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Authors: Aicardi. I.; Advisor: -; Participants: - (2016) - In the last years we have witnessed a rapid development of UAVs (Unmanned Aerial Vehicles), especially for image collection. One of the advantages is the possibility to perform high resolution and repeated flights in a cheap way to detect changes over time. Thus, dynamic scenes can be monitored acquiring image blocks in different epochs in a flexible way. Anyway, most of UAVs are not able to provide accurate direct geo-referencing information, so image blocks from different epochs still need to be co-registered to efficiently detect changes. This task is mostly completed using GCPs (Ground Control Points), although this approach is time consuming as manual intervention is needed. This...
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Authors: Kraft, T.; Advisor: -; Participants: - (2016) - In this paper we present the further evaluation of DLR’s modular airborne camera system MACS-Micro for small unmanned aerial vehicle (UAV). The main focus is on standardized calibration procedures and on photogrammetric workflows. The current prototype consists of an industrial grade frame imaging camera with 12 megapixel resolutions and a compact GNSS/IMU solution which are operated by an embedded computing unit (CPU). The camera was calibrated once pre-flight and several times post-flight over a period of 5 month using a three dimensional test field. The verification of the radiometric quality of the acquired images has been done under controlled static conditions and kinematic cond...
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Authors: Vetrivel, A.; Advisor: -; Participants: - (2016) - Automatic post-disaster mapping of building damage using remote sensing images is an important and time-critical element of disaster management. The characteristics of remote sensing images available immediately after the disaster are not certain, since they may vary in terms of capturing platform, sensor-view, image scale, and scene complexity. Therefore, a generalized method for damage detection that is impervious to the mentioned image characteristics is desirable. This study aims to develop a method to perform grid-level damage classification of remote sensing images by detecting the damage corresponding to debris, rubble piles, and heavy spalling within a defined grid, regardless...
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Authors: Mumbone, Mukendwa; Advisor: -; Participants: - (2015) - One of the objectives of the study was to develop a method for mapping customary land parcels using a UAV. A method was developed and tested in Namibia
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Authors: Duarte, D.; Advisor: -; Participants: Nex, F.; Kerle, N.; Vosselman, G. (2018) - In this paper, three multi-resolution CNN feature fusion approaches are proposed and tested against two baseline (mono-resolution) methods to perform the image classification of building damages. Overall, the results show better accuracy and localization capabilities when fusing multi-resolution feature maps, specifically when these feature maps are merged and consider feature information from the intermediate layers of each of the resolution level networks. Nonetheless, these multi-resolution feature fusion approaches behaved differently considering each level of resolution. In the satellite and aerial (unmanned) cases, the improvements in the accuracy reached 2% while the accuracy i...
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Authors: Stöcker, E.C.; Advisor: -; Participants: - (2017) - UAVs—unmanned aerial vehicles—facilitate data acquisition at temporal and spatial scales that still remain unachievable for traditional remote sensing platforms. However, current legal frameworks that regulate UAVs present significant barriers to research and development. To highlight the importance, impact, and diversity of UAV regulations, this paper provides an exploratory investigation of UAV regulations on the global scale. For this, the methodological approach consists of a research synthesis of UAV regulations, including a thorough literature review and a comparative analysis of national regulatory frameworks. Similarities and contrasting elements in the various national UAV re...
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Authors: Iersel, W.K. van; Advisor: -; Participants: - (2016) - To evaluate floodplain functioning, monitoring of its vegetation is essential. Although airborne imagery is widely applied for this purpose, classification accuracy (CA) remains low for grassland (< 88%) and herbaceous vegetation (<57%) due to the spectral and structural similarity of these vegetation types. Increased availability of Unmanned Aerial Vehicles (UAV) allows low-cost production of high-resolution orthophotos and digital surface models (DSMs). Multi-temporal DSMs and orthophotos may be used as input for an improved classification methodology, using differences in phenological changes between vegetation types. The aim of this study was (1) to evaluate the improvement of the...
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Authors: Whiteside, T.G.; Advisor: -; Participants: - (2016) - The monitoring of mine site rehabilitation, particularly revegetation, involves assessing biophysical parameters over time to determine success or otherwise. Resource and logistical constraints limit the spatial and temporal scale of standard field-based monitoring methods.
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Authors: d'Oleire-Oltmanns, S.; Advisor: -; Participants: - (2016) - The potential of UAV-based data for fine-scaled remote sensing applications has been investigated for several years and is still increasing. The presented study is attached to the field of landform mapping. Mapping and extracting of landforms contributes to different sectors such as agriculture, disaster management and nature conservation. In this study recent experiences and results from working in a nature conservation area are presented. The chosen study area ’Haarmoos’ is located southwest of the lake Abtsdorf, Bavaria and is declared under the European wide Natura 2000 network. Optical imagery and terrain data were analyzed in an integrated approach based on object-based image an...
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Authors: Stratoulias, Dimitris; Advisor: -; Participants: - (2015) - Smallholder farmers contribute to more than 50% of the world’s annual production of cereals, meat and dairy products and they cultivate more than 80% of the total agricultural area in Asia and Sub-Saharan Africa. Conversely, it is estimated that more than 2.5 billion people depend directly on the agricultural sector. Earth Observation has been a tool for agronomists with ever-increasing capability, however, the case of agriculture in low-income countries imposes challenges, for instance in recognizing mixed- and inter-cropping, the small size of the farm plots and lack of sound crop management systems, which increase the uncertainty of information derived from remotely sensed data. Th...
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Authors: Stöcker C.; Advisor: -; Participants: Ho S.; Koeva M.; Nkerabigwi J.; Schmidt C.; Zevenbergen J.; Bennett R. (2018.) - This study sheds light on the needs assessment and design process of UAV-based data acquisition workflows and reveals results of data collection activities and initial UAV test flights in Rwanda. Insights into operational challenges and data quality measures are presented. The paper concludes that the tool of UAV-based data collection seems to offer an answer to the majority of the expressed needs which were assessed with the NGT method. However, the realization of the test flights also reveals three specific challenges that have to be addressed before UAVs can be used for large scale mapping in Rwanda.
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