On the interaction between tides and stratification in the Rhine Region of Freshwater Influence

Design of a deployment rotation mechanism for microsatellite

Solar array rotation mechanism provides a hinged joint between the solar panel and satellite body, smooth rotation of the solar array into deployed position and its fixation in this position. After unlocking of solar panel (while in orbit), rotation bracket turns towards ready-to-work position under the action of driving spring. During...

Monitoring surface deformation induced by hydrocarbon production using satellite radar interferometry

The start of hydrocarbon production in the 1960s in the northeastern part of the Netherlands has resulted in subsidence of the ground level, which has been estimated from periodic leveling campaigns. Although leveling is a precise and reliable technique for subsidence monitoring, it is labor intensive, expensive and poses a safety risk since...

Assembly, integration and testing of the Delfi-C³ nanosatellite

At the Delft University of Technology, the Delfi-C3 3-unit Cube Sat was finalised for launch on PSLV C9. An overview is presented about manufacturing, assembly, integration and verification activities on subsystems and Proto Flight Model (PFM) until delivery for launch. Delfi-C3 is the first Dutch university satellite and the fourth Dutch...

Shallow-earth rheology from glacial isostasy and satellite gravity: A sensitivity analysis for GOCE

In recent years, satellite gravity missions have been launched that probe the earth's long- to mediumwavelength (1000 - 500 km) gravity field. The upcoming ESA satellite gravity mission GOCE is predicted to measure the gravity field with an accuracy of a few centimeters at spatial scales of 100 km. Such a high-resolution gravity field contains...

Hydrotope-Based Protocol to Determine Average Soil Moisture Over Large Areas for Satellite Calibration and Validation With Results From an Observation Campaign in the Volta Basin, West Africa

In West Africa, which is an extremely moisturelimited region, soil water information plays a vital role in hydrologic and meteorologic modeling for improved water resource planning and food security. Recent and upcoming satellite missions, such as SMOS and MetOp, hold promise for the regional observation of soil moisture. The resolution of the...

Global soil moisture patterns observed by space borne microwave radiometers and scatterometers

Within the scope of the upcoming launch of a new water related satellite mission (SMOS) a global evaluation study was performed on two available global soil moisture products. ERS scatterometer surface wetness data was compared to AMSR-E soil moisture data. This study pointed out a strong similarity between both products in sparse to moderate...

Frequency-dependent data weighting in global gravity field modeling from satellite data contaminated by non-stationary noise

A boy's dream the size of a milk carton

Student satellites are the latest hype in education. By allowing students to build their own satellites, they learn to solve problems faster and build more innovatively. In Delft, students are now putting the final touches on the Delft-C3, a nanosatellite the size of a milk carton. For every student, and for the instructors as well, this a boys...

‘DEOS CHAMP-01C 70’: A model of the Earth’s gravity field computed from accelerations of the CHAMP satellite

Performance of a recently proposed technique for gravity field modeling has been assessed with data from the CHAMP satellite. The modeling technique is a variant of the acceleration approach. It makes use of the satellite accelerations that are derived from the kinematic orbit with the 3-point numerical differentiation scheme. A 322-day data set...

The GNSS integer ambiguities: Estimation and validation

The principle of positioning with the Global Positioning System (GPS) is based on determining the distance of at least four GPS satellites to a receiver. For that purpose the so-called code measurements can be used, so that the position of the receiver can be determined up to several meters. In order to allow for navigation with centimeter...

How to handle colored observation noise in large least-squares problems

An approach to handling colored observation noise in large least-squares (LS) problems is presented. The handling of colored noise is reduced to the problem of solving a Toeplitz system of linear equations. The colored noise is represented as an auto regressive moving-average (ARMA) process. Stability and invertability of the ARMA model allows...

A Monte-Carlo technique for weight estimation in satellite geodesy

Precise orbit determination, and satellite-geodetic applications such as gravity field modelling or satellite altimetry, rely on different observation types and groups that have to be processed in a common parameter estimation scheme. Naturally, the choice of the relative weights for these data sets as well as for added prior information is of...

A decade of ERS satellite orbits and altimetry

The First European Remote Sensing Satellite, ERS-1, was launched in July 1991, fol- lowed by ERS-2 in April 1995. Both satellites carry a radar altimeter to serve oper- ational applications and scientific research in the fields of geodesy, oceanography, glaciology and meteorology. Together, the satellites have now been operating for over twelve...

Eurofix: Test Results of a Cost-Effective DGNSS Augmentation System

Eurofix is an integrated navigation system, which combines Differential GNSS and Loran-C. The Loran-C system is used to provide differential corrections for the GNSS pseudo-range measurements and integrity information by additionally modulating the transmitted signals. This modulation, however, is not allowed to degrade normal Loran-C operations...

Positioning of the Tromso station by satellite laser ranging; Campaign 1990 data acquisition and analysis