Stefanie Holzwarth

Stefanie Holzwarth
German Aerospace Center (DLR) | DLR · Department: Land Surface

About

114
Publications
19,697
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
515
Citations
Citations since 2016
65 Research Items
397 Citations
2016201720182019202020212022020406080100120140
2016201720182019202020212022020406080100120140
2016201720182019202020212022020406080100120140
2016201720182019202020212022020406080100120140

Publications

Publications (114)
Conference Paper
Operational Calibration and Validation (Cal/Val) is required to ensure the quality of and build confidence in Copernicus data. However, current Cal/Val activities are limited and insufficiently harmonized between different missions. The objective of the Copernicus H2020 Cal/Val Solution (CCVS) project is to define a holistic solution for all Copern...
Conference Paper
The Environmental Mapping and Analysis Program (EnMAP) hyperspectral satellite mission was successfully launched on 1st April 2022. The mission aims to monitor and characterise Earth’s environment in the spectral range from 420 - 2450 nm. The VNIR sensor provides 91 science channels ranging from 420 - 1000 nm with an average Spectral Sampling Dista...
Conference Paper
Full-text available
In this study a statistical orbit drift correction method was applied to TIMELINE AVHRR LST from NOAA 7, 9, 11, 14, 16, 18 and 19 afternoon overpasses at 12 sites across Europe. The corrected LST anomalies were validated against Ta anomalies from nearby meteorological stations. The results showed an improvement of the correlation (R) between the LS...
Conference Paper
Full-text available
In the TIMELINE project, consistent SST product were developed from AVHRR brightness temperatures over Europe and North Africa for the period 1982-2018. The daily, 10-daily and monthly Level 3 products contain statistics of SST (minimum, maximum, median, mean) for the respective period. Only high quality SST is used, which is ensured by filtering a...
Conference Paper
The AVHRR (Advanced Very High Resolution Radiometer) mission offers a data set that goes back continuously to the early 1980s. These data are processed and examined as part of the TIMELINE (TIme series processing of Medium resolution Earth observation data assessing Long-term dynamics In our Natural Environment) project, which focuses on a 30-year...
Conference Paper
Full-text available
LST is recognized as one of the Essential Climate Variables by the World Meteorological Organization. It is a key parameter for climate models and a direct indicator of global warming. The Advanced Very High-Resolution Radiometer (AVHRR) is the only sensor that has been providing spatially and temporally continuous daily measurements for 40 years....
Article
Full-text available
Central Europe was hit by several unusually strong periods of drought and heat between 2018 and 2020. These droughts affected forest ecosystems. Cascading effects with bark beetle infestations in spruce stands were fatal to vast forest areas in Germany. We present the first assessment of canopy cover loss in Germany for the period of January 2018–A...
Conference Paper
Full-text available
The Urban Heat Island (UHI) effect is one of the most prominent signs of human impact on the Earth system. This phenomenon has significantly altered the energy exchange between land surfaces and the atmosphere which has led to several negative impacts on the quality of city life in terms of air and water quality, energy consumption, vegetation grow...
Conference Paper
Vast areas of Central and Northern Europe experienced a pronounced drought in 2018. Germany, among other countries, was heavily affected. In some parts of the country, exceptionally dry conditions continued into spring 2021. The effects of the 2018 drought had a strong impact on Central European forests, particularly in the Czech Republic and Germa...
Article
Full-text available
Today, the ground segments of the Landsat and Sentinel missions provide a wealth of well-calibrated, characterized datasets which are already orthorectified and corrected for atmospheric effects. Initiatives such as the CEOS Analysis Ready Data (ARD) propose and ensure guidelines and requirements so that such datasets can readily be used, and inter...
Article
Full-text available
Earth Observation satellite data allows for the monitoring of the surface of our planet at predefined intervals covering large areas. However, there is only one medium resolution sensor family in orbit that enables an observation time span of 40 and more years at a daily repeat interval. This is the AVHRR sensor family. If we want to investigate th...
Article
Full-text available
Land Surface Temperature (LST) is an important parameter for tracing the impact of changing climatic conditions on our environment. Describing the interface between long- and shortwave radiation fluxes, as well as between turbulent heat fluxes and the ground heat flux, LST plays a crucial role in the global heat balance. Satellite-derived LST is an...
Conference Paper
The DLR Earth Sensing Imaging Spectrometer (DESIS) is a space-based instrument installed and operated on the International Space Station (ISS). This space mission is the achievement of the collaboration between the German Aerospace Center (DLR) and the US company Teledyne Brown Engineering (TBE). DLR has developed the instrument and the software fo...
Article
Full-text available
Effects of climate change-induced events on forest ecosystem dynamics of composition, function and structure call for increased long-term, interdisciplinary and integrated research on biodiversity indicators, in particular within strictly protected areas with extensive non-intervention zones. The long-established concept of forest supersites genera...
Article
Monitoring global biodiversity from space through remotely sensing geospatial patterns has high potential to add to our knowledge acquired by field observation. Although a framework of essential biodiversity variables (EBVs) is emerging for monitoring biodiversity, its poor alignment with remote sensing products hinders interpolation between field...
Conference Paper
The DLR Earth Observation Center (EOC) in Oberpfaffenhofen has been an active contributor to the hyperspectral remote sensing community for more than 25 years. Since 2007 it operates the ISO-certified Optical Airborne Remote Sensing (OpAiRS) user service which aims to provide highly accurate airborne hyperspectral data to DLR scientists and their c...
Presentation
In this presentation, we report on the preliminary findings of the H2020 project “Copernicus Cal/Val Solution” (CCVS), whose objective is to define a holistic solution to the cal/val of the Copernicus Sentinel missions. We focus more specifically on synergies of the Sentinel-2 mission with other Sentinel or third-party missions, in terms of cal/val...
Conference Paper
In this presentation, we report on the preliminary findings of the H2020 project “Copernicus Cal/Val Solution” (CCVS), whose objective is to define a holistic solution to the cal/val of the Copernicus Sentinel missions. We focus more specifically on synergies of the Sentinel-2 mission with other Sentinel or third-party missions, in terms of cal/val...
Article
Full-text available
Mapping a specific tree species at individual tree level across landscapes using remote sensing is challenging, especially in forests where co-occurring tree species exhibit similar characteristics. In Central European mixed forests, silver fir and Norway spruce have been identified as a pair of coniferous tree species with similar spectral and str...
Article
Full-text available
Machine learning algorithms, in particular, kernel-based machine learning methods such as Gaussian processes regression (GPR) have shown to be promising alternatives to traditional empirical methods for retrieving vegetation parameters from remotely sensed data. However, the performance of GPR in predicting forest biophysical parameters has hardly...
Article
Full-text available
Forests in Germany cover around 11.4 million hectares and, thus, a share of 32% of Germany’s surface area. Therefore, forests shape the character of the country’s cultural landscape. Germany’s forests fulfil a variety of functions for nature and society, and also play an important role in the context of climate levelling. Climate change, manifested...
Article
Full-text available
This article presents and analyses the modular architecture and capabilities of CODE-DE (Copernicus Data and Exploitation Platform – Deutschland, www.code-de.org), the integrated German operational environment for accessing and processing Copernicus data and products, as well as the methodology to establish and operate the system. Since March 2017,...
Conference Paper
Since its creation in 2000, the European Facility for Airborne Research, EUFAR, evolved into the central network for the airborne research community in Europe. From the beginning until 2018, EUFAR has received funding within the different Framework Programmes of the European Commission. In January 2018, EUFAR became an AISBL (international non-prof...
Conference Paper
The Bohemian Forest right at the national border between the Czech Republic, Austria and Bavaria in Germany is a unique area of forested mountains and plateaux with relatively harsh climates and many peat bogs. Historically, the human impact in the region was comparability low and therefore led to the preservation of a unique forest ecosystem. The...
Conference Paper
The amount of Earth Observation (EO) data is increasing at an unprecedented rate. The European Copernicus program, in particular with Sentinel-1 and Sentinel-2 imagery in 10 m spatial resolution, is a major data contributor. These large volumes of data require not only sophisticated data storage and access options, but also new big spatial data ana...
Conference Paper
Full-text available
We present architecture and various capabilities of CODE-DE (Copernicus Data and Exploitation Platform - Deutschland, www.code-de.org) which is the German operational environment for accessing and processing Copernicus Sentinel products, a so-called Copernicus collaborative ground segment activity. Since March 2017 the element for online data acces...
Conference Paper
Full-text available
In order to produce accurate and meaningful results from airborne hyperspectral data analysis, it is essential to have exact knowledge about the quality of the image data itself. Small differences in reflectance already produce diverse results particularly when it comes to vegetation analysis. Especially within the complex environment of forested a...
Conference Paper
Copernicus establishes an operational European Earth Observation capacity. Data from multiple sources - first and foremost the Sentinel satellite systems - feed services and provide users with reliable and up-to-date information regarding environmental and security issues. The main Sentinel Internet based data access infrastructure is implemented b...
Conference Paper
The European Facility for Airborne Research, EUFAR, is an Integrating Activity of the 7th Framework Programme (FP7) of the European Commission with funding covering the period 2014-2018. The current EUFAR follows three previous contracts under FP5, FP6 and FP7, and currently represents a 24-partner consortium of institutions and organisations invol...
Conference Paper
The Bavarian Forest National Park is a unique area of forest stands that developed with low anthropogenic interference into a landscape with remnants of a primeval forest. There is a high interest of the National Park authority to investigate the composition and development of the forest ecosystem. However conventional forest inventories are time-c...
Article
Quantification of vegetation properties plays an important role in the assessment of ecosystem functions with leaf dry mater content (LDMC) and specific leaf area (SLA) being two key functional traits. For the first time, these two leaf traits have been estimated from the airborne images (HySpex) using the INFORM radiative transfer model and Contin...
Conference Paper
Calibration and validation are fundamental for obtaining quantitative information from Earth Observation (EO) sensor data. Recognising this and the impending launch of at least five sensors in the next five years, the International Spaceborne Imaging Spectroscopy Technical Committee instigated a calibration and validation initiative. A workshop was...
Poster
Full-text available
Marshes are highly dynamic ecosystems based on the interaction between sea level, land elevation, vegetation cover and sediment accretion. In the current study case, the acid mine drainage-contaminated River Odiel water in the estuary, interact with marine salt water resulting in complex geochemical processes developing salt crusts in intratidal pl...
Article
Full-text available
The Bavarian Forest National Park, established in 1970, is a unique area of forests with large non-intervention zones, which promote a large-scale rewilding process with low human interference. Thus, the National Park authority is particularly interested in investigating the structure and dynamics of the forest ecosystems within the park. However,...
Conference Paper
Forest ecosystems respond very sensitively to climate and atmospheric changes. Feedback mechanisms can be measured via changes in albedo, energy balance and carbon storage. The Bavarian Forest National Park is a unique forest ecosystem with large non-intervention zones, which promote a large scale re-wilding process with low human interference. It...