G. J. Grenzdörffer

G. J. Grenzdörffer
University of Rostock · Faculty of Agricultural and Environmental Sciences

Dr.-Ing.

About

67
Publications
23,561
Reads
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685
Citations
Introduction
G. J. Grenzdörffer currently works at the Faculty of Agricultural and Environmental Sciences, University of Rostock. G. does research in UAV-Photogrammetry, Remote Sensing, Geoinformatics (GIS) and Precision Farming.
Additional affiliations
April 1994 - present
University of Rostock
Position
  • Professor (Associate)
April 1994 - present
University of Rostock
Position
  • Professor (Associate)
Description
  • Teaching experience: Precision Farming, GIS-Basics, Remote Sensing, Geo-Imaging, Geomorphology, Cartography, UAV-Photogrammetry
Education
April 1994 - December 2001
University of Rostock
Field of study
  • Geoinformatics
August 1990 - May 1991
Louisiana State University
Field of study
  • Geography
October 1987 - February 1994
University of Tuebingen
Field of study
  • Geography

Publications

Publications (67)
Article
RTK-GNSS, Drohnen, Satellitenfernerkundung, Deep Learning etc. sind nicht nur im Vermessungswesen üblich, sondern auch der Landwirtschaft gebräuchlich. Der Beitrag geht im Besonderen auf die teilflächenspezifische Anwendung von Herbiziden ein, bei der die genannten Technologien dazu führen werden, dass die Aufwandmengen an Herbiziden um ca. 50 % ge...
Book
Das Buch geht in 124 Seiten aud alle Aspekte der Nutzung von Dorhnen in der Landwirtscahft ein. Von den Grundlagen der landwirtschaftlichen Fernerkundung, über Fluggerätetechnik und Photogrammetrie bis hin zu den rechtlichen Vorgaben. Anwendungsbeispiele zeigen die breiten Einsatzmöglichkeiten.
Article
Full-text available
Grazing is a suitable option for managing the habitat functions of restored fen grasslands. Nevertheless, nutritional requirements of the grazing livestock need to be considered to make such grazing systems sustainable. In order to analyze the interactions between the development of forage nutritive values, grazing behaviour and resulting liveweigh...
Article
Full-text available
In order to get accurate information about the volume of a partly filled bin of packaging waste a dedicated smartphone app was developed. The main functions of the app are to collect sets of images, which are sent to an external server (cloud) for automatic photogrammetric image processing. The results, basically the filling volume is transferred b...
Chapter
Zu den großen kommunalen Herausforderungen des 21. Jahrhunderts gehört es, die negativen Auswirkungen der zunehmenden Urbanisierung und des sich verstärkenden Klimawandels auf den städtischen Lebensraum abzupuffern. Im Unterschied zu verschiedenen technischen Maßnahmen (z.B. Reduzierung des urban heat island-Effektes durch Dächer mit reflektierende...
Conference Paper
Full-text available
Zusammenfassung: Datengrundlage für die Ermittlung urbaner Überwärmungszonen ist eine langfristige Auswertung der Oberflächentemperaturen der Stadt. Dazu sind über einen Zeit-raum von 20 Jahren 47 Satellitenszenen (Landsat 5,7,8) der Sommermonate (Ende März – Anfang September) ausgewählt worden. Der langfristige Datensatz gewährleistet, dass die da...
Article
The rewetting of drained peatlands to re-establish rare biodiversity of peat-forming vegetation is a long-term process. In order to assess this process, a monitoring concept is required that is operational, cost-effective and non-invasive to the sensitive ecosystem. Multisensory data collected by an Unmanned Aerial System (UAS) has great potential...
Article
Full-text available
Multitemporal drone surveys are a perfect tool to determine various geometric and spectral crop parameters for rapid phenotyping in field trials. Depending on the geometric resolution and the size of the crop, information at leaf level or canopy level can be obtained. The focus of this paper is to demonstrate which geometric properties can be autom...
Article
The restoration of drained peatlands to re-establish biodiverse peat-forming plant communities and typical habitats is a long-term process. To document this process, monitoring concepts must be found that are as operational, cost-effective and non-invasive as possible for the new sensitive ecosystems. The monitoring of the developing plant communit...
Conference Paper
Full-text available
Die Ufer der Tideelbe im Wechselspiel von Mensch und Umwelt. Vegetation, Boden und Ökosystemleistungen Ergebnisse der Forschungsprojekte ElbService und tibass sowie Zwischenergebnisse des Makrophytenmonitorings der Beweissicherung Tideelbe Inhalte: 1. Einführung 2. Vegetation 2.1. Schiffswellen an den Pflanzen 2.2. Die Wellen hinter den Pflanzen 2....
Technical Report
Full-text available
Feasility study of the use of multispectral and multisesnoral drones for the quantitative measurement of selected vegetation properties of tidal vegetation
Conference Paper
Full-text available
UAS liefern sehr hochaufgelöste multisensorale Daten, mit deren Hilfe und unter Verwendung moderner Klassifikatoren eine präzise Vegetationsklassifikation eines Moores möglich wird. Der im Rahmen einer UAS-Befliegung aufgenommene multisensorale Datensatz (14 Bänder), einer ca. 8 ha großen Moorfläche, besteht aus RGB-Daten, multispektralen Informati...
Conference Paper
Full-text available
UAS bzw. Drohnen werden in wenigen Jahren schon zum Standardwerkzeug im Feldversuchswesen gehören, da viele pflanzenbauliche relevante Informationen auf der Ebene der Einzelpflanzen mehr oder weniger automatisch aus den 3D-Geodaten extrahiert werden können. Am Beispiel eines Eisbergsalatversuchs wird der generelle Workflow vorgestellt und erläutert...
Conference Paper
Full-text available
Zentimetern über einen Zeitraum von ca. zwei Jahren zu beschreiben. Die in diesem Zeitraum zu beobach-teten saisonalen Veränderungen auf den Wattflächen betragen bis zu ± 20 cm, gleichen sich aber oftmals wieder aus.
Article
Full-text available
The desire to obtain a better understanding of ecosystems and process dynamics in nature accentuates the need for observing these processes in higher temporal and spatial resolutions. Linked to this, the measurement of changes in the external structure and phytomorphology of plants is of particular interest. In the fields of environmental research...
Article
Full-text available
Great efforts are presently taken in the scientific community to develop computerized and (fully) automated image processing methods allowing for an efficient and automatic monitoring of sea birds and marine mammals in ever-growing amounts of aerial imagery. Currently the major part of the processing, however, is still conducted by especially train...
Conference Paper
Full-text available
Zusammenfassung: Der Bedarf und die Nachfrage nach UAS-Befliegungsdienstleistungen durch Behörden und Firmen, z.B. zur 3D-Datenerfassung und Kartierung von beliebigen Ob-jekten nehmen rasant zu. Gleichzeitig entstehen viele neue Firmen, die photogrammetrische Standardprodukte anbieten wollen, ohne über entsprechende photogrammetrische Grund-kenntni...
Article
Full-text available
UAS become a very valuable tool for coastal morphology. Not only for mapping but also for change detection and a better understanding of processes along and across the shore. This contribution investigates the possibilities of UAS to determine the water depth in clear shallow waters by means of the so called "photo bathymetry". From the results of...
Article
Full-text available
Great efforts are presently taken in the scientific community to develop computerized and (fully) automated image processing methods allowing for an efficient and automatic monitoring of sea birds and marine mammals in ever-growing amounts of aerial imagery. Currently the major part of the processing, however, is still conducted by especially train...
Article
Full-text available
UAS become a very valuable tool for coastal morphology. Not only for mapping but also for change detection and a better understanding of processes along and across the shore. This contribution investigates the possibilities of UAS to determine the water depth in clear shallow waters by means of the so called "photo bathymetry". From the results of...
Article
Reconstruction and maintenance work in historical buildings such as churches requires detailed and accurate information about them, but it can be difficult and expensive to acquire such data efficiently. The combination of terrestrial Lidar and UAS-based photogrammetry provides an adequate approach for gathering a full model of the outside of a chu...
Research
Full-text available
In this contribution the possibility to combine terrestrial laser scanner (TLS) measurements and UAS photogrammetry for the detailed description and high quality surveying of a cultural monument will be illustrated by the example of the Cathedral of St. Nicholas in the city of Greifswald. Due to the different nature of UAS photogrammetry and TLS wa...
Conference Paper
Full-text available
In this contribution the possibility to combine terrestrial laser scanner (TLS) measurements and UAS photogrammetry for the detailed description and high quality surveying of a cultural monument will be illustrated by the example of the Cathedral of St. Nicholas in the city of Greifswald. Due to the different nature of UAS photogrammetry and TLS wa...
Conference Paper
Full-text available
The aim of gaining a better understanding of ecosystems and the processes in nature accentuates the need for observing exactly these processes with a higher temporal and spatial resolution. In the field of environmental monitoring, an inexpensive and field applicable imaging technique to derive three-dimensional information about plants and vegetat...
Conference Paper
Full-text available
Zusammenfassung: Die Erfassung von Wildtieren im Wald ist nicht trivial. In dem Beitrag wird untersucht, ob Thermalaufnahmen eine Möglichkeit darstellen und welche Rahmenbe-dingungen dafür erfüllt sein müssen. Dazu wurde am 14.04.2012 ein Thermaler Bildflug mit einem GSD von 22 cm / Pixel durchgeführt. Umfangreiche Referenzmessungen an verschie-den...
Conference Paper
Full-text available
The accurate determination of the height of agricultural crops helps to predict yield, biomass etc. These relationships are of great importance not only for crop production but also in grassland management, because the available biomass and food quality are valuable information. However there is no cost efficient and automatic system for the determ...
Article
Full-text available
Despite the beneficial effects of reeds on abiotic environmental resources (by trapping sediments) their tendency to form near-monocultures with only a small number of accompanying species limits biodiversity at the landscape scale. This is a problem in some habitats such as coastal saltmarsh grasslands which have the potential to host a range of r...
Conference Paper
Full-text available
The main focus of the paper is a comparative study in which we have investigated, whether automatically generated digital surface models (DSM) obtained from unmanned aerial systems (UAS) imagery are comparable with DSM obtained from terrestrial laser scanning (TLS). The research is conducted at a pilot dike for coastal engineering. The effort and t...
Conference Paper
Full-text available
The standard procedure to count birds is a manual one. However a manual bird count is a time consuming and cumbersome process, requiring several people going from nest to nest counting the birds and the clutches. High resolution imagery, generated with a UAS (Unmanned Aircraft System) offer an interesting alternative. Experiences and results of UAS...
Article
Full-text available
Numerous unmanned aerial systems (UAS) are currently flooding the market. For the most diverse applications UAVs are special designed and used. Micro and mini UAS (maximum take-off weight up to 5 kg) are of particular interest, because legal restrictions are still manageable but also the payload capacities are sufficient for many imaging sensors. C...
Conference Paper
Full-text available
Despite the numerous beneficial effects of reeds on the abiotic environmental resources, their tendency to form unique, monocultural stands associated with only a small numberof accompanying species limits biodiversity at the landscape scale. This is a problem in specialist habitat such as coastal salt grasslands which have the potential to host a...
Article
Full-text available
BRDF is a common problem in remote sensing and also in oblique photogrammetry. Common approaches of BRDF-measurement with a field goniometer are costly and rather cumbersome. UAV's may offer an interesting alternative by using a special flight pattern of oblique and converging images. The main part of this paper is the description of a photogrammet...
Article
Full-text available
Due to regulations micro-UAV's with a maximum take-off weight of > 5kg are commonly bound to applications within the line of sight. An extension of the ground coverage is possible by using a set of oblique cameras. The development of such a multi camera system with a total weight of 1 kg under photogrammetric aspects is quite challenging. The intro...
Article
Full-text available
This paper focuses on the development of a concept for determining the exterior orientation of an Unmanned Aerial Vehicle (UAV) using a terrestrial system with target tracking tacheometer, a reflector and additional coloured markers on board of the UAV. Two variants - a one-point solution and a stereo-solution - will be presented. All basic geometr...
Article
This study presents an approach for chlorophyll content determination of small shallow water bodies (kettle holes) from hyperspectral airborne ROSIS and HyMap data (acquired on 15 May and 29 July 2008 respectively). Investigated field and airborne spectra for almost all kettle holes do not correspond to each other due to differences in ground sampl...
Article
Full-text available
An expansion of offshore wind energy production could lead to a significant loss of wintering and staging habitats for seabirds. To assess the impact of wind farms before, during and after their construction, the standard investigation concept of the Federal Maritime and Hydrographic Agency (BSH) currently recommends ship- and aircraft-based bird s...
Chapter
Since the beginning of the 1990s, modern agriculture and farming has changed dramatically. Agriculture has become a high-tech industry. With the possibility for locating agricultural machinery in the field using satellite positioning technologies (Global Navigation Satellite Systems, GNSS) and the increasing availability of geographic information i...
Article
Full-text available
More medium format airborne camera systems are in operation globally than the well recognised large format digital imaging systems. EuroSDR has initiated a digital medium format project to investigate the market, the geometric and radiometric potentials as well as current trends and future developments. After a categorisation of small and medium fo...
Article
Full-text available
The report describes digital medium format cameras as professional systems, used for airborne mapping applications. In the last two years the term "medium format" does not stand for a single camera, equipped with a CCD-chip fitting in the former 6 * 6 em medium format camera bodies anymore. The newly introduced "medium format" systems from Microsof...
Article
Full-text available
Small inland water bodies, such as kettle holes, are subject to pollution, drainage and structural alteration by intensive land-use practices. This study analyses the ability of field spectroscopy to sense the changes of biomass concentration in small water bodies resulting from agricultural nutrient input. Based on in-situ water sampling and refle...
Article
Full-text available
Digital airborne photogrammetric imaging systems are operational and already have substituted the analogue mapping cameras in many countries and applications. The high potential of digital airborne imaging was already evaluated through several empirical tests. Compared to the former analogue mapping cameras, which all provide standard analogue imag...
Conference Paper
Full-text available
Zusammenhänge zwischen spektralen Eigenschaften der Böden und ih- ren Gehalten an organischem Kohlenstoff (Corg) wurden mit vier Methoden unter- sucht. Messungen im Labor (Chromameter von Konica-Minolta, 400-700 nm) und im Feld (HandySpec Field, Tec5 AG, 360-1.000 nm) ergaben Korrelationen mit R 2 = 0,63*** bzw. 0,52*** (n = 133). Aus Grauwerten ei...
Article
Full-text available
Because of the intuitive human perception of the oblique view, photogrammetrists' attention has recently returned to oblique images. The demand for oblique imagery has been notably pushed by digital representations of the globe such as Microsoft's Virtual Earth and by the development of special GIS viewers including those by Pictometry and MultiVis...
Article
Full-text available
In Europe more than 10.000 dual frequency iTC Starfire GPS-receivers were sold in recent years. These GPS-receivers are mainly used for parallel tracking and autosteering of modern tractors and combine harvesters. The recorded GPS-data also includes precise height information which can be used for the generation of high accuracy digital terrain mod...
Article
Full-text available
Micro-UAVs (Unmanned-Airborne-Vehicles or drones) with a total weight below 5 kg are interesting alternative carriers for agricultural and forestry applications. Compared to standard airborne aerial surveys UAVs are much more flexible and weather independent. As a result micro-UAV surveys will pave the way for affordable, current and accurate geo-i...
Article
Micro-UAV's (Unmanned-Airborne-Vehicles or drohnes) with a total weight below 5 kg are interesting alternative carriers for agricultural and forestry applications. Compared to standard airborne aerial surveys UAVs are much more flexible and weather independent. As a result micro-UAV's surveys will pave the way to affordable, current and accurate ge...
Conference Paper
Full-text available
Zusammenfassung: Photogrammetrische Systeme mit GPS/INS stoßen immer mehr in Onli-ne-Anwendungen vor. Allerdings liegen die erzielten Genauigkeiten im Objektraum aus ver-schiedenen Gründen deutlich unter den theoretischen Möglichkeiten. In dem Beitrag werden verschiedenste Einzelfaktoren identifiziert und deren Einfluss im Rahmen von Testflügen sys...
Article
Full-text available
The city of Rostock in East Germany has undergone drastic changes in the last 15 years since the reunification of Germany. To cover the spatial extent of the urban developments and the changes in land use different remote sensing sensors and image analysis techniques were used. The land use of 1989 and 1995 was determined at a 1:50.000 scale based...
Article
Full-text available
Beside high end digital imaging systems which will replace standard photogrammetric cameras in the future, a large number of "low-cost" airborne systems were developed in the last years. The demand for current digital data of "hot spots" in urban areas and small communities for various purposes is strongly increasing. The system PFIFF, a digital ai...
Article
Full-text available
Beside high end digital imaging systems which will replace standard photogrammetric cameras in the future, a large number of "low-cost" airborne systems were developed in the last years. The system PFIFF, a digital airborne remote sensing system developed by the author, is described in detail with special respect to demonstrate the photogrammetric...

Projects

Projects (4)
Project
To design, develop and test a fully-automated data driven platform for variable rate fertigation (VRFI). Objectives: •Collect data on soil, crop, and topography attributes. •Develop recommendations for VRF of N, P and K and water use for irrigation using advanced machine learning, data fusion, geostatistics and decision support tools. •Develop a fully-automated ICT platform for data transfer, data storage, data processing and management, accounting for data stewardship and data standardisation. •Validate the fully-automated ICT platform for VRFI in commercial fields. •Apply cutting edge life cycle analysis (LCA) and socio-economic tools to evaluate the environmental and economic performance of the developed solution. •To communicate with key stakeholder groups to promote adoption of the combined solution. Hypothesis: implementation of a fully automated, data-driven platform for VRFI increases crop yield, and reduces environmental footprint by reducing the amount of N, P and water use for irrigation.