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

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...

Theory of carrier adjusted DGPS positioning approach and some experimental results

Autonomous formation flying in low earth orbit

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...

Present-day kinematics at the Azores-Gibraltar plate boundary as derivated from GPS observations

Multipath and multi-transmitter interference in spread-spectrum communication and navigation systems

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

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

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

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...

GNSS Carrier Phase-based Attitude Determination: Estimation and Applications

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...

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

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...

On User Algorithms for GNSS Precise Point Positioning

Precise Point Positioning (PPP) is a Global Navigation Satellite System (GNSS) processing method with the objective of providing high positioning accuracy without the need for a nearby base station or dense network of reference stations operated by the user. To reach this objective, PPP uses the very precise carrier phase measurements in...

Absolute and Relative Orbit Determination for Satellite Constellations

Precise absolute and relative orbit determination, referred to as Precise Orbit Determination (POD) and Precise Baseline Determination (PBD), are a prerequisite for the success of many Low Earth Orbit (LEO) satellite missions. With the spaceborne, high-quality, multi-channel, dual-frequency Global Positioning System (GPS) receivers, typically a...