Application of Remote Sensing and GIS Methods for the Automatic Extraction of Single Trees Based on Digital Aerial Images and Elevation Models

The paper gives a short overview about the existing data base and extraction methods for single tree detection. Forest remote sensing has a long tradition and a variety of methods for single tree extraction have already been developed. Most studies and methods focus either on the analysis of satellite images or airborne laser data and on the extraction of coniferous trees. The automatic detection of deciduous trees is still a great challenge. This paper describes different methods of single tree extraction with focus on the automatic extraction of deciduous trees from aerial imagery. Single trees can be extracted by using aerial true-ortho images and photogrammetrically produced digital surface models as input data and a combination of remote sensing methods and GIS analyses with completeness and correctness over 80 percent. The presented method enables the extraction of tree tops as well as tree-crowns for deciduous trees. For the automatically extracted singles trees important attributes like exact position or average crown diameter are calculated and added to the tree objects. The extracted trees can be used for the modeling of trees in virtual environments or for forest area inventories

Oral hygiene knowledge versus behavior in children: A questionnaire-based, interview-style analysis and on-site assessment of toothbrushing practices

Objectives: Oral hygiene plays an important role in eliminating biofilms and preventing dental caries. However, the implementation of oral health knowledge that children learn from their parents and through school dental health programmes remains poorly studied. This study aimed to investigate oral hygiene knowledge and its practical utilization in children and young adolescents (CYAs) aged 2–15 years. Material and methods: This was a questionnaire‐based, interview‐style community survey and on‐site practical assessment of CYAs' toothbrushing skills conducted during two 1‐day public science‐promoting events held at a major German university hospital in consecutive years. CYAs first answered questions on toothbrushing frequency, dental aids used, and dental care. They subsequently underwent diagnostic staining and demonstrated their brushing technique and method. CYAs' responses (percentages) to questionnaire items addressing oral hygiene knowledge and practice, and on‐site assessment of toothbrushing skills served as the main outcome measures. Results: Of 244 participating CYAs, 178 (73%) CYAs had no caries experience, the percentage increasing with age from 5% in 2–5‐year‐olds to 40% in those aged > 10 years. Of 117/244 (48%) indicating that teeth should be brushed three times daily, 80/ 117 (68%) self‐reported twice‐daily brushing, 32/117 (27%) reported brushing three times, and 4/117 (3%) stated doing so only once. Although 131/244 (54%) considered that teeth should be brushed for 3 min, 77/131 (59%) self‐reported actually doing so and 41/131 (31%) reported brushing for 2min. Seventeen of 42 (40%) participants aged > 10 years showed no systematic brushing method, with 21/42 (50%) failing to clean their teeth completely. Participants aged 6–10 years exhibited the highest proportion (97/134, 72%) of complete cleaning. One hundred and forty‐six of 244 (60%) of CYAs knew about floss; 63/134 (43%) reported using it. Good adherence to oral health recommendations (i.e., brushing ≥ 2/day for ≥2min) was observed in 212/ 244 (87%) CYAs, the remaining 32/244 (13%) exhibiting poor adherence. Conclusion: CYAs knew about the importance of oral hygiene and cleaned their teeth frequently. However, translation of their knowledge into practice showed deficiencies. Repeated encouragement to put oral health knowledge into practice is important

Case study: Near real-time thermal mapping to support firefighting and crisis management

Hot and dry summers have led to an increase in forest fires both concerning num-bers and intensity in north-eastern Germany in the last years. In the project FireSense the German Aerospace Center (DLR) has adapted its sensor system MACS (Modular Airborne Camera System) with a set of thermal mid- and long wave infrared (MWIR and LWIR) cam-eras to detect, monitor and quantify high temperature events (HTE) like forest fires. Ground-based, airborne and spaceborne measurements over fire-experiments are synchronized for cross-validation of the systems and to test the developed workflows. In summer 2019 gas flaring tests were conducted in cooperation of DLR and the Federal In-stitute for Material Research and Testing (BAM), parallel several large forest fires in Bran-denburg (Lieberose) and Mecklenburg-Vorpommern (Lübtheen) developed. In coordination with the crisis management group (local authorities, firefighters, armed forces, federal po-lice) to get the permits MACS conducted 3 flights over the fires in altitudes between 6000 (sunny) down to 3500 ft (under clouds), Lübtheen was covered twice, on July 2 and July 4, when the fire was already under control. Synchronously firefighting helicopters operated close to ground, also delivering videos of the fires for visual interpretation. To get both background temperatures for orientation and landscape features and also infor-mation about the fires within one data set, a broad calibration range for the LWIR camera was commanded. Using synchronized position- and orientation data of MACS with given calibration data and a Digital Terrain Model, direct geocoding and the processing of near real-time mosaics was possible using the DLR workflow even without post-processing. The accuracy was sufficient for planning purposes. Geo-tiff maps were delivered shortly after landing within less than three hours. The real-time capabilities of the system could not be used as the flights were conducted on very short notice and the radio link was not installed. The thermal data were delivered as false color heat maps. They show the thermal anomalies very well, clearly discriminating burning area, recently burnt area and unaffected forest. In the RGB data the ground fires are rarely visible as they are covered by and almost did not affect the closely standing crowns. The spread of the fires can be seen in the overlapping re-gions of adjacent flight lines. Data exchange and use of the data proved to be difficult due to limited data rates and IT in-frastructure in the command and situation center in the field, sometimes taking more time than the acquisition and processing. This reduces the practical benefit for the data in the field. For future planned experiments for real-time mapping of forest fires this will be one of the main points to improve the latency of the data transfer to the control center ideally by us-ing a live data link and to optimize the coordination with the control center. Further activi-ties will be coordinated by the Helmholtz Innovation Lab OPTSAL (Optische Technologien für Situationserfassung im Sicherheitsbereich), which was started at DLR in 2020. In OPTSAL hard- and software solutions are developed and activities concerning situational awareness for safety and security are coordinated with industry and authorities

Effect of Early High-Dose Recombinant Human Erythropoietin on Behavior and Quality of Life in Children Aged 5 Years Born Very Preterm: Secondary Analysis of a Randomized Clinical Trial

IMPORTANCE In light of the promising neuroprotective properties of recombinant human erythropoietin (RHEpo), the Swiss EPO Neuroprotection Trial was started to investigate its effect on neurodevelopment in very preterm infants. The results of the primary and secondary outcome analysis did not show any effect of RHEpo on cognitive performance, neuromotor outcomes, or somatic growth of the study participants at ages 2 or 5 years. OBJECTIVE To investigate whether early high-dose RHEpo improves behavioral outcomes and health-related quality of life (HRQoL) at age 5 years. DESIGN, SETTING, AND PARTICIPANTS This was a prespecified secondary analysis of the double-blind, placebo-controlled, multicenter Swiss EPO Neuroprotection randomized clinical trial, which was conducted at 5 level-III perinatal centers in Switzerland. Infants born between 26 weeks 0 days' and 31 weeks 6 days' gestation were recruited between 2005 and 2012 and followed-up until age 5 years (last follow-up in 2018). Data were analyzed from January 6 to December 31, 2021. INTERVENTIONS Infants were assigned to receive either RHEpo (3000 IU/kg) or placebo (saline, 0.9%) intravenously 3 times within the first 42 hours after birth. MAIN OUTCOMES AND MEASURES The prespecified parent-reported measures of behavioral outcomes and health-related quality of life (HRQoL) of their children at the age of 5 years were assessed by two standardized questionnaires: the Strengths and Difficulties Questionnaire (behavioral outcomes) and the KIDSCREEN-27 (HRQoL). RESULTS Among 448 randomized infants, 228 infants were assigned to the RHEpo group and 220 infants were assigned to the placebo group. Questionnaire data were available for 317 children (71%) at a mean (SD) age of 5.8 (0.4) years (mean [SD] gestational age at birth, 29.3 [1.6] weeks; mean [SD] birth weight 1220 [340] grams; 128 [40%] female infants). At the age 5 years follow-up, the mean (SD) total difficulties score in the RHEpo group (8.41 [5.60] points) was similar to that of the placebo group (7.76 [4.81]) (P = .37). There were no statistically significant differences between the groups in any other outcome measures. CONCLUSIONS AND RELEVANCE This secondary analysis of a randomized clinical trial showed no evidence for an effect of early high-dose RHEpo administration on behavioral outcomes or HRQoL in children born very preterm at early school age. TRIAL REGISTRATION - ClinicalTrials.gov Identifier: NCT00413946

Super-high-resolution Earth observation datasets of North American permafrost landscapes

While temperatures are increasing on the global scale, the Arctic regions are especially vulnerable to this changing climate and landscapes underlain by permafrost experience increased thaw and degradation. The enhanced warming of organic-rich frozen ground can have severe consequences on infrastructure and ecosystems and is projected to become a highly relevant driver of greenhouse gas fluxes into the atmosphere. Degrading permafrost landscapes occur extensively in vast areas of the North American Arctic, directly affecting communities and ecosystems. To identify and quantify these widespread degradation phenomena over vast areas, we require highest-resolution Earth observation dataset that we collect during aerial imaging campaigns. We here report on observations and first results from three airborne campaigns in 2018, 2019 and 2021. We performed large-scale monitoring of permafrost-affected areas in northern Canada and Alaska, focusing on sites that experienced disturbances in the past or recently. This included sites with vulnerable settlements, coastal erosion, thaw slumping, lake expansion and drainage, ice-wedge degradation and thaw subsidence, fire scars, pingos, methane seeps, and sites affected by beaver activities. All surveys were flown with the Alfred Wegener Institute's Polar-5 and -6 scientific airplanes at 500-1500 m altitude above terrain. The onboard sensor, the Modular Aerial Camera System (MACS), a very-high-resolution multispectral camera developed by the German Aerospace Center, operated in the visible (RGB) and near-infrared (NIR) domain. From the comprehensive collection of multiple TB of gathered data, super-high-resolution (up to 7 cm/px) RGB+NIR image mosaics and stereophotogrammetric digital surface models were derived. By presenting the data and first analyses, we would like to invite the community to discuss best use for maximized benefit of the data, in order to substantially contribute to our understanding of permafrost thaw dynamics

Real-time Distribution of an Airborne Situational Picture into Command and Control Systems

The Modular Aerial Camera System (MACS) has been developed, built and operated for more than a decade at the Institute of Optical Sensor Systems, German Aerospace Center (DLR, Berlin). It is a highly flexible system which is adapted to a wide range of carrier systems like Unmanned Aerial Systems (UAS), helicopters or piloted aircrafts. It is used for a variety of applications like mapping of environmental changes, 3D-reconstruction and urban mapping. One of the main goals of the system is to provide fast and reliable georeferenced information and situational awareness for civil security applications. In this paper we present the most recent developments of MACS, enabling the integration of georeferenced image mosaics in real-time into command and control (C2) systems, GIS-software and mobile devices for first responders. The use of satellite communication systems allows the worldwide use of MACS even in destroyed environments without telecommunication services. The georeferenced image mosaics are disseminated to end users worldwide via web- map services. The developments are illustrated along several use cases including forest-fire and flooding. The transfer of selected scientific developments and technologies to operational use and integration into C2 systems is done with commercial partners as part of the Helmholtz Innovation Lab OPTSAL. The workflow has successfully been certified to be integrated into a Web Map Service standard protocol, so the MACS-data can be shared in GIS systems worldwide. For disaster relief situations we demonstrated a workflow for integration and distribution of our live-map to all teams via the United Nations (UN) International Search And Rescue Advisory Group (INSARAG) coordination management system. Further developments include the use of onboard-classification to extract relevant information and reduce the amount of data to be transferred

Airborne LiDAR and stereo-photogrammetric characterization of permafrost landscapes and thaw subsidence

Rapid climate change in the northern high latitudes has a strong impact on permafrost stability, apparent as coastal erosion, subsidence, or lake dynamics with potentially severe consequences for local communities and ecology. In a rapidly warming Arctic, the monitoring of these processes is essential to understand and predict permafrost dynamics over the upcoming decades. These landscape dynamics are highly diverse, localized, but widely distributed and require datasets with very high spatial resolution, which are barely achieved by satellite data alone. Repeat observations over several years allow for unprecedented insights into highly critical landscape dynamics and the potential integration with and validation of more coarse resolution satellite data. AWI’s research aircraft (Polar-5 and Polar-6) were equipped with airborne LiDAR (full-waveform, multi-echo) as well with experimental modular sensors such as the DLR-developed multi-spectral optical Modular Airborne Camera System (MACS) with a spatial resolution of few cm, stereo capabilities and a very broad radiometric range. The incoming data stream of acquired laser return point cloud data as well as hundreds of thousands of high-resolution images for individual campaigns poses new challenges of handling and processing large data volumes. Here we present an overview about past and upcoming flight campaigns in Alaska and northwestern Canada. Furthermore, we will show applications of the acquired datasets, such as assessments of subsidence, coastal erosion or infrastructure development

Lost in diversity: the interactions between soil-borne fungi, biodiversity and plant productivity

There is consensus that plant species richness enhances plant productivity within natural grasslands, but the underlying drivers remain debated. Recently, differential accumulation of soil-borne fungal pathogens across the plant diversity gradient has been proposed as a cause of this pattern. However, the below-ground environment has generally been treated as a ‘black box’ in biodiversity experiments, leaving these fungi unidentified. * Using next generation sequencing and pathogenicity assays, we analysed the community composition of root-associated fungi from a biodiversity experiment to examine if evidence exists for host specificity and negative density dependence in the interplay between soil-borne fungi, plant diversity and productivity. * Plant species were colonised by distinct (pathogenic) fungal communities and isolated fungal species showed negative, species-specific effects on plant growth. Moreover, 57% of the pathogenic fungal operational taxonomic units (OTUs) recorded in plant monocultures were not detected in eight plant species plots, suggesting a loss of pathogenic OTUs with plant diversity. * Our work provides strong evidence for host specificity and negative density-dependent effects of root-associated fungi on plant species in grasslands. Our work substantiates the hypothesis that fungal root pathogens are an important driver of biodiversity-ecosystem functioning relationships

Evaluation of Digital Surface Models by Semi-Global Matching

This paper considers a processing chain for automatically creating high resolution digital surface models and true ortho-images from aerial and satellite image data. It has been developed at the Institute of Robotics and Mechatronics of the German Aerospace Center (DLR-RM). The processing chain is based on Semi-Global Matching (SGM) that uses a radiometric robust matching cost and an optimization that is based on a global smoothness constraint. SGM is especially suitable for creating models of urban scenes, where sharp depth discontinuities and small details need to be precisely reconstructed. However, the technique also produces very good results in scenes with forest and mountains. In this paper we give an overview of the processing chain and evaluate its results on test data sets from different aerial cameras. It is concluded that SGM permits the creation of high quality surface models that are more accurate and provide much more detail than a surface model from an aerial laser scanner. We also discuss the conditions under which good surface models can be produced by SGM. For very good results, an overlap of 80 % or more along track and 70 % across track should be provided