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Lisa-S 2.8g autopilot for GPS-based flight of MAVs

Remes, B.D.W. (author), Esden-Tempski, P. (author), Van Tienen, F. (author), Smeur, E. (author), De Wagter, C. (author), De Croon, G.C.H.E. (author)

Recent advances in sensor miniaturization have enabled the development of a miniaturized fully functional autopilot. In this article, the open hardware and open software Paparazzi-UAV Lisa-S micro autopilot is presented, weighing only 2.8 grams and measuring 2 by 2 centimeters. It incorporates 2-way telemetry with a ground station, a Spektrum...

conference paper 2014

document

GPS-based precise orbit determination and accelerometry for low flying satellites

Van den IJssel, J.A.A. (author)

Atmospheric density models are currently the limiting factor in the accuracy of the dynamic orbit determination and prediction of satellites in a low Earth orbit. Any improvement in these models would greatly aid in applications such as re-entry prediction, ground-track maintenance of Earth observation satellites and forecast of possible...

doctoral thesis 2014

document

Megathrust Earthquakes: Study of Fault Slip and Stress Relaxation Using Satellite Gravity Observations

Broerse, D.B.T. (author)

During earthquakes large scale mass displacements take place when slip on a fault deforms the earth’s crust. Besides, in the days to decades after the main shock ongoing deformation is usually observed that is related to relaxation of stresses caused by the earthquake. In this thesis I relate gravity changes as observed by the GRACE satellite...

doctoral thesis 2014

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A Reconfigurable GPS/Galileo Receiver Front-end for Space Applications

Noroozi, A. (author)

The trend of space technology developments is moving from high power consuming, bulky and costly systems towards low-power, small, low-cost and flexible systems. Thus, the spacecraft can benefit from multi-purpose and flexible systems which can be low-power and low-cost by employing new technology. One example of such system is a GNSS receiver...

doctoral thesis 2013

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GNSS Carrier Phase-based Attitude Determination: Estimation and Applications

Giorgi, G. (author)

Attitude determination through the use of Global Navigation Satellite System (GNSS) signals is one of the many applications of satellite-based navigation. Multiple GNSS antennas installed on a given platform are used to provide orientation estimates, thus adding attitude information to the standard positioning service. Precise attitude estimates...

doctoral thesis 2011

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GPS-derived orbits for the GOCE satellite

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

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GOCE SSTI L2 tracking losses and their impact on POD performance

Van den IJssel, J.A.A. (author), Visser, P.N.A.M. (author), Doornbos, E.N. (author), Meyer, U. (author), Bock, H. (author), Jäggi, A. (author)

The state-of-the-art GOCE Satellite-to-Satellite Tracking Instrument (SSTI) delivers high-quality GPS data with an almost continuous 1 Hz data rate, which allows for very Precise Orbit Determination (POD). Despite this good performance, the GPS receiver shows occasional unexpected L2 tracking losses, which mainly occur close to the geomagnetic...

conference paper 2011

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Short and zero baseline analysis of GPS L1 C/A, L5Q, GIOVE E1B, and E5aQ signals

De Bakker, P.F. (author), Tiberius, C.C.J.M. (author), Van der Marel, H. (author), Van Bree, R.J.P. (author)

Stochastic properties of GNSS range measurements can accurately be estimated using a geometry-free short and zero baseline analysis method. This method is now applied to dual-frequency measurements from a new field campaign. Results are presented for the new GPS L5Q and GIOVE E5aQ wideband signals, in addition to the GPS L1 C/A and GIOVE E1B...

journal article 2011

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The integration of spaceborne accelerometry in the precise orbit determination of low-flying satellites

Van Helleputte, T. (author)

This dissertation describes the integration of accelerometer measurements of LEO-satellites in GPS-based orbit determination.

doctoral thesis 2011

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J2: An evaluation of new estimates from GPS, GRACE, and load models compared to SLR

Lavallée, D.A. (author), Moore, P. (author), Clarke, P.J. (author), Petrie, E.J. (author), Van Dam, T. (author), King, M.A. (author)

Changes in J2, resulting from past and present changes in Earth's climate, are traditionally observed by Satellite Laser ranging (SLR). Assuming an elastic Earth, it is possible to infer changes in J2 from changes in Earth's shape observed by GPS. We compare estimates of non-secular J2 changes from GPS, SLR, GRACE, and a load model. The GPS and...

journal article 2010

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Preliminary Analysis of a Novel SAR Based Emergency System for Earth Orbit Satellites using Galileo

Gill, E.K.A. (author), Helderweirt, A. (author)

This paper presents a preliminary analysis of a novel Search and Rescue (SAR) based emergency system for Low Earth Orbit (LEO) satellites using the Galileo Global Navigation Satellite System (GNSS). It starts with a description of the space user SAR system including a concept description, mission architecture and legal and regulatory aspects....

conference paper 2010

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Snapshot Software Receiver for GNSS in Weak Signal Environments: An Innovative Approach for Galileo E5

Carrasco-Martos, S. (author), López-Risueño, G. (author), Jiménez-Baños, D. (author), Gill, E.K.A. (author)

Global Navigation Satellite System (GNSS) positioning has turned out to be an enabler of Location-Based Services (LBS). This has motivated in recent years an increasing research activity on signal processing techniques for GNSS receivers. However, one main limitation faced by these GNSS receivers is the propagation of GNSS signals in complex...

conference paper 2010

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Improved constraints on models of glacial isostatic adjustment: A review of the contribution of ground-based geodetic observations

King, M.A. (author), Altamimi, Z. (author), Boehm, J. (author), Bos, M. (author), Dach, R. (author), Elosegui, P. (author), Fund, F. (author), Hernández-Pajares, M. (author), Lavallee, D. (author), Riva, E.M. (author)

The provision of accurate models of Glacial Isostatic Adjustment (GIA) is presently a priority need in climate studies, largely due to the potential of the Gravity Recovery and Climate Experiment (GRACE) data to be used to determine accurate and continent-wide assessments of ice mass change and hydrology. However, modelled GIA is uncertain due...

journal article 2010

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Autonomous formation flying in low earth orbit

D'Amico, S. (author)

Formation flying is commonly identified as the collective usage of two or more cooperative spacecraft to exercise the function of a single monolithic virtual instrument. The distribution of tasks and payloads among fleets of coordinated smaller satellites offers the possibility to overcome the classical limitations of traditional single...

doctoral thesis 2010

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Geometry-free undifferenced, single and double differenced analysis of single frequency GPS, EGNOS and GIOVE-A/B measurements

De Bakker, P.F. (author), Van der Marel, H. (author), Tiberius, C.C.J.M. (author)

This paper demonstrates a geometry-free GNSS measurement analysis approach and presents results of single frequency GPS, EGNOS and GIOVE short and zero baseline measurements. The purpose is to separate the different contributions to the measurement noise of pseudo range code and carrier phase observations at the receiver. The influence of...

journal article 2009

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ADOP in closed form for a hierarchy of multi-frequency single-baseline GNSS models

Odijk, D. (author), Teunissen, P.J.G. (author)

Successful carrier phase ambiguity resolution is the key to high-precision positioning with Global Navigation Satellite Systems (GNSS). The ambiguity dilution of precision (ADOP) is a well-known scalar measure which can be used to infer the strength of the GNSS model for carrier phase ambiguity resolution. In this contribution we present...

journal article 2008

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Signal and noise in Gravity Recovery and Climate Experiment (GRACE) observed surface mass variations

Schrama, E.J.O. (author), Wouters, B. (author), Lavallée, D.A. (author)

The Gravity Recovery and Climate Experiment (GRACE) product used for this study consists of 43 monthly potential coefficient sets released by the GRACE science team which are used to generate surface mass thickness grids expressed as equivalent water heights (EQWHs). We optimized both the smoothing radius and the level of approximation by...

journal article 2007

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Fast error analysis of continuous GPS observations

Bos, M.S. (author), Fernandes, R.M.S. (author), Williams, S.D.P. (author), Bastos, L. (author)

It has been generally accepted that the noise in continuous GPS observations can be well described by a power-law plus white noise model. Using maximum likelihood estimation (MLE) the numerical values of the noise model can be estimated. Current methods require calculating the data covariance matrix and inverting it, which is a significant...

journal article 2007

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Accuracy assessment of the monthly GRACE geoids based upon a simulation

Schrama, E.J.O. (author), Visser, P.N.A.M. (author)

journal article 2007

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Microblock rotations and fault coupling in SE Asia triple junction (Sulawesi, Indonesia) from GPS and earthquake slip vector data

Socquet, A. (author), Simons, W.J.F. (author), Vigny, C. (author), McCaffrey, R. (author), Subarya, C. (author), Sarsito, D. (author), Ambrosius, B. (author), Spakman, W. (author)

The island of Sulawesi, eastern Indonesia, is located within the triple junction of the Australian, Philippine, and Sunda plates and accommodates the convergence of continental fragments with the Sunda margin. We quantify the kinematics of Sulawesi by modeling GPS velocities and earthquake slip vectors as a combination of rigid block rotations...

journal article 2006