Users’ Assessment of Orthoimage Photometric Quality for Visual Interpretation of Agricultural Fields

Land cover identification and area quantification are key aspects of implementing the European Common Agriculture Policy. Rightfulness of support provided to farmers is monitored using the Land Parcel Identification System (LPIS), with land cover identification performed by photointerpretation. While the geometric orthoimage quality required for correct photointerpretation is well understood, little is known about the photometric quality needed for LPIS applications. This paper analyzes the orthoimage quality characteristics chosen by authors as being most suitable for visual identification of agricultural fields. We designed a survey to assess users’ preferred brightness and contrast ranges for orthoimages used for LPIS purposes. Survey questions also tested the influence of a background color on the preferred orthoimage brightness and contrast, the preferred orthoimage format and color composite, assessments of orthoimages with shadowed areas, appreciation of image enhancements and, finally, consistency of individuals’ preferred brightness and contrast settings across multiple sample images. We find that image appreciation is stable at the individual level, but preferences do vary across respondents. We therefore recommend that LPIS operators be enabled to personalize photometric settings, such as brightness and contrast values, and to choose the displayed band combination from at least four spectral bands.JRC.H.4-Monitoring Agricultural Resource

Annual Highlights of Results from the International Space Station October 1, 2017 - October 1, 2018

The International Space Station (ISS) is a unique place a convergence of science, technology and human innovation that demonstrates new technologies and makes research breakthroughs that cannot be accomplished on Earth. As an international laboratory for scientific research in microgravity, the space stations international crew lives and works while traveling at a speed of about five miles per second as they make new discoveries in the disciplines of biology and biotechnology, Earth and space science, human research, physical science, educational activities, and technology development and demonstrations

Detection of the forest disturbance using UAV multispectral photogrammetry

Epidemic (calamitous) overpopulations of bark beetles (Scolytinae Latreille, 1804) caused by climate change and inappropriate tree species composition currently have the most negative impacts on the development of Europe's mixed and boreal forests. Epidemic overpopulations can significantly undermine forest health and cause economic losses. It is therefore essential to use appropriate methods for early detection of bark beetle disturbance. Multispectral remote sensing (RS) methods using unmanned aerial systems (UAS) represent a new option for contactless landscape monitoring providing quantitative information on vegetation health with high spatiotemporal resolution and therefore appear to be suitable for early detection of disturbance. The thesis focused on the validation of the use of UAS multispectral photogrammetry and image classification methods for the detection of individual forest disturbance stages caused by the spruce bark beetle (Ips typographus Linnaeus, 1758) at the level of individual trees for the study of disturbance dynamics. In this dissertation, all important aspects of detection were elaborated: analysis of the suitability of spectral bands for disturbance detection, radiometric calibration of multispectral cameras, automated segmentation of individual canopies from...V současné době nejvíce negativně ovlivňují vývoj smíšených a boreálních lesů Evropy epidemické (kalamitní) přemnožení kůrovců (Scolytinae Latreille, 1804) vlivem klimatické změny a nevhodné skladby dřevin, která mohou výrazně narušit zdravotní stav lesů a způsobit ekonomické ztráty. Proto je nezbytné použít vhodné metody pro včasnou detekci kůrovcové disturbance. Metody multispektrálního dálkového průzkumu země (DPZ) pomocí bezpilotních leteckých systémů (UAS) představují novou možnost bezkontaktního monitoringu krajiny poskytující kvantitativní informaci o zdravotním stavu vegetace s vysokým časoprostorovým rozlišením, proto se jeví jako vhodné i pro včasnou detekci disturbance. Disertační práce se zaměřila na ověření využití metod UAS multispektrální fotogrammetrie a klasifikace obrazu pro detekci disturbance lesa způsobené lýkožroutem smrkovým (Ips typographus Linnaeus, 1758) na úrovni jednotlivých stromů s rozlišením jednotlivých fází napadení pro studium dynamiky disturbance. V disertační práci byly rozpracovány všechny důležité aspekty detekce: analýza vhodnosti spektrálních pásem pro detekci disturbance, radiometrická kalibrace multispektrálních kamer, automatizovaná segmentace jednotlivých korun z fotogrammetrického mračna bodů (PPC) a klasifikace fází disturbance na úrovni jednotlivých...Department of Physical Geography and GeoecologyKatedra fyzické geografie a geoekologiePřírodovědecká fakultaFaculty of Scienc

Materials for large-area electronics: characterization of pentacene and graphene thin films by ac transport, Raman spectroscopy, and optics

This dissertation explores techniques for fabricating and characterizing two classes of novel materials which may be useful for large-area electronics applications: organic semiconductors and graphene. Organic semiconductors show promise for large-area electronics because of their low cost, compatibility with a variety of substrates, and relative ease of fabricating and patterning thin-film transistors (TFTs). Nearly all published work has focused on the dc electronic transport properties of these materials, rather than their ac behavior, which could be affected by their polycrystalline, granular structure. To address this, I have constructed a model of organic TFTs based on lossy transmission lines, and determined the relationship between the film conductivity and the overall device behavior for a bottom-contacted TFT. I apply this transmission-line framework to interpret my experiments on pentacene TFTs designed in a special long-channel geometry to hasten the onset of high-frequency effects. The experiments reveal an intrinsic frequency-dependent conductivity of polycrystalline pentacene, which can be understood within the context of the universal dielectric response model of ac conduction in disordered solids. The results are important for establishing practical limits on pentacene's ac performance. Graphene is a two-dimensional crystalline form of carbon, with a remarkably simple structure. It is a gapless semiconductor with an extremely high mobility and very high optical transparency, attracting great interest both for its possible uses as a replacement for silicon and as a transparent conducting material. I have synthesized large-area films of graphene via atmospheric-pressure chemical vapor deposition (CVD) on copper substrates, adapting a low-pressure CVD method previously reported to produce exclusively monolayer graphene films. I have transferred the graphene films to insulating SiO2, and characterized them using optical transparency, Raman spectroscopy, and atomic-force microscopy, observing significant differences from the measured properties of widely studied mechanically-exfoliated graphene. I analyze the strengths and weaknesses of these three techniques for distinguishing films of different layer number, and relate them to uncertainties in the known properties of one- and few-layer graphene. I conclude that atmospheric-pressure CVD of graphene on copper produces significant areas of multilayer, rotationally-misoriented graphene, in a significant departure from results on low-pressure CVD of graphene on copper

Multitemporal assessment of crop parameters using multisensorial flying platforms

UAV sensors suitable for precision farming (Sony NEX-5n RGB camera; Canon Powershot modified to infrared sensitivity; MCA6 Tetracam; UAV spectrometer) were compared over differently treated grassland. The high resolution infrared and RGB camera allows spatial analysis of vegetation cover while the UAV spectrometer enables detailed analysis of spectral reflectance at single points. The high spatial and six-band spectral resolution of the MCA6 combines the opportunities of spatial and spectral analysis, but requires huge calibration efforts to acquire reliable data. All investigated systems were able to provide useful information in different distinct research areas of interest in the spatial or spectral domain. The UAV spectrometer was further used to assess multiangular reflectance patterns of wheat. By flying the UAV in a hemispherical path and directing the spectrometer towards the center of this hemisphere, the system acts like a large goniometer. Other than ground based goniometers, this novel method allows huge diameters without any need for infrastructures on the ground. Our experimental results shows good agreement with models and other goniometers, proving the approach valid. UAVs are capable of providing airborne data with a high spatial and temporal resolution due to their flexible and easy use. This was demonstrated in a two year survey. A high resolution RGB camera was flown every week over experimental plots of barley. From the RGB imagery a time series of the barley development was created using the color values. From this analysis we could track differences in the growth of multiple seeding densities and identify events of plant development such as ear pushing. These results lead towards promising practical applications that could be used in breeding for the phenotyping of crop varieties or in the scope of precision farming. With the advent of high endurance UAVs such as airships and the development of better light weight sensors, an exciting future for remote sensing from UAV in agriculture is expected