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Introducing the Azimuth Cutoff as an Independent Measure for Characterizing Sea-State Dynamics in SAR Altimetry

Altiparmaki, O. (author), Amraoui, Samira (author), Kleinherenbrink, M. (author), Moreau, Thomas (author), Maraldi, Claire (author), Visser, P.N.A.M. (author), Naeije, M.C. (author)

This study presents the first azimuth cutoff analysis in Synthetic Aperture Radar (SAR) altimetry, aiming to assess its applicability in characterizing sea-state dynamics. In SAR imaging, the azimuth cutoff serves as a proxy for the shortest waves, in terms of wavelength, that can be detected by the satellite under certain wind and wave...

journal article 2024

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Relative Sea Level Trends for the Coastal Areas of Peninsular and East Malaysia Based on Remote and In Situ Observations

Simons, W.J.F. (author), Naeije, M.C. (author), Ghazali, Zaki (author), Darani Rahman, Wan (author), Cob, Sanusi (author), Kadir, Majid (author), Bin Mustafar, M.A. (author), Din, Ami Hassan (author), Efendi, Joni Efendi (author), Noppradit, Prakrit (author)

Absolute sea-level rise has become an important topic globally due to climate change. In addition, relative sea-level rise due to the vertical land motion in coastal areas can have a big societal impact. Vertical land motion (VLM) in Southeast Asia includes a tectonically induced component: uplift and subsidence in plate boundary zones where...

journal article 2023

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CryoSat Long-Term Ocean Data Analysis and Validation: Final Words on GOP Baseline-C

Naeije, M.C. (author), Di Bella, Alessandro (author), Geminale, Teresa (author), Visser, P.N.A.M. (author)

ESA’s Earth explorer mission CryoSat-2 has an ice-monitoring objective, but it has proven to also be a valuable source of observations for measuring impacts of climate change over oceans. In this paper, we report on our long-term ocean data analysis and validation and give our final words on CryoSat-2’s Geophysical Ocean Products (GOP)...

journal article 2023

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Update on CryoSat-2 long-term ocean data analysis and validation

Naeije, M.C. (author), Schrama, Ernst (author), Di Bella, Alessandro (author), Bouffard, Jerome (author)

ESA’s Earth Explorer CryoSat-2 precisely measures the changes in the thickness of marine ice floating on the polar oceans and variations in the thickness of the vast ice sheets that overlie Greenland and Antarctica. The data delivered by the CryoSat-2 mission completes the picture to determine and understand the ice role in the Earth system in...

poster 2022

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Lead Detection in the Arctic Ocean from Sentinel-3 Satellite Data: A Comprehensive Assessment of Thresholding and Machine Learning Classification Methods

Bij de Vaate, I. (author), Martin, Ericka (author), Slobbe, D.C. (author), Naeije, M.C. (author), Verlaan, M. (author)

In the Arctic Ocean, obtaining water levels from satellite altimetry is hampered by the presence of sea ice. Hence, water level retrieval requires accurate detection of fractures in the sea ice (leads). This paper describes a thorough assessment of various surface type classification methods, including a thresholding method, nine supervised-,...

journal article 2022

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Epoch-Based Height Reference System for Sea Level Rise Impact Assessment on the Coast of Peninsular Malaysia

Cob, Sanusi (author), Kadir, Majid (author), Forsberg, Rene (author), Simons, W.J.F. (author), Naeije, M.C. (author), Din, Ami Hassan (author), Yacob, Husaini (author), Amat, Asyran (author), Mahdzur, Daud (author)

The Peninsular Malaysia Geodetic Vertical Datum 2000 (PMGVD2000) inherited several deficiencies due to offsets between local datums used, levelling error propagations, land subsidence, sea level rise, and sea level slopes along the southern half of the Malacca Strait on the west coast and the South China Sea in the east coast of the...

journal article 2022

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SAR altimetry data as a new source for swell monitoring

Altiparmaki, O. (author), Kleinherenbrink, M. (author), Naeije, M.C. (author), Slobbe, D.C. (author), Visser, P.N.A.M. (author)

This article shows the first spectral analysis of fully-focused Synthetic Aperture Radar (FFSAR) altimetry data with the objective of studying backscatter modulations caused by swells. Swell waves distort the backscatter in altimetry radargrams by means of velocity and range bunching. These swell signatures are visible in the tail of the...

journal article 2022

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Monitoring Megathrust-Earthquake-Cycle-Induced Relative Sea-Level Changes near Phuket, South Thailand, Using (Space) Geodetic Techniques

Naeije, M.C. (author), Simons, W.J.F. (author), Pradit, Siriporn (author), Niemnil, Sommart (author), Thongtham, Nalinee (author), Bin Mustafar, M.A. (author), Noppradit, Prakrit (author)

Temporal changes in vertical land motion (VLM) in and around Phuket Island in southern Thailand following the great 2004 Sumatra–Andaman megathrust earthquake have impacted the relative sea-level change estimates based on tide-gauge (TG) records. To better monitor the VLM, two new continuous global navigation satellite system (GNSS) stations...

journal article 2022

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A Tsunami Generated by a Strike-Slip Event: Constraints From GPS and SAR Data on the 2018 Palu Earthquake

Simons, W.J.F. (author), Broerse, D.B.T. (author), Kleptsova, O.S. (author), Nijholt, N. (author), Pietrzak, J.D. (author), Naeije, M.C. (author), Lhermitte, S.L.M. (author), Visser, P.N.A.M. (author), Riva, R.E.M. (author)

A devastating tsunami struck Palu Bay in the wake of the 28 September 2018 M_w = 7.5 Palu earthquake (Sulawesi, Indonesia). With a predominantly strike-slip mechanism, the question remains whether this unexpected tsunami was generated by the earthquake itself, or rather by earthquake-induced landslides. In this study we examine the...

journal article 2022

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Orbit design of a swarm for ultra-long wavelength radio interferometry with preliminary swarm and thruster sizing

Nevinskaia, A.S. (author), Bentum, Mark J. (author), Engelen, S. (author), Monna, Bert (author), Naeije, M.C. (author)

Observing the universe in the Ultra-Long Wavelength (ULW) regime has been called the ‘last frontier in astronomy’—real imaging capabilities here are yet to be achieved. Obtaining an image of the sky in this frequency band can be done by employing a swarm of satellites that together act as an interferometer and collect the required imaging...

journal article 2021

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From the martian surface to its low orbit in a reusable single-stage vehicle—charon

Gaffarel, Jérémie (author), Kadhum, Afrasiab (author), Fazaeli, Mohammad (author), Apostolidis, Dimitrios (author), Berger, Menno (author), Ciunaitis, Lukas (author), Helsdingen, Wieger (author), Landergren, Lasse (author), Lentner, Mateusz (author), Neeser, Jonathan (author), Trotta, Luca (author), Naeije, M.C. (author)

With Mars colonisation becoming a reality for the near future, it is of importance to analyse how crew and cargo can be transported between Earth and a colony on Mars. This article is a feasibility and design study of a launch vehicle whose mission is to shuttle crew and cargo from Low Mars Orbit to a colony on the Martian surface. A single...

journal article 2021

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Altimetry for the future: Building on 25 years of progress

Abdalla, S. (author), Kolachina, A. (author), Adusumilli, S. (author), Bhowmick, A (author), Alou-Font, E. (author), Amarouche, L. (author), Andersen, OB (author), Naeije, M.C. (author), Simons, W.J.F. (author)

In 2018 we celebrated 25 years of development of radar altimetry, and the progress achieved by this methodology in the fields of global and coastal oceanography, hydrology, geodesy and cryospheric sciences. Many symbolic major events have celebrated these developments, e.g., in Venice, Italy, the 15th (2006) and 20th (2012) years of progress and...

journal article 2021

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A recovery system for the key components of the first stage of a heavy launch vehicle

Dek, Casper (author), Overkamp, Jean Luc (author), Toeter, Akke (author), Hoppenbrouwer, Tom (author), Slimmens, Jasper (author), van Zijl, Job (author), Areso Rossi, Pietro (author), Machado, Ricardo (author), Hereijgers, Sjef (author), Kilic, Veli (author), Naeije, M.C. (author)

In recent years, the space market has been pushing towards decreasing costs of launching spacecraft by reusing parts of the launchers. The purpose of this article is to present a feasibility study of a recovery system for the engine and engine frame of an existing, expendable heavy launch vehicle and present recommendations for further...

journal article 2020

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The second-order effect of Earth’s rotation on Cryosat-2 fully focused SAR processing

Kleinherenbrink, M. (author), Smith, Walter H.F. (author), Naeije, M.C. (author), Slobbe, D.C. (author), Hoogeboom, P. (author)

We investigated the sensitivity of fully focused SAR (FF-SAR) processing of Cryosat-2 altimeter data to Earth rotation. Earth’s rotation causes scatterers at varying cross-track locations to have a different relative velocity with respect to the satellite. This second-order effect of Earth rotation on the phase is currently not corrected for...

journal article 2020

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The performance of CryoSat-2 fully-focussed SAR for inland water-level estimation

Kleinherenbrink, M. (author), Naeije, M.C. (author), Slobbe, D.C. (author), Egido, Alejandro (author), Smith, Walter (author)

This paper applies the Fully-Focussed SAR (FF-SAR) algorithm to CryoSat-2 full-bit-rate data to measure water levels of lakes and canals in the Netherlands, and validates these measurements by comparing them to heights measured by gauges. Over Lake IJssel, a medium-sized lake, the FF-SAR height is biased about 6 cm below the gauge height, and...

journal article 2020

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Long-term impacts of rising sea temperature and sea level on shallow water coral communities over a similar to 40 year period

Brown, B. E. (author), Dunne, R. P. (author), Somerfield, P. J. (author), Edwards, A. J. (author), Simons, W.J.F. (author), Phongsuwan, N. (author), Putchim, L. (author), Anderson, L. (author), Naeije, M.C. (author)

Effects of combined rising sea temperature and increasing sea level on coral reefs, both factors associated with global warming, have rarely been addressed. In this ~40 y study of shallow reefs in the eastern Indian Ocean, we show that a rising relative sea level, currently estimated at ~11 mm y−1, has not only promoted coral cover but also has...

journal article 2019

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Improved Retrieval Methods for Sentinel-3 SAR Altimetry over Coastal and Open Ocean and recommendations for implementation: ESA SCOOP Project Results

Cotton, David (author), Varona, Eduard (author), Gommenginger, Christine (author), Dayoub, Nadim (author), Cancet, Mathilde (author), Fenoglio-Marc, Luciana (author), Naeije, M.C. (author), Guerreiro, Joana Fernandes (author), Shaw, Andrew GP (author)

The European Sentinel-3A satellite, launched by ESA in February 2016, followed by Sentinel-3B in April 2018, as a part of the Copernicus programme, is the second satellite to operate a SAR mode altimeter. SRAL is operated in SAR mode over the whole ocean and promises increased performance w.r.t. conventional altimetry. SCOOP (SAR Altimetry...

poster 2019

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Design and Analysis of an Airborne, solid Propelled, Nanosatellite Launch Vehicle using Multidisciplinary Design Optimization

Van Kesteren, M.W. (author), Zandbergen, B.T.C. (author), Naeije, M.C. (author), Van Kleef, A.J.P. (author)

The work focusses on the use of multidisciplinary optimization to design a cost optimized airborne nanosatellite launch vehicle capable of bringing a 10 kg payload into low earth orbit (LEO). Piggyback or shared launch options currently available for nanosatellites are relatively low cost (~45,000 €/kg) but have as serious disadvantage a limited...

conference paper 2015

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Improved Oceanographic Measurements from SAR Altimetry: Results and Scientific Roadmap from the ESA CryoSat Plus For Oceans Project

Cotton, D. (author), Andersen, O. (author), Boy, F. (author), Cancet, M. (author), Dinardo, S. (author), Gommenginger, C. (author), Egido, A. (author), Fernandes, J. (author), Nilo Garcia, P. (author), Lucas, B. (author), Moreau, T. (author), Naeije, M.C. (author), Scharroo, R. (author), Stenseng, L. (author), Benveniste, J. (author)

journal article 2015

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Unified State Model theory and application in astrodynamics

Vittaldev, V. (author), Mooij, E. (author), Naeije, M.C. (author)

The Unified State Model is a method for expressing orbits using a set of seven elements. The elements consist of a quaternion and three parameters based on the velocity hodograph. A complete derivation of the original model is given in addition to two proposed modifications. Both modifications reduce the number of state elements from seven to...

journal article 2012