- document
-
Feng, J. (author), Noomen, R. (author), Visser, P.N.A.M. (author), Yuan, J. (author)The existence and characteristics of periodic orbits (POs) in the vicinity of a contact binary asteroid are investigated with an averaged spherical harmonics model. A contact binary asteroid consists of two components connected to each other, resulting in a highly bifurcated shape. Here, it is represented by a combination of an ellipsoid and a...journal article 2015
- document
-
Visser, P.N.A.M. (author)A method has been developed and tested for estimating calibration parameters for the six accelerometers on board the Gravity field and steady-state Ocean Circulation Explorer (GOCE) from star tracker observations. These six accelerometers are part of the gradiometer, which is the prime instrument on board GOCE. It will be shown that by taking...journal article 2008
- document
-
Visser, P.N.A.M. (author), Van den IJssel, J. (author)The computation of high-accuracy orbits is a prerequisite for the success of Low Earth Orbiter (LEO) missions such as CHAMP, GRACE and GOCE. The mission objectives of these satellites cannot be reached without computing orbits with an accuracy at the few cm level. Such a level of accuracy might be achieved with the techniques of reduced-dynamic...journal article 2003
- document
-
Bouman, J. (author), Fuchs, M. (author), Ivins, E. (author), Van der Wal, W. (author), Schrama, E.J.O. (author), Visser, P.N.A.M. (author), Horwath, M. (author)The orbit and instrumental measurement of the Gravity Field and Steady State Ocean Circulation Explorer (GOCE) satellite mission offer the highest ever resolution capabilities for mapping Earth's gravity field from space. However, past analysis predicted that GOCE would not detect changes in ice sheet mass. Here we demonstrate that GOCE gravity...journal article 2014
- document
-
Bock, H. (author), Jäggi, A. (author), Meyer, U. (author), Visser, P.N.A.M. (author), Van den IJssel, J.A.A. (author), Van Helleputte, T. (author), Heinze, M. (author), Hugentobler, U. (author)The first ESA (European Space Agency) Earth explorer core mission GOCE (Gravity field and steady-state Ocean Circulation Explorer) was launched on 17 March 2009 into a sun-synchronous dusk–dawn orbit with an exceptionally low initial altitude of about 280 km. The onboard 12-channel dual-frequency GPS (Global Positioning System) receiver delivers...journal article 2011
- document
-
Visser, P.N.A.M. (author), Van den IJssel, J.A.A. (author)The European Space Agency Gravity field and steady-state Ocean Circular Explorer (GOCE) carries a gradiometer consisting of three pairs of accelerometers in an orthogonal triad. Precise GOCE science orbit solutions (PSO), which are based on satellite-to-satellite tracking observations by the Global Positioning System and which are claimed to be...journal article 2014
- document
-
Gruber, T. (author), Visser, P.N.A.M. (author), Ackermann, C. (author), Hosse, M. (author)Three GOCE-based gravity field solutions have been computed by ESA’s high-level processing facility and were released to the user community. All models are accompanied by variance-covariance information resulting either from the least squares procedure or a Monte-Carlo approach. In order to obtain independent external quality parameters and to...journal article 2011
- document
-
Visser, P.N.A.M. (author)A method has been implemented and tested for estimating bias and scale factor parameters for all six individual accelerometers that will fly on-board of GOCE and together form the so-called gradiometer. The method is based on inclusion of the individual accelerometer observations in precise orbit determinations, opposed to the baseline method...journal article 2008
- document
-
Liu, H. (author), Lühr, H. (author), Watanabe, S. (author), Köhler, W. (author), Henize, V. (author), Visser, P.N.A.M. (author)Using 3 years (2002–2004), over 16,400 orbits of measurements from the accelerometer on board the CHAMP satellite, we have studied the climatology of the equatorial zonal wind in the upper thermosphere. Several main features are noticed. The most prominent one is that the solar flux significantly influences both the daytime and nighttime winds....journal article 2006
- document
-
Fuchs, M.J. (author), Bouman, J. (author), Broerse, D.B.T. (author), Visser, P.N.A.M. (author), Vermeersen, L.L.A. (author)The Japan Tohoku-Oki earthquake (9.0 Mw) of 11 March 2011 has left signatures in the Earth's gravity field that are detectable by data of the Gravity field Recovery and Climate Experiment (GRACE) mission. Because the European Space Agency's (ESA) satellite gravity mission Gravity field and steady-state Ocean Circulation Explorer (GOCE)—launched...journal article 2013
- document
-
Bouman, J. (author), Fiorot, S. (author), Fuchs, M. (author), Gruber, T. (author), Schrama, E.J.O. (author), Tscherning, C. (author), Veicherts, M. (author), Visser, P.N.A.M. (author)GOCE is ESA’s gravity field mission and the first satellite ever that measures gravitational gradients in space, that is, the second spatial derivatives of the Earth’s gravitational potential. The goal is to determine the Earth’s mean gravitational field with unprecedented accuracy at spatial resolutions down to 100 km. GOCE carries a gravity...journal article 2011
- document
- Schrama, E.J.O. (author), Visser, P.N.A.M. (author) journal article 2007
- document
-
Visser, P.N.A.M. (author), Sneeuw, N. (author), Gerlach, C. (author)A fast iterative method for gravity field determination from low Earth satellite orbit coordinates has been developed and implemented successfully. The method is based on energy conservation and avoids problems related to orbit dynamics and initial state. In addition, the particular geometry of a repeat orbit is exploited by using a very...journal article 2003
- document
-
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
- document
-
Fayolle-Chambe, M.S. (author), Dirkx, D. (author), Visser, P.N.A.M. (author), Lainey, V. (author)Context. The apparent close encounters of two satellites in the plane of the sky, called mutual approximations, have been suggested as a different type of astrometric observation to refine the moons' ephemerides. The main observables are then the central instants of the close encounters, which have the advantage of being free of any scaling...journal article 2021
- document
-
Liu, Y. (author), Noomen, R. (author), Visser, P.N.A.M. (author)We develop a Gravity Assist Mapping to quantify the effects of a flyby in a two-dimensional circular restricted three-body situation based on Gaussian Process Regression (GPR). This work is inspired by the Keplerian Map and Flyby Map. The flyby is allowed to occur anywhere above 300 km altitude at the Earth in the system of Sun-(Earth+Moon)...journal article 2021
- document
-
De Breuker, R. (author), Benedictus, R. (author), Bisagni, C. (author), Boneschansker, I. (author), Melkert, J.A. (author), Snellen, M. (author), Veldhuis, L.L.M. (author), Verdegaal, F.M. (author), Visser, P.N.A.M. (author), Werij, H.G.C. (author)The Faculty of Aerospace Engineering is one of eight faculties at Delft University of Technology. It is one of the most comprehensive academic and innovation communities worldwide focusing on aerospace engineering. Its 120 professors and 70 researchers are mentoring and teaching around 2,800 BSc/MSc students and more than 350 PhD candidates...journal article 2022
- document
- Visser, T. (author), Doornbos, E.N. (author), de Visser, C.C. (author), Visser, P.N.A.M. (author), Fritsche, Bent (author) journal article 2018
- document
-
Schrama, Ernst (author), Visser, P.N.A.M. (author)In this paper we review the precision orbit determination (POD) performance of the CryoSat-2 mission where we used all tracking data between June-2010 and Jan-2023; with station and beacon coordinates provided in the ITRF2020 reference system, we use a mean gravity model, and we use spacecraft specific models for modeling drag and radiation...journal article 2023
- document
-
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