
G. J. GrenzdörfferUniversity of Rostock · Faculty of Agricultural and Environmental Sciences
G. J. Grenzdörffer
Dr.-Ing.
About
70
Publications
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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
Education
April 1994 - December 2001
August 1990 - May 1991
October 1987 - February 1994
Publications
Publications (70)
Cultivation of cover crops is a valuable practice in sustainable agriculture. In cover crop management, the method of desiccation is an important consideration, and one widely used method for this is the application of glyphosate. With use of glyphosate likely to be banned soon in Europe, the purpose of this study was to evaluate the herbicidal eff...
Zusammenfassung: Für ein vollständiges Bild der nächtlichen Lichtbelastung (≈Lichtverschmutzung) einer Kommune, stehen verschiedene Fern-und Naherkundungsinstrumente zur Verfügung. Dabei liefern unterschiedliche Beobachtungsebenen, von der Satellitenperspektive bis zur stationären Kamera, unterschiedliche Ergebnisse für verschiedene Zwecke. Die Sat...
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...
Seit einigen Jahren versprechen Drohnen für einen weiteren Durchbruch des Precision Farming zu sorgen, um Erträge zu steigern und gleichzeitig Wasser- und Nahrungsmittelkrisen zu lösen. Auch wird der landwirtschaftliche Sektor in vielen Studien als großer Zukunftsmarkt für Drohnen gehandelt. Fast jeder zehnte Landwirt in Deutschland setzt auf seine...
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.
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...
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...
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...
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...
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...
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...
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...
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....
Feasility study of the use of multispectral and multisesnoral drones for the quantitative measurement of selected vegetation properties of tidal vegetation
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...
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...
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.
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...
The poster was presented at 149th annual meeting of the German Ornithological Society in 2016.
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...
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...
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...
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...
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...
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...
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...
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...
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...
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...
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...
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...
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...
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...
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...
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...
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...
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...
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...
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...
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...
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...
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...
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...
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...
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...
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...
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...
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...
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...
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...
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...
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...
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...
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...