. 2016-11-16 - 2016-11-17.
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PosterShamshiri, Roghayeh; Motagh, Mahdi; Nahavandchi, Hossein; Wetzel, Hans-Ulrich; Akbari, Bahman. (2016) Land subsidence monitoring in Rafsanjan plain, southeast Iran using multi-sensor InSAR data. NGU-dagen . Norges geologiske undersøkelse; Trondheim. 2016-02-04 - 2016-02-05.
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Academic lectureShamshiri, Roghayeh; Nahavandchi, Hossein; Motagh, Mahdi. (2016) Stability assessment of roads and railways in Trondheim by using TerraSAR-X. TSX/TDX TerraSAR-X Science Team Meeting . DLR German Aerospace Center; Munich. 2016-10-17 - 2016-10-20.
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Academic lectureShamshiri, Roghayeh; Nahavandchi, Hossein; Motagh, Mahdi; Haghshenas, Mahmud. (2016) Multi-sensor InSAR analysis of surface displacement over Trondheim. CENTERIS Conference- SARWatch . University of Trás-os-Montes e Alto Douro; Porto. 2016-10-05 - 2016-10-07.
2014
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Academic lectureNahavandchi, Hossein; Schwartz, Vegard; Joodaki, Gholamreza. (2014) GRACE- beregning av ismassereduksjon på Grønland. Geomatikkdagene 2014 . GeoForum; Stjørdal. 2014-04-01 - 2014-04-03.
2013
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Academic lectureNahavandchi, Hossein. (2013) Are Global Gravity Models alone Accurate Enough for Height Determination using GPS?. Geodesi- og hydrografidagene . GeoForum og Statens Kartverk; Sundvolden. 2013-11-13 - 2013-11-14.
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Academic lectureNahavandchi, Hossein. (2013) Groundwater Level Estimation from GRACE Satellite Gravity Data. Geodesi- og hydrografidagene . GeoForum og Statens Kartverk; Sundvolden. 2013-11-13 - 2013-11-14.
2012
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PosterJoodaki, Gholamreza; Nahavandchi, Hossein; Ghazavi, Kourosh. (2012) Steric Sea Level Changes Using Altimetry and Gravimetry Satellites- A Case Study over Nordic Seas. 20 Years of Progress in Radar Altimetry . European Space Agency; Venice. 2012-09-24 - 2012-09-29.
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Academic lectureNahavandchi, Hossein. (2012) Greenland Ice Mass Loss and Spread from GRACE Satellite Gravity Observations. Geodesi- og hydrografidagene . Geoforum og Statens Kartverk; Stavanger. 2012-11-07 - 2012-11-08.
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Academic lectureNahavandchi, Hossein. (2012) Ocean Wave Measurement (Wave Height, Period and Direction)Using Single GPS Buoy. Geodesi- og Hydrografidagene . Geoforum og Statens Kartverk; Stavanger. 2012-11-07 - 2012-11-08.
2010
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PosterJoodaki, Gholamreza; Nahavandchi, Hossein. (2010) Greenland mass balance estimation from satellite gravity measurements. The 2010 European Space Agency Living Planet Symposium . European Space Agency; Bergen. 2010-06-28 - 2010-07-02.
2007
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PosterGhazavi, Kourosh; Nahavandchi, Hossein; Shum, C.K.; Yi, Yochan; Omang, Ove Christian Dahl; Solheim, Dag. (2007) Altimetric mean sea surface for the North Atlantic and the Arctic Sea. International Union of Geodesy and Geophysics (IUGG) XXIV 2007 . International Union of Geodesy and Geophysics; PERUGIA. 2007-07-02 - 2007-07-13.
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InterviewNahavandchi, Hossein. (2007) Bremser forskningen. Morgenbladet [Internett]. 2007-10-12.
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PosterNahavandchi, Hossein; Shum, C.K.; Yi, Yochan; Omang, Ove Christian Dahl; Solheim, Dag. (2007) Ocean circulation with a focus on the importance of a high precision mean sea surface model. International Union of Geodesy and Geophysics (IUGG) XXIV 2007 . International Union of Geodesy and Geophysics; PERUGIA. 2007-07-02 - 2007-07-13.
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PosterOmang, Ove Christian Dahl; Solheim, Dag; Hunegnaw, Addisu; Lysaker, Dagny Iren; Ghazavi, K; Nahavandchi, Hossein. (2007) Updated OCTAS geoid - OCTAS07. European Geosciences Union General Assembly 2007 ; Wien. 2007-04-15 - 2007-04-20.
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PosterOmang, Ove Christian Dahl; Solheim, Dag; Hunegnaw, Addisu; Lysaker, Dagny; Ghazavi, Kourosh; Nahavandchi, Hossein. (2007) Updated OCTAS geoid in the northern North Atlantic - OCTAS07. International Union of Geodesy and Geophysics (IUGG) XXIV 2007 . International Union of Geodesy and Geophysics; PERUGIA. 2007-07-02 - 2007-07-13.
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PosterSolheim, Dag; Omang, Ove Christian Dahl; Hunegnaw, Addisu; Drange, Helge; Johannessen, J.A.; Siegismund, F.; Nahavandchi, Hossein; Ghazavi, K; Pettersen, Bjørn Ragnvald; Lysaker, Dagny Iren; Gidskehaug, Arne; Plag, Hans-Peter. (2007) The OCTAS project, the interrelationship between the geoid, the mean sea surface and the mean dynamic topography. European Geosciences Union, General Assembly 2007 ; Wien. 2007-04-15 - 2007-04-20.
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PosterSoltanpour, Ali; Nahavandchi, Hossein. (2007) Geoid-type surface computation for the improved determination of heights from global positioning systems. International Union of Geodesy and Geophysics (IUGG) XXIV 2007 . International Union of Geodesy and Geophysics; PERUGIA. 2007-07-02 - 2007-07-13.
2006
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PosterNahavandchi, Hossein; Soltanpour, Ali. (2006) Different Geoidal Height Models over Iran with and Without Terrestrial Gravity Data. 1st international symposium of the international gravity field service, Gravity field of the Earth . International association of Geodesy; Istanbul. 2006-08-28 - 2006-09-01.
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Academic lectureOmang, Ove Christian Dahl; Solheim, Dag; Hunegnaw, Addisu; Lysaker, Dagny; Ghazavi, Kourosh; Nahavandchi, Hossein. (2006) Ocean Circulation and Transport between the North Atlantic and Arctic Sea with a Focus on the Importance of a High Accuracy Geoid Model. 1st international Symposium of the international gravity field service, Gravity field of the Earth . International Association of Geodesy; Istanbul. 2006-08-28 - 2006-09-01.
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Academic lectureSolheim, Dag; Drange, Helge; Gidskehaug, Arne; Johannessen, Johnny; Nahavandchi, Hossein; Omang, Ove Christian Dahl; Pettersen, Bjørn Ragnvald; Plag, Hans-Peter. (2006) OCTAS: Ocean Circulation and Heat Transport between the North Atlantic and Arctic Sea. Nordic Geodetic Commission General Assembly . Nordic Geodetic Commission; Copenhagen. 2006-05-29 - 2006-06-02.
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Academic lectureSolheim, Dag; Drange, Helge; Johannessen, Johnny; Nahavandchi, Hossein; Omang, Ove Christian Dahl; Pettersen, Bjørn Ragnvald; Plag, Hans-Peter. (2006) Ocean Circulation and Transport between the North Atlantic and Arctic Sea -- status report 2006. Nordic Geodetic Commission General Assembly . Nordic Geodetic Commission; Copenhagen. 2006-05-29 - 2006-06-02.
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Academic lectureSolheim, Dag; Omang, Ove Christian Dahl; Hunegnaw, Addisu; Drange, Helge; Johannessen, Johnny; Siegismund, Frank; Nahavandchi, Hossein; Ghazavi, Kourosh; Pettersen, Bjørn Ragnvald; Lysaker, Dagny; Gidskehaug, Arne; Plag, Hans-Peter. (2006) The OCTAS project, the geoid, the mean sea surface and and the mean dynamic topography. Third International GOCE User Workshop . EUROPEAN SPACE AGENCY; Frascati. 2006-11-06 - 2006-11-08.
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Academic lectureSoltanpour, Ali; Nahavandchi, Hossein. (2006) Altimetry-derived marine gravity anomaly and its impact to the geoid of Norway. Nordic Geodetic Commission General Assembly . Nordic Geodetic Commission; Copenhagen. 2006-05-29 - 2006-06-02.
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Academic lectureSoltanpour, Ali; Nahavandchi, Hossein. (2006) Geoid and geoid-type surfaces determination in Norway. Nordic Geodetic Commission General Assembly . Nordic Geodetic Commission; Copenhagen. 2006-05-29 - 2006-06-02.
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PosterSoltanpour, Ali; Nahavandchi, Hossein. (2006) How Second-Generation Wavelet Transform Can Improve the Results from Least- Squares Collocation- a Case Study over Norway. 1st International Symposium of the International Gravity Field Service, Gravity Field of the Earth . International Association of Geodesy; Istanbul. 2006-08-28 - 2006-09-01.
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PosterSoltanpour, Ali; Nahavandchi, Hossein; Featherstone, Will. (2006) Geoid-type surface determination using wavelet-based combination of gravimetric quasi/geoid and GPS-levelling data. European Geosciences Union General Assembly 2006 . European Geosciences Union; Vienna. 2006-04-02 - 2006-04-07.
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PosterSoltanpour, Ali; Nahavandchi, Hossein; Ghazavi, Kourosh. (2006) Recovery of marine gravity anomaly from ERS2 and ENVISAT data and its contribution to the geoid of Norway. European Geosciences Union General Assembly 2006 . European Geosciences Union; Vienna. 2006-04-02 - 2006-04-07.
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Academic lectureSolheim, Dag; Omang, Ove Christian Dahl; Hunegnaw, Addisu; Drange, Helge; Johannessen, J.A.; Siegismund, F.; Nahavandchi, Hossein; Ghazavi, K; Pettersen, Bjørn Ragnvald; Lysaker, Dagny Iren; Gidskehaug, Arne; Plag, Hans-Peter. (2006) The Octas project, the geoid, the mean sea surface, and the mean dynamic topography. 3rd International GOCE User Workshop ; Roma. 2006-07-01 - 2006-07-03.
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PosterSoltanpour, Ali; Nahavandchi, Hossein. (2006) A new high-resolution geoid for Iran with emphasise on different modification procedures and new GRACE geopotential model. European Geosciences Uion General Assembly 2006 . European Geosciences Union; Vienna. 2006-04-02 - 2006-04-07.
2005
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Academic lectureNyrnes, Erik; Torkildsen, Torgeir; Nahavandchi, Hossein. (2005) Analyses of the Accuracy and Reliability of Magnetic Directional Surveys. SPE/IADC Middle East Drilling Technology Conference and Exhibition . Society of Petroleum Engineers; Dubai. 2005-09-12 - 2005-09-14.
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Academic lectureNyrnes, Erik; Torkildsen, Torgeir; Nahavandchi, Hossein. (2005) Error Properties of Magnetic Directional Surveying Data. SPWLA 46th Annual Logging Symposium . Society of Petrophysicists and Well Log Analysts (SPWLA); New Orleans, Louisiana. 2005-06-26 - 2005-06-29.
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PosterSolheim, Dag; Drange, Helge; Johannessen, Johnny; Nahavandchi, Hossein; Omang, Ove Christian Dahl; Pettersen, B.; Plag, Hans-Peter. (2005) Ocean Circulation and Transport between the North Atlantic and Arctic Sea-status report 2005. General Assembly- European Geosciences Union . European Geosciences Union; Vienna. 2005-04-24 - 2005-04-29.
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PosterSolheim, Dag; Drange, Helge; Ghazavi, K; Gidskehaug, Arne; Johannessen, J.A.; Lysaker, Dagny Iren; Nahavandchi, Hossein; Omang, Ove Christian Dahl; Pettersen, Bjørn Ragnvald; Plag, Hans-Peter; Siegismund, F.. (2005) Ocean Circulation and TRansport between the North Atlantic and Arctic Sea - status report 2005. European Geosciences Union 2005 ; Wien, Østerrike. 2005-04-24 - 2005-04-29.
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PosterSolheim, Dag; Drange, Helge; Ghazavi, K; Gidskehaug, Arne; Johannessen, J.A.; Lysaker, Dagny Iren; Nahavandchi, Hossein; Omang, Ove Christian Dahl; Pettersen, Bjørn Ragnvald; Plag, Hans-Peter; Siegismund, F.. (2005) Ocean Circulation and Transport between the North Atlantic and Arctic Sea --- status report 2005. EGU Generaly Assembly ; Vienna, Austria. 2005-04-04 - 2005-04-08.
2004
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PosterNahavandchi, Hossein; Haakonsen, Trond Arve. (2004) Correlation and spectral analysis of the Norwegian permanent GPS stations using a least-squares procedure. General Assembly- European Geosciences Union . European Geosciences Union; Nice. 2004-04-25 - 2004-04-30.
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PosterNahavandchi, Hossein; Haakonsen, Trond Arve; Plag, Hans-Peter. (2004) Principle component analysis of the Norwegian permanent GPS stations. General Assembly- European Geosciences Union (EGU) . European Geosciences Union (EGU); Nice. 2004-04-25 - 2004-04-30.
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PosterNahavandchi, Hossein; Soltanpour, Ali. (2004) Adjustment of the Surface of the Gravimetric Geoidal Height Model between Constrained GPS-levelling Stations. IAG International Symposium- Gravity, Geoid and Space Missions - GGSM2004 . International Association of Geodesy; porto. 2004-08-30 - 2004-09-03.
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Academic lectureNahavandchi, Hossein; Soltanpour, Ali. (2004) An Attempt to Define a New Height-Datum in Norway. Geodesi- og hydrografidagene 2004 . GeoForum-StatensKartverk; Sandnes. 2004-11-04 - 2004-11-05.
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PosterNahavandchi, Hossein; Soltanpour, Ali. (2004) Impact of the New GRACE Global Geopotential Model to the Geoidal Height Modeling over Norway. IAG International Symposium-Gravity, Geoid and Space Missions - GGSM2004 . International Association of Geodesy; Porto. 2004-08-30 - 2004-09-03.
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PosterNahavandchi, Hossein; Soltanpour, Ali; Nyrnes, Erik. (2004) New Gravimetric Geoidal Height Model over Norway Computed by the Least-Squares Modification Parameters. IAG International Symposium-Gravity, Geoid and Space Missions - GGSM2004 . International Association of Geodesy; Porto. 2004-08-30 - 2004-09-03.
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PosterPlag, Hans-Peter; Plag, Hans-Peter; Drange, Helge; Drange, Helge; Gidskehaug, Arne; Gidskehaug, Arne; Johannessen, J.A.; Johannessen, J.A.; Nahavandchi, Hossein; Nahavandchi, Hossein; Omang, Ove Christian Dahl; Omang, Ove Christian Dahl; Pettersen, Bjørn Ragnvald; Solheim, Dag; Solheim, Dag. (2004) OCTAS: Ocean Circulation and Heat Transport Between the North Atlantic and Arctic Sea. Forskerkonferanse for KlimaProg, KlimaEffekter og Polar klimaforskning . [Mangler data]; Lillehammer. 2004-01-07 - 2004-01-08.
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PosterSolheim, Dag; Drange, Helge; Johannessen, J.A.; Nahavandchi, Hossein; Omang, Ove Christian Dahl; Plag, Hans-Peter. (2004) Validation and Analysis of the Models for the Mean Dynamic Topography, the Mean Sea Surface Height and the Geoid in the Northern North Atlantic. Forskerkonferanse for KlimaProg, KlimaEffekter og Polar klimaforskning . [Mangler data]; Lillehammer. 2004-01-08.
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PosterSolheim, Dag; Drange, Helge; Johannessen, Johnny; Nahavandchi, Hossein; Omang, Ove Christian Dahl. (2004) Existing and new Mean Dynamic Topography, Mean Sea Surface and geiod models in the Northern North Atlantic. General Assembly-European Geosciences Union (EGU) . European Geosciences Union (EGU); Nice. 2004-04-25 - 2004-04-30.
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PosterPlag, Hans-Peter; Drange, Helge; Gidskehaug, Arne; Johannessen, J.A.; Nahavandchi, Hossein; Omang, Ove Christian Dahl; Pettersen, Bjørn Ragnvald; Solheim, Dag. (2004) OCTAS: Ocean Circulation and Heat Transport Between the North Atlantic and Arctic Sea. Forskerkonferanse for KlimaProg, KlimaEffekter og Polar klimaforskning ; Lillehammer. 2004-01-07 - 2004-01-08.
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PosterSolheim, Dag; Drange, Helge; Johannessen, J.A.; Nahavandchi, Hossein; Omang, Ove Christian Dahl; Plag, Hans-Peter. (2004) Existing and new synthetic Mean Dynamic Topography, Mean Sea Surface and geoid models in the Northern North Atlantic. 1st EGU General Assembly 2004 ; Nice, France. 2004-04-25 - 2004-04-30.
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PosterSolheim, Dag; Drange, Helge; Johannessen, J.A.; Nahavandchi, Hossein; Omang, Ove Christian Dahl; Plag, Hans-Peter. (2004) Validation and Analysis of the Models for the Mean Dynamic Topography, the Mean Sea Surface Height and the Geoid in the Northern North Atlantic. Forskerkonferanse for KlimaProg, KlimaEffekter og Polar klimaforskning ; Lillehammer. 2004-01-07 - 2004-01-08.
2003
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Academic lectureNahavandchi, Hossein. (2003) Evaluation of different methods for modification of Stokes�s integral. Geodesy Week 2003 . [Mangler data]; Germany, Hamburg. 2003-09-19.
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Academic lectureNahavandchi, Hossein. (2003) How to compute a precise geoid and why it is important. Geodesi- og hydrografidagene 2003 . [Mangler data]; Hønefoss, Norway. 2003-11-07.
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PosterNahavandchi, Hossein. (2003) Improved direct atmospheric correction in gravimetric geoid computations. EGS-AGU-EUG Joint Assembly Scientific . [Mangler data]; Nice, France. 2003-04-11.
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Academic lectureNahavandchi, Hossein. (2003) Temporal Charactristics of Multipath effects in GPS-Code and Carrier phase observations. Geodesi- og hydrografidagene 2003 . [Mangler data]; Hønefoss, Norway. 2003-11-07.
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PosterNahavandchi, Hossein; Plag, Hans-Peter. (2003) Determination of the error spectrum of continuous GPS observations. EGS-AGU-EUG Joint Assembly . [Mangler data]; Nice. 2003-04-11.
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Academic lecturePlag, Hans-Peter; Plag, Hans-Peter; Drange, Helge; Drange, Helge; Gidskehaug, Arne; Gidskehaug, Arne; Johannessen, J.A.; Johannessen, J.A.; Nahavandchi, Hossein; Nahavandchi, Hossein; Omang, Ove Christian Dahl; Omang, Ove Christian Dahl; Solheim, Dag; Solheim, Dag. (2003) Ocean Circulation and Heat Transport between the North Atlantic and Arctic Sea. The 23th General Assembly of the International Union of Geodesy and Geophysics . [Mangler data]; Japan, Sapporo. 2003-06-30 - 2003-07-11.
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Academic lecturePlag, Hans-Peter; Drange, Helge; Gidskehaug, Arne; Johannessen, J.A.; Nahavandchi, Hossein; Omang, Ove Christian Dahl; Solheim, Dag. (2003) Ocean Circulation and Heat Transport between the North Atlantic and Arctic Sea. The 23th General Assembly of the International Union of Geodesy and Geophysics ; Japan, Sapporo. 2003-06-30 - 2003-07-11.
2002
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Academic lectureNahavandchi, Hossein. (2002) Research Activities in Geodesy at Department of Geomatics, NTNU. Geodesi -og Hydrografidagene 2002 . [Mangler data]; Stavanger. 2002-11-15.
2000
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Academic lectureNahavandchi, Hossein. (2000) A new strategy for the direct terrain correction in Stokes-Helmert Scheme. European Geophysical Society General Assembly . [Mangler data]; NICE. 2000-04-29.
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PosterNahavandchi, Hossein. (2000) A robust least-squares estimation technique for the combined adjustment of gravimetric geoid at GPS-leveling stations. European Geophysical Society General Assembly . [Mangler data]; NICE. 2000-04-29.
1999
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Academic lectureNahavandchi, Hossein. (1999) Terrain correction computations with Sjoberg's and integral formulae. European Geophysical Society XXIII General Assembly . [Mangler data]; Nice, France. 1998-04-24.
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Academic lectureNahavandchi, Hossein. (1999) Unification of Vertical Datums with Application to Asia and the Pacific. Second workshop on Regional Geodetic Network . [Mangler data]; Ho Chi Minh City, Vietnam. 1999-07-13.
1998
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Academic lectureNahavandchi, Hossein. (1998) A comparison of classical and Sjoberg's approaches to terrain corrections in gravimetric geoid determination. European Geophysical Society XXIII Assembly . [Mangler data]; Nice, France. 1998-04-24.
1992
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Academic lectureNahavandchi, Hossein. (1992) The use of Spot satellite imagery for the revision of maps in Iran. First International Conference on Surveying and Mapping . [Mangler data]; Tehran, Iran. 1992-02-27.