Spatial Fluorescence patterns in a heterogeneous agriculture landscapeMaria Matveeva1, Patrick Ra... more Spatial Fluorescence patterns in a heterogeneous agriculture landscapeMaria Matveeva1, Patrick Rademske1, Alexander Damm2, Cosimo Brogi3, Guido Waldhoff4, and Uwe Rascher11 Institute of Bio- and Geosciences, IBG-2: Plant Sciences, Forschungszentrum Jülich GmbH, Leo-Brandt-Str., 52425 Jülich, Germany2 Remote Sensing Laboratories, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland3 Institute of Bio- and Geosciences, IBG-3: Agrosphere, Forschungszentrum Jülich GmbH, Leo-Brandt-Str., 52425 Jülich, Germany4 Institute of Geography, University of Cologne, Albertus-Magnus-Platz , D-50923 Cologne, GermanySun induced fluorescence (F) is a remote sensing signal that is emitted from the core of the photosynthetic machinery. The fluorescence signal has the potential to quantify the actual rate of photosynthesis and is closely related to vegetation stress and reflects functional limitations of photosynthetic carbon gain. F is a rather weak signal, but can be measured in the s...
There are strong interactions between soil properties, plant growth and atmosphere. We use sun-in... more There are strong interactions between soil properties, plant growth and atmosphere. We use sun-induced Fluorescence (F) to obtain information about the plant physiological status that can be linked to soil and atmospheric properties, improving our understanding of energy and matter flows. F is a remote sensing signal closely related to the actual rate of photosynthesis and vegetation stress. It reflects functional limitations of the photosynthetic carbon gain and can be measured in solar and atmospheric absorption lines using high performance spectrometers.We have collected data for spatial analyses using the high performance imaging spectrometer HyPlant, measuring in wavelength ranges 400 – 2500 nm and 670 – 780 nm with a spectral resolution of 0.26 nm. Data were recorded with a spatial resolution of 3 m per pixel for the entire region (ca. 14×14 km2) and with a 1 m resolution for the Selhausen area (ca. 1.5×5 km2) that was better characterized, in particular in terms of the land u...
Variations in photosynthesis that are not related to greenness of vegetation cannot be measured b... more Variations in photosynthesis that are not related to greenness of vegetation cannot be measured by traditional optical remote sensing techniques and still cause substantial uncertainties in predicting photosynthetic CO2 uptake rates and monitoring plant stress. Several activities were underway to evaluate the sun-induced fluorescence signal on the ground and on a coarse spatial scale using space-borne imaging spectrometers. Intermediate-scale observations using airborne-based imaging spectroscopy, which are critical to bridge the existing gap between small-scale field studies and global observations, are still insufficient. Here we present validated maps of sun-induced fluorescence in that critical, intermediate spatial resolution, employing the novel airborne imaging spectrometer HyPlant. HyPlant has an unprecedented spectral resolution, which allows for the first time quantifying sun-induced fluorescence fluxes in physical units according to the Fraunhofer Line Depth Principle that exploits solar and atmospheric absorption bands. Fluorescence maps show a large spatial variability between different vegetation types, which are not detected with classical remote sensing approaches.It could be shown that different crop types largely differ in emitting fluorescence that is related to the activity of the photosynthetic machinery and allows separating annual and perennial C3 and C4 crops and grasses. Additionally, it could be shown in different case studies that the two peak feature of sun-induced fluorescence emission is related to (i) the total absorbed radiation by photosynthetically active chlorophyll (far-RED peak) and (ii) the functional status of photosynthesis and vegetation stress (RED peak). Thus, the dynamic changes of the two peaks of fluorescence code for structural and functional variability within canopies. Sun-induced fluorescence thus can be used to better understand and to monitor the dynamic adaptations of the photosynthetic machinery of plants to the ever changing environmental conditions. Sun-induced fluorescence thus constitutes a novel and highly relevant remote sensing signal to understand and manage our natural and managed ecosystems in times of global change and to facilitate a sustainable use of plants and plant resources
Plasma-surface interactions in fusion devices represent a critical issue for the design and opera... more Plasma-surface interactions in fusion devices represent a critical issue for the design and operation of diagnostic systems based on transmission of light signals from plasma where metallic mirrors will be used as first plasma-viewing elements. In this work, the behavior of metallic mirrors is investigated with respect to the influence of plasma-induced changes of surface morphology and composition on the surface reflectivity. The work is based on the series of dedicated experiments performed in tokamaks TEXTOR and DIII-D, in which pre-characterized metallic mirrors were exposed during the plasma operation (TEXTOR) and during the thermo-oxidative wall conditioning (DIII-D). The morphology, composition and optical properties of the mirror surfaces are analyzed post-mortem. To understand the observed surface modifications, ion-surface interactions are modelled with the SDTrimSP code. The processes responsible for modifications of the surface morphology and composition under energetic ...
The ability to investigate the Earth’s environment will be greatly improved by hyperspectral sate... more The ability to investigate the Earth’s environment will be greatly improved by hyperspectral satellite data. The FLuorescence EXplorer (FLEX) will be the first hyperspectral mission designed to monitor the photosynthetic activity of the terrestrial vegetation layer by using a completely novel technique measuring the sun-induced chlorophyll fluorescence (SIF) signal that originates from the core of the photosynthetic machinery. In preparation of the upcoming FLEX satellite mission that will be launched in 2022 a large field campaign, namely FLEXSense, was conducted in summer 2018 including representative study sites at several locations in middle and south Europe as well as North America.During the different/various field activities, airborne data was acquired with the hyperspectral airborne imager HyPlant, whichthat consists of two sensor heads. The DUAL module is a line-imaging push-broom sensor, which providinges contiguous spectral information from 370 to 2500 nm. The vegetationc...
When plants absorb light, not all energy is converted by photosynthesis, but excess energy is rel... more When plants absorb light, not all energy is converted by photosynthesis, but excess energy is released as heat or emitted as sun-induced chlorophyll fluorescence (F). This signal, related to the photosynthetic efficiency of plants, has been intensively studied and measured from ground, airborne and satellite. However, retrieving sun-induced fluorescence (F) from remote sensing data is challenging because accurate modeling of atmospheric influences is required.. The advent of the airborne imaging spectrometer HyPlant made possible to produce F maps in high-spatial resolution (1-3 meters), which is a valuable tool to better understand F at relevant ecosystem scale. Currently, two different algorithms are used routinely to retrieve red and far-red F from HyPlant. Both methods are based on the O 2 absorption bands, but while iFLD method employs a semi-empirical atmospheric correction (i.e., bare-soils), the SFM makes use of a physically-based atmospheric modeling (MODTRAN5 code). A comm...
Regional mapping of Fluorescence in a heterogeneous agriculture landscapeMaria Matveeva1, Patrick... more Regional mapping of Fluorescence in a heterogeneous agriculture landscapeMaria Matveeva1, Patrick Rademske1, Alexander Damm2, Cosimo Brogi3, Wolfgang Korres4, and Uwe Rascher11 Institute of Bio- and Geosciences, IBG-2: Plant Sciences, Forschungszentrum Jülich GmbH, Leo-Brandt-Str., 52425 Jülich, Germany2 Remote Sensing Laboratories, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland3 Institute of Bio- and Geosciences, IBG-3: Agrosphere, Forschungszentrum Jülich GmbH, Leo-Brandt-Str., 52425 Jülich, Germany4 Institute of Geography, University of Cologne, Albertus-Magnus-Platz , D-50923 Cologne, GermanyThe increased interest of the scientific community to the remote sensing of sun-induced chlorophyll fluorescence (F) leads to a large number of fruitful and interesting experiments on the field scale. On the other side, satellite data became available, from which fluorescence on the global scale can be derived. However, it is still an open question, how representativ...
Due to their high-quality routine measurement programme, ICOS sites lend themselves as anchors fo... more Due to their high-quality routine measurement programme, ICOS sites lend themselves as anchors for additional experiments. As an example, we describe the CloudRoots campaign near the agricultural site Selhausen (DE-RuS) in spring 2018.Little is known about the two-way feedback between stomatal control (controlling the partitioning of energy into sensible and latent heat) and cloud development (affecting potential evapotranspiration). Coupled models of the soil-vegetation-boundary layer continuum have the potential to explain this, but their calculations are only as robust as the data used to parameterize or validate the model. For observations and modelling, the challenge is in interconnecting processes at leaf level to the physics of turbulence and clouds.We temporarily amend the existing radiation, flux and soil dynamics/respiration measurements of the ICOS site by scintillometry, sap-flow and leaf-level flux measurements, vertical profiles and isotope measurements. Scintillometer...
Non-invasive geophysical fixed-boom multi-coil electromagnetic induction (EMI) instruments return... more Non-invasive geophysical fixed-boom multi-coil electromagnetic induction (EMI) instruments return apparent electrical conductivity (ECa) values that depend on subsurface soil properties. Using different transmitter-receiver coil separations and orientations, ECa values of different depths of investigation (DOI) are obtained. After calibration, the quantitative EMI data are inverted to obtain electrical conductivity (σ) changes over depth assuming a layered subsurface model. Airborne hyperspectral measurements are used to estimate plant performance and growth, however, the top- and subsoil structural changes influencing plant performance and growth is often ignored. Here, we have investigated the origin of observed patterns in sun-induced fluorescence data by performing quantitative large-scale EMI measurements and quantitative inversions. The fixed-boom multi-coil EMI ECa data of nine coil configurations indicated spatial patterns due to buried paleo-river channels. After inversion,...
Photosynthesis dynamically adapts to changing environmental conditions. Extreme environmental con... more Photosynthesis dynamically adapts to changing environmental conditions. Extreme environmental conditions such as high temperature and water limitation directly reflect in the photosynthetic performance as vegetation stress. To monitor photosynthesis dynamics at large vegetation scales, indicators of stresses in vegetation extracted by non-invasive techniques can be used.Spectral reflectance indices such as NDVI and PRI have been tested to provide rapid and non-invasive estimation of photosynthesis at regional scales. Unfortunately, these indices lack sensitivity to short-term vegetation physiological changes. Alternatively, a passive retrieval of sun-induced chlorophyll fluorescence (SIF) using high performance imaging spectroscopy has been suggested. SIF emission is closely related to the status of photosynthesis and therefore has the potential to track adaptation of this process to changes in environmental conditions and plant status. Although SIF emission represents a weak signal in comparison to the reflected radiation, recent research provides evidence that SIF can be measured by exploiting solar and atmospheric absorption lines using high performance spectrometers.In this contribution, we present the design and first results of an experiment that aimed to evaluate the capability of the new remote observable SIF and common reflectance based indices to detect plant stress. In the experiment, carried out in June and July 2014 in Latisana (Italy), we treated homogeneous lawn plots to provoke different level of stress in plants. In particular, we applied the herbicide (Dicuran) in different concentrations to four plots, three other plots were treated with the anti-transpirant Vaporgard; while three remaining plots were not treated and used as control. Diurnal variations in SIF and surface reflectance were evaluated for period of two weeks, using the high performance imaging spectrometer HyPlant. HyPlant is a dedicated fluorescence spectrometer and allows measuring radiance in the wavelength range between 400 nm and 2500 nm with a high spectral resolution of 0.26 nm between 670 nm and 780 nm. Data was recorded for spatial resolution of 1 meter per pixel.Airborne data was calibrated and validated using high resolution top of canopy measurements of reflectance and SIF. Vegetation indices and SIF were calculated for treated and non-treated areas and compared with corresponding ground measurements. Additional measurements of CO2 and H2O fluxes using chambers and an eddy covariance tower to monitor photosynthetic activity were performed.First results show contrasting responses of emitted SIF and vegetation indices for plant stress: SIF strongly increased after the treatment with Dicuran followed by a slow decrease down to the initial values. The Meris Terrestrial Chlorophyll Index (MTCI) showed a clear decrease after the herbicide treatment. We conclude that SIF is a promising new observable sensitive to plant stress which provides complementary information to commonly used remote observables origin form reflectance spectroscopy. We suggest a combined use of SIF and reflectance spectroscopy to establish reliable approaches for rapid, early, and non-invasive plant stress detection
Photosynthesis is the most important exchange process of CO2 between the atmosphere and the land-... more Photosynthesis is the most important exchange process of CO2 between the atmosphere and the land-surface. Spatial and temporal patterns of photosynthesis depend on dynamic plant-specific adaptation strategies to highly variable environmental conditions e.g. light, water, and nutrient availability. Therefore, an accurate quantification of photosynthetic CO2 uptake, commonly referred to as gross primary productivity (GPP), is a key parameter to monitor plant performance.Hyperspectral reflectance techniques often failed to quantify actual photosynthetic light use efficiency (LUE) and only allow measuring pigment content and canopy structure. One promising approach for obtaining global estimates of plant photosynthesis is the use of Sun Induced Chlorophyll Fluorescence (SIF). SIF has been proposed as a direct indicator of plant photosynthesis, and several studies have demonstrated its relationship with vegetation functioning at leaf and canopy level.In this presentation we summarize the...
This data set contains ground-based apparent electrical conductivity (ECa) of eight depth ranges ... more This data set contains ground-based apparent electrical conductivity (ECa) of eight depth ranges of investigation. These were inverted for a three-layer electrical conductivity model. Five .dat files contain the depth-specific inverted electrical conductivity and respective layer thicknesses. Three dat-files correspond to airborne plant performance data. Additionally, six figures show the linear regressions between soil information (electrical conductivity property) and plant performance and one video shows the quasi-3D EMI inversion results.
IGARSS 2020 - 2020 IEEE International Geoscience and Remote Sensing Symposium, 2020
In summer 2019 the SARSense campaign was held in Jülich, Germany, to provide insights into the po... more In summer 2019 the SARSense campaign was held in Jülich, Germany, to provide insights into the potentials and specifications of the ESA Copernicus candidate mission ROSE-L (Radar Observation System for Europe). ROSE-L will consist of two satellites that carry a polarimetric L-band SAR. Since the L-band signal can penetrate through many natural materials such as vegetation, dry snow and ice, the mission will provide additional information that cannot be gathered by the Copernicus Sentinel-1 C-band SAR mission. The overall objective of the SARSense 2019 campaign is to analyze the mission design concerning its potential for agricultural monitoring services including target applications such as soil moisture monitoring, irrigation management, crop type discrimination, food security and precision farming. The SARSense in situ measurements of soil moisture, soil temperature, vegetation properties, UAS-based multispectral and thermal mapping, as well as the airborne SAR observations are pr...
The SARSense campaign in the Jülich area (Germany) in summer 2019 was performed to support the ES... more The SARSense campaign in the Jülich area (Germany) in summer 2019 was performed to support the ESA Copernicus high priority mission ROSE-L. Airborne SAR signals in C-and L-band, drone imagery, in situ soil and plant parameters, as well as biophysical variables in the lab were measured to provide a comprehensive data set to study details of the mission design for agricultural applications. Although an in depth analysis will be performed soon, the preliminary outcome of the dry summer example campaign is as follows: An L-band SAR monitoring in the Copernicus program will provide an added value to the existing C-band capacities of Sentinel-1 (A/B). Simultaneous C-and L-band observations may help to disentangle the different processes in the plant and the soil. Single frequency observations may tend to be misinterpreted.
Vilà-Guerau de Arellano et al.: CloudRoots depend on the scale where the measurement were taken a... more Vilà-Guerau de Arellano et al.: CloudRoots depend on the scale where the measurement were taken and on the plant growing stage.
The HyPlant imaging spectrometer is a high-performance airborne instrument consisting of two sens... more The HyPlant imaging spectrometer is a high-performance airborne instrument consisting of two sensor modules. The DUAL module records hyperspectral data in the spectral range from 400–2500 nm, which is useful to derive biochemical and structural plant properties. In parallel, the FLUO module acquires data in the red and near infrared range (670–780 nm), with a distinctly higher spectral sampling interval and finer spectral resolution. The technical specifications of HyPlant FLUO allow for the retrieval of sun-induced chlorophyll fluorescence (SIF), a small signal emitted by plants, which is directly linked to their photosynthetic efficiency. The combined use of both HyPlant modules opens up new opportunities in plant science. The processing of HyPlant image data, however, is a rather complex procedure, and, especially for the FLUO module, a precise characterization and calibration of the sensor is of utmost importance. The presented study gives an overview of this unique high-perform...
Soil structures at depth obtained by quantitative 3D electromagnetic induction data inversions ... more Soil structures at depth obtained by quantitative 3D electromagnetic induction data inversions not by apparent electrical conductivity maps Deeper subsoil characteristics correlate with airborne sun-induced fluorescence data indicating soil moisture effects on plant performance Quantitative inverted electrical conductivity model together with plant data help to inform and improve soil-vegetation-atmosphere models
Spatial Fluorescence patterns in a heterogeneous agriculture landscapeMaria Matveeva1, Patrick Ra... more Spatial Fluorescence patterns in a heterogeneous agriculture landscapeMaria Matveeva1, Patrick Rademske1, Alexander Damm2, Cosimo Brogi3, Guido Waldhoff4, and Uwe Rascher11 Institute of Bio- and Geosciences, IBG-2: Plant Sciences, Forschungszentrum Jülich GmbH, Leo-Brandt-Str., 52425 Jülich, Germany2 Remote Sensing Laboratories, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland3 Institute of Bio- and Geosciences, IBG-3: Agrosphere, Forschungszentrum Jülich GmbH, Leo-Brandt-Str., 52425 Jülich, Germany4 Institute of Geography, University of Cologne, Albertus-Magnus-Platz , D-50923 Cologne, GermanySun induced fluorescence (F) is a remote sensing signal that is emitted from the core of the photosynthetic machinery. The fluorescence signal has the potential to quantify the actual rate of photosynthesis and is closely related to vegetation stress and reflects functional limitations of photosynthetic carbon gain. F is a rather weak signal, but can be measured in the s...
There are strong interactions between soil properties, plant growth and atmosphere. We use sun-in... more There are strong interactions between soil properties, plant growth and atmosphere. We use sun-induced Fluorescence (F) to obtain information about the plant physiological status that can be linked to soil and atmospheric properties, improving our understanding of energy and matter flows. F is a remote sensing signal closely related to the actual rate of photosynthesis and vegetation stress. It reflects functional limitations of the photosynthetic carbon gain and can be measured in solar and atmospheric absorption lines using high performance spectrometers.We have collected data for spatial analyses using the high performance imaging spectrometer HyPlant, measuring in wavelength ranges 400 – 2500 nm and 670 – 780 nm with a spectral resolution of 0.26 nm. Data were recorded with a spatial resolution of 3 m per pixel for the entire region (ca. 14×14 km2) and with a 1 m resolution for the Selhausen area (ca. 1.5×5 km2) that was better characterized, in particular in terms of the land u...
Variations in photosynthesis that are not related to greenness of vegetation cannot be measured b... more Variations in photosynthesis that are not related to greenness of vegetation cannot be measured by traditional optical remote sensing techniques and still cause substantial uncertainties in predicting photosynthetic CO2 uptake rates and monitoring plant stress. Several activities were underway to evaluate the sun-induced fluorescence signal on the ground and on a coarse spatial scale using space-borne imaging spectrometers. Intermediate-scale observations using airborne-based imaging spectroscopy, which are critical to bridge the existing gap between small-scale field studies and global observations, are still insufficient. Here we present validated maps of sun-induced fluorescence in that critical, intermediate spatial resolution, employing the novel airborne imaging spectrometer HyPlant. HyPlant has an unprecedented spectral resolution, which allows for the first time quantifying sun-induced fluorescence fluxes in physical units according to the Fraunhofer Line Depth Principle that exploits solar and atmospheric absorption bands. Fluorescence maps show a large spatial variability between different vegetation types, which are not detected with classical remote sensing approaches.It could be shown that different crop types largely differ in emitting fluorescence that is related to the activity of the photosynthetic machinery and allows separating annual and perennial C3 and C4 crops and grasses. Additionally, it could be shown in different case studies that the two peak feature of sun-induced fluorescence emission is related to (i) the total absorbed radiation by photosynthetically active chlorophyll (far-RED peak) and (ii) the functional status of photosynthesis and vegetation stress (RED peak). Thus, the dynamic changes of the two peaks of fluorescence code for structural and functional variability within canopies. Sun-induced fluorescence thus can be used to better understand and to monitor the dynamic adaptations of the photosynthetic machinery of plants to the ever changing environmental conditions. Sun-induced fluorescence thus constitutes a novel and highly relevant remote sensing signal to understand and manage our natural and managed ecosystems in times of global change and to facilitate a sustainable use of plants and plant resources
Plasma-surface interactions in fusion devices represent a critical issue for the design and opera... more Plasma-surface interactions in fusion devices represent a critical issue for the design and operation of diagnostic systems based on transmission of light signals from plasma where metallic mirrors will be used as first plasma-viewing elements. In this work, the behavior of metallic mirrors is investigated with respect to the influence of plasma-induced changes of surface morphology and composition on the surface reflectivity. The work is based on the series of dedicated experiments performed in tokamaks TEXTOR and DIII-D, in which pre-characterized metallic mirrors were exposed during the plasma operation (TEXTOR) and during the thermo-oxidative wall conditioning (DIII-D). The morphology, composition and optical properties of the mirror surfaces are analyzed post-mortem. To understand the observed surface modifications, ion-surface interactions are modelled with the SDTrimSP code. The processes responsible for modifications of the surface morphology and composition under energetic ...
The ability to investigate the Earth’s environment will be greatly improved by hyperspectral sate... more The ability to investigate the Earth’s environment will be greatly improved by hyperspectral satellite data. The FLuorescence EXplorer (FLEX) will be the first hyperspectral mission designed to monitor the photosynthetic activity of the terrestrial vegetation layer by using a completely novel technique measuring the sun-induced chlorophyll fluorescence (SIF) signal that originates from the core of the photosynthetic machinery. In preparation of the upcoming FLEX satellite mission that will be launched in 2022 a large field campaign, namely FLEXSense, was conducted in summer 2018 including representative study sites at several locations in middle and south Europe as well as North America.During the different/various field activities, airborne data was acquired with the hyperspectral airborne imager HyPlant, whichthat consists of two sensor heads. The DUAL module is a line-imaging push-broom sensor, which providinges contiguous spectral information from 370 to 2500 nm. The vegetationc...
When plants absorb light, not all energy is converted by photosynthesis, but excess energy is rel... more When plants absorb light, not all energy is converted by photosynthesis, but excess energy is released as heat or emitted as sun-induced chlorophyll fluorescence (F). This signal, related to the photosynthetic efficiency of plants, has been intensively studied and measured from ground, airborne and satellite. However, retrieving sun-induced fluorescence (F) from remote sensing data is challenging because accurate modeling of atmospheric influences is required.. The advent of the airborne imaging spectrometer HyPlant made possible to produce F maps in high-spatial resolution (1-3 meters), which is a valuable tool to better understand F at relevant ecosystem scale. Currently, two different algorithms are used routinely to retrieve red and far-red F from HyPlant. Both methods are based on the O 2 absorption bands, but while iFLD method employs a semi-empirical atmospheric correction (i.e., bare-soils), the SFM makes use of a physically-based atmospheric modeling (MODTRAN5 code). A comm...
Regional mapping of Fluorescence in a heterogeneous agriculture landscapeMaria Matveeva1, Patrick... more Regional mapping of Fluorescence in a heterogeneous agriculture landscapeMaria Matveeva1, Patrick Rademske1, Alexander Damm2, Cosimo Brogi3, Wolfgang Korres4, and Uwe Rascher11 Institute of Bio- and Geosciences, IBG-2: Plant Sciences, Forschungszentrum Jülich GmbH, Leo-Brandt-Str., 52425 Jülich, Germany2 Remote Sensing Laboratories, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland3 Institute of Bio- and Geosciences, IBG-3: Agrosphere, Forschungszentrum Jülich GmbH, Leo-Brandt-Str., 52425 Jülich, Germany4 Institute of Geography, University of Cologne, Albertus-Magnus-Platz , D-50923 Cologne, GermanyThe increased interest of the scientific community to the remote sensing of sun-induced chlorophyll fluorescence (F) leads to a large number of fruitful and interesting experiments on the field scale. On the other side, satellite data became available, from which fluorescence on the global scale can be derived. However, it is still an open question, how representativ...
Due to their high-quality routine measurement programme, ICOS sites lend themselves as anchors fo... more Due to their high-quality routine measurement programme, ICOS sites lend themselves as anchors for additional experiments. As an example, we describe the CloudRoots campaign near the agricultural site Selhausen (DE-RuS) in spring 2018.Little is known about the two-way feedback between stomatal control (controlling the partitioning of energy into sensible and latent heat) and cloud development (affecting potential evapotranspiration). Coupled models of the soil-vegetation-boundary layer continuum have the potential to explain this, but their calculations are only as robust as the data used to parameterize or validate the model. For observations and modelling, the challenge is in interconnecting processes at leaf level to the physics of turbulence and clouds.We temporarily amend the existing radiation, flux and soil dynamics/respiration measurements of the ICOS site by scintillometry, sap-flow and leaf-level flux measurements, vertical profiles and isotope measurements. Scintillometer...
Non-invasive geophysical fixed-boom multi-coil electromagnetic induction (EMI) instruments return... more Non-invasive geophysical fixed-boom multi-coil electromagnetic induction (EMI) instruments return apparent electrical conductivity (ECa) values that depend on subsurface soil properties. Using different transmitter-receiver coil separations and orientations, ECa values of different depths of investigation (DOI) are obtained. After calibration, the quantitative EMI data are inverted to obtain electrical conductivity (σ) changes over depth assuming a layered subsurface model. Airborne hyperspectral measurements are used to estimate plant performance and growth, however, the top- and subsoil structural changes influencing plant performance and growth is often ignored. Here, we have investigated the origin of observed patterns in sun-induced fluorescence data by performing quantitative large-scale EMI measurements and quantitative inversions. The fixed-boom multi-coil EMI ECa data of nine coil configurations indicated spatial patterns due to buried paleo-river channels. After inversion,...
Photosynthesis dynamically adapts to changing environmental conditions. Extreme environmental con... more Photosynthesis dynamically adapts to changing environmental conditions. Extreme environmental conditions such as high temperature and water limitation directly reflect in the photosynthetic performance as vegetation stress. To monitor photosynthesis dynamics at large vegetation scales, indicators of stresses in vegetation extracted by non-invasive techniques can be used.Spectral reflectance indices such as NDVI and PRI have been tested to provide rapid and non-invasive estimation of photosynthesis at regional scales. Unfortunately, these indices lack sensitivity to short-term vegetation physiological changes. Alternatively, a passive retrieval of sun-induced chlorophyll fluorescence (SIF) using high performance imaging spectroscopy has been suggested. SIF emission is closely related to the status of photosynthesis and therefore has the potential to track adaptation of this process to changes in environmental conditions and plant status. Although SIF emission represents a weak signal in comparison to the reflected radiation, recent research provides evidence that SIF can be measured by exploiting solar and atmospheric absorption lines using high performance spectrometers.In this contribution, we present the design and first results of an experiment that aimed to evaluate the capability of the new remote observable SIF and common reflectance based indices to detect plant stress. In the experiment, carried out in June and July 2014 in Latisana (Italy), we treated homogeneous lawn plots to provoke different level of stress in plants. In particular, we applied the herbicide (Dicuran) in different concentrations to four plots, three other plots were treated with the anti-transpirant Vaporgard; while three remaining plots were not treated and used as control. Diurnal variations in SIF and surface reflectance were evaluated for period of two weeks, using the high performance imaging spectrometer HyPlant. HyPlant is a dedicated fluorescence spectrometer and allows measuring radiance in the wavelength range between 400 nm and 2500 nm with a high spectral resolution of 0.26 nm between 670 nm and 780 nm. Data was recorded for spatial resolution of 1 meter per pixel.Airborne data was calibrated and validated using high resolution top of canopy measurements of reflectance and SIF. Vegetation indices and SIF were calculated for treated and non-treated areas and compared with corresponding ground measurements. Additional measurements of CO2 and H2O fluxes using chambers and an eddy covariance tower to monitor photosynthetic activity were performed.First results show contrasting responses of emitted SIF and vegetation indices for plant stress: SIF strongly increased after the treatment with Dicuran followed by a slow decrease down to the initial values. The Meris Terrestrial Chlorophyll Index (MTCI) showed a clear decrease after the herbicide treatment. We conclude that SIF is a promising new observable sensitive to plant stress which provides complementary information to commonly used remote observables origin form reflectance spectroscopy. We suggest a combined use of SIF and reflectance spectroscopy to establish reliable approaches for rapid, early, and non-invasive plant stress detection
Photosynthesis is the most important exchange process of CO2 between the atmosphere and the land-... more Photosynthesis is the most important exchange process of CO2 between the atmosphere and the land-surface. Spatial and temporal patterns of photosynthesis depend on dynamic plant-specific adaptation strategies to highly variable environmental conditions e.g. light, water, and nutrient availability. Therefore, an accurate quantification of photosynthetic CO2 uptake, commonly referred to as gross primary productivity (GPP), is a key parameter to monitor plant performance.Hyperspectral reflectance techniques often failed to quantify actual photosynthetic light use efficiency (LUE) and only allow measuring pigment content and canopy structure. One promising approach for obtaining global estimates of plant photosynthesis is the use of Sun Induced Chlorophyll Fluorescence (SIF). SIF has been proposed as a direct indicator of plant photosynthesis, and several studies have demonstrated its relationship with vegetation functioning at leaf and canopy level.In this presentation we summarize the...
This data set contains ground-based apparent electrical conductivity (ECa) of eight depth ranges ... more This data set contains ground-based apparent electrical conductivity (ECa) of eight depth ranges of investigation. These were inverted for a three-layer electrical conductivity model. Five .dat files contain the depth-specific inverted electrical conductivity and respective layer thicknesses. Three dat-files correspond to airborne plant performance data. Additionally, six figures show the linear regressions between soil information (electrical conductivity property) and plant performance and one video shows the quasi-3D EMI inversion results.
IGARSS 2020 - 2020 IEEE International Geoscience and Remote Sensing Symposium, 2020
In summer 2019 the SARSense campaign was held in Jülich, Germany, to provide insights into the po... more In summer 2019 the SARSense campaign was held in Jülich, Germany, to provide insights into the potentials and specifications of the ESA Copernicus candidate mission ROSE-L (Radar Observation System for Europe). ROSE-L will consist of two satellites that carry a polarimetric L-band SAR. Since the L-band signal can penetrate through many natural materials such as vegetation, dry snow and ice, the mission will provide additional information that cannot be gathered by the Copernicus Sentinel-1 C-band SAR mission. The overall objective of the SARSense 2019 campaign is to analyze the mission design concerning its potential for agricultural monitoring services including target applications such as soil moisture monitoring, irrigation management, crop type discrimination, food security and precision farming. The SARSense in situ measurements of soil moisture, soil temperature, vegetation properties, UAS-based multispectral and thermal mapping, as well as the airborne SAR observations are pr...
The SARSense campaign in the Jülich area (Germany) in summer 2019 was performed to support the ES... more The SARSense campaign in the Jülich area (Germany) in summer 2019 was performed to support the ESA Copernicus high priority mission ROSE-L. Airborne SAR signals in C-and L-band, drone imagery, in situ soil and plant parameters, as well as biophysical variables in the lab were measured to provide a comprehensive data set to study details of the mission design for agricultural applications. Although an in depth analysis will be performed soon, the preliminary outcome of the dry summer example campaign is as follows: An L-band SAR monitoring in the Copernicus program will provide an added value to the existing C-band capacities of Sentinel-1 (A/B). Simultaneous C-and L-band observations may help to disentangle the different processes in the plant and the soil. Single frequency observations may tend to be misinterpreted.
Vilà-Guerau de Arellano et al.: CloudRoots depend on the scale where the measurement were taken a... more Vilà-Guerau de Arellano et al.: CloudRoots depend on the scale where the measurement were taken and on the plant growing stage.
The HyPlant imaging spectrometer is a high-performance airborne instrument consisting of two sens... more The HyPlant imaging spectrometer is a high-performance airborne instrument consisting of two sensor modules. The DUAL module records hyperspectral data in the spectral range from 400–2500 nm, which is useful to derive biochemical and structural plant properties. In parallel, the FLUO module acquires data in the red and near infrared range (670–780 nm), with a distinctly higher spectral sampling interval and finer spectral resolution. The technical specifications of HyPlant FLUO allow for the retrieval of sun-induced chlorophyll fluorescence (SIF), a small signal emitted by plants, which is directly linked to their photosynthetic efficiency. The combined use of both HyPlant modules opens up new opportunities in plant science. The processing of HyPlant image data, however, is a rather complex procedure, and, especially for the FLUO module, a precise characterization and calibration of the sensor is of utmost importance. The presented study gives an overview of this unique high-perform...
Soil structures at depth obtained by quantitative 3D electromagnetic induction data inversions ... more Soil structures at depth obtained by quantitative 3D electromagnetic induction data inversions not by apparent electrical conductivity maps Deeper subsoil characteristics correlate with airborne sun-induced fluorescence data indicating soil moisture effects on plant performance Quantitative inverted electrical conductivity model together with plant data help to inform and improve soil-vegetation-atmosphere models
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Papers by Maria Matveeva