Ole Roggenbuck

• M.Sc
• Research Assistant at Jade University of Applied Sciences

Estimating reflector heights at stationary GNSS sites with interferometric reflectometry (IR) is a well-established technique in ocean remote sensing. Additionally, IR offers the possibility to estimate the significant wave height (SWH) with a linear model using the damping coefficient from an inverse modelling applied to GNSS signal-to-noise ratio...

The signal-to-noise ratio (SNR) data is widely used in GNSS reflectometry to derive water or snow surface heights and surface characteristics like roughness or soil moisture. In a marine environment the attenuation of the SNR oscillation is related to the roughness of the sea surface. It was shown that the significant wave height (SWH) of the water...

The signal-to-noise ratio (SNR) data are part of the global navigation satellite systems (GNSS) observables. In a marine environment, the oscillation of the SNR data can be used to derive reflector heights. Since the attenuation of the SNR oscillation is related to the roughness of the sea surface, the significant wave height (SWH) of the water sur...

The signal-to-noise ratio (SNR) data is part of the global navigation satellite systems (GNSS) observables. In a marine environment, the oscillation of the SNR data can be used to derive reflector heights. Since the attenuation of the SNR oscillation is related to the roughness of the sea surface, the significant wave height (SWH) of the water surf...

Currently, GNSS reflectometry based on the signal-to-noise ratio (SNR) has become an established tool in ocean remote sensing. Here, the distance between an antenna and the water surface is measured by analyzing the oscillation of the SNR observation. Due to the antenna gain pattern, this oscillation is more pronounced for satellite signals coming...

Measurements of the sea surface height (SSH) can be carried out with GNSS aboard ships, but data about the static draft and the hydrodynamic squat effect are necessary. This information is often not available or has an insufficient accuracy. In this study, an alternative method based on the GNSS signal-to-noise ratio observations is presented. Usin...

Ships create a wave system while moving. Changing pressure conditions lead to changes in draught an trim, the so called squat effect. Knowiing about this effect is crucial from the shipping industry and if sea surface height measurments shall be done from GNSS aboard ships. The paper describes a methodology for estimating the squat via GNSS reflec...

The GNSS signal-to-noise ratio (SNR) is nowadays used in many application for the estimation of the distance between the antenna and the reflecting surface. Commonly, geodetic antennas are used for the estimation of reflector heights and surface properties. For investigations using a larger number of sensors in a particular area of investigation, i...

This poster gives a short introduction on the hydrodynamic Squat effect which describes the Change in sinkage and trim of a moving ship. One experiment were the Squat was measured directly via GNSS is explained and the resulting Squat curves are shown.

Precise measurements of the Earth’s shape, gravity field, and rotation provide critical data for many geoscientific disciplines. In order to obtain reliable data, an accurate, stable, and global reference frame is required. The International Terrestrial Reference Frame, where station positions are modeled linearly, is commonly used throughout the g...

Precise measurements of the Earth’s shape, gravity field, and rotation provide critical data for many geoscientific disciplines. In order to obtain reliable data, an accurate, stable, and global reference frame is required. The International Terrestrial Reference Frame, where station positions are modeled linearly, is commonly used throughout the g...

Every few years the International Terrestrial Reference System (ITRS) Center of the International Earth Rotation and Reference Systems Service (IERS) decides to generate a new version of the International Terrestrial Reference Frame (ITRF). For the upcoming ITRF2014 the official contribution of the International VLBI Service for Geodesy and Astrome...

Starting with the ITRF2005, the IVS contribution to the ITRF is an intra-technique combined solution using multiple individual contributions from different institutions. For the IVS contribution to the ITRF2014 nine international institutions were used for a combined solution. The data files contain 24-h VLBI sessions from the late 1970s until the...

In standard combination approaches (e.g., for the International Terrestrial Reference Frame), the space-geodetic techniques are connected by the Earth rotation parameters and by the station coordinates at co-located sites, using the so-called local ties. These local ties are usually derived from terrestrial measurements together with GNSS measureme...

With this poster the new project was introduced to the scientific community. The method of GNSS derived SSH measurements from ships is explained and previous experiments are mentioned. Finally the project ideas are explained.

The complex Earth's system undergoes everlasting changes covering a wide band of different periods and scales. Drawing conclusions about such processes, reliable measurements and a consistent, global and precise reference frame are necessary. Space-geodetic techniques used for this purpose are affected by different geophysical phenomena. Unmodeled...

Precise measurements of the shape, the gravity field and the rotation of the Earth are important for many fields of geosciences. Beside high quality sensors an accurate, stable and global reference frame is required to get reliable results. In the scientific community the International Terrestrial Reference Frame (ITRF) is commonly used, where poin...

Mit modernen Erdbeobachtungsverfahren ist es möglich das System Erde mit einer hohen zeitlichen- und räumlichen Auflösung zu vermessen und zu untersuchen. Referenzsysteme wie das ITRS und deren Realisierungen (ITRF) bilden dabei die Grundlage für hochpräzise geodätische Produkte. GGOS hat sich zum Ziel gesetzt einen globalen, hochgenauen und langze...

High quality Earth observations require an accurate, stable and global reference frame. One GGOS goal is to provide the observational basis for such a frame with 1 mm accuracy. In order to reach this ambitious goal the technique specific functional models must be improved. Beside the well known tidal effects associated with the geophysical fluids t...

Thanks to the latest developments in GNSS data processing the antenna heights aboard a ship can be determined with accuracies of up to 5 cm, also in the open ocean. These heights are a good basis to derive precise in-situ data of sea surface heights independently from satellite altimetry. However, for a reliable determination of sea surface heights...

The call for participation for the ITRF2013 asked for the first time for pre-combined contributions, although it is thought that they won’t be included in the ITRF2013 solution. But studies will be carried out how to combine single-technique and pre-combined contributions best in order to have adequate procedures ready for the next ITRF. Among the...

For a wide range of sciences it is important to know the shape of the earth, the earth gravity field, the earth rotation and their evolution in time. Especially in case of slow moving phenomena like the sea level rise it is important to have access to high quality reference frames. Reference frames like the ITRF describe the position of points with...

Die Meereshöhe (Sea Surface Height) und ihre Veränderung ist ein wesentlicher Parameter für die Analyse des Weltklimas. Aktuell wird diese auf dem offenen Ozean nahezu ausschließlich aus Fernerkundungsmethoden wie Satelliten-Altimeterie oder GNSS-Reflectometrie abgeleitet. Zur Kontrolle und Sicherung der Vertrauenswürdigkeit der Daten aber auch als...

Die Ozeane sind für das Klima auf der Erde von entscheidender Bedeutung. Der Meeresspiegel dient zudem als Indikator für die globale Erwärmung. Auf dem offenen Ozean kann die Höhe mit Satelliten Altimetern gemessen werden. An den Küsten werden Pegelstationen eingesetzt. An der Jade Hochschule Oldenburg wurden in einer Bachelorarbeit die Grundlagen...