scholarly journals COEVRAGE ESTIMATION OF GEOSENSOR IN 3D VECTOR ENVIRONMENTS

2014 ◽  
Vol XL-2/W3 ◽  
pp. 1-6 ◽  
Author(s):  
A. Afghantoloee ◽  
S. Doodman ◽  
F. Karimipour ◽  
M. A. Mostafavi
Keyword(s):  
Case Studies ◽  
Sensor Deployment ◽  
Surface Model ◽  
Digital Surface Model ◽  
Vector Data ◽  
Spatial Coverage ◽  
Urban Models ◽  
Deployment Optimization ◽  
Different Levels

Sensor deployment optimization to achieve the maximum spatial coverage is one of the main issues in Wireless geoSensor Networks (WSN). The model of the environment is an imperative parameter that influences the accuracy of geosensor coverage. In most of recent studies, the environment has been modeled by Digital Surface Model (DSM). However, the advances in technology to collect 3D vector data at different levels, especially in urban models can enhance the quality of geosensor deployment in order to achieve more accurate coverage estimations. This paper proposes an approach to calculate the geosensor coverage in 3D vector environments. The approach is applied on some case studies and compared with DSM based methods.

scholarly journals AUTOMATIC RECONSTRUCTION OF ROOF MODELS FROM BUILDING OUTLINES AND AERIAL IMAGE DATA

2019 ◽  
Vol 59 (5) ◽  
pp. 448-457
Author(s):  
Vojtěch Hron ◽  
Lena Halounová
Keyword(s):  
Image Data ◽  
Aerial Survey ◽  
Aerial Image ◽  
Surface Model ◽  
Digital Surface Model ◽  
Multiple Datasets ◽  
Building Models ◽  
The Creation ◽  
Near Future ◽  
Different Levels

The knowledge of roof shapes is essential for the creation of 3D building models. Many experts and researchers use 3D building models for specialized tasks, such as creating noise maps, estimating the solar potential of roof structures, and planning new wireless infrastructures. Our aim is to introduce a technique for automating the creation of topologically correct roof building models using outlines and aerial image data. In this study, we used building footprints and vertical aerial survey photographs. Aerial survey photographs enabled us to produce an orthophoto and a digital surface model of the analysed area. The developed technique made it possible to detect roof edges from the orthophoto and to categorize the edges using spatial relationships and height information derived from the digital surface model. This method allows buildings with complicated shapes to be decomposed into simple parts that can be processed separately. In our study, a roof type and model were determined for each building part and tested with multiple datasets with different levels of quality. Excellent results were achieved for simple and medium complex roofs. Results for very complex roofs were unsatisfactory. For such structures, we propose using multitemporal images because these can lead to significant improvements and a better roof edge detection. The method used in this study was shared with the Czech national mapping agency and could be used for the creation of new 3D modelling products in the near future.

scholarly journals Achieving Quality Forest and Landscape Restoration in the Tropics

Forests ◽  
2020 ◽  
Vol 11 (8) ◽  
pp. 820 ◽  
Author(s):  
Liz Ota ◽  
Robin L. Chazdon ◽  
John Herbohn ◽  
Nestor Gregorio ◽  
Sharif A. Mukul ◽  
...  
Keyword(s):  
Case Studies ◽  
Environmental Conditions ◽  
Landscape Restoration ◽  
Spatial Coverage ◽  
The World ◽  
The Tropics ◽  
Incremental Process ◽  
Over Time

Forest and landscape restoration (FLR) is being carried out across the world to meet ambitious global goals. However, the scale of these efforts combined with the timeframe in which they are supposed to take place may compromise the quality of restoration, and thus limit the persistence of restoration on the landscape. This paper presents a synthesis of ten case studies identified as FLR to critically analyse implemented initiatives, their outcomes, and main challenges, with an eye to improving future efforts. The identified FLR projects are diverse in terms of their spatial coverage, objectives; types of interventions; and initial socioeconomic, institutional, and environmental conditions. The six principles of FLR—which have been widely adopted in theory by large global organisations—are inadequately addressed across the initiatives presented here. The identified FLR project or interventions, although expected to offer diverse benefits, face many challenges including the lack of long-term sustainability of project interventions, limited uptake by regional and national agencies, limited monitoring, reporting and learning, poor governance structures, and technical barriers, which are mainly owing to institutional weaknesses. On the basis of these cases, we propose that the best pathway to achieving FLR is via an incremental process in which a smaller number of more achievable objectives are set and implemented over time, rather than setting highly ambitious targets that implementers struggle to achieve.

EVALUASI KETELITIAN HORIZONTAL DARI CITRA TEGAK SATELIT RESOLUSI SANGAT TINGGI MENGGUNAKAN SRTM DAN TERRASAR-X UNTUK PEMETAAN SKALA BESAR

2018 ◽  
Vol 2 ◽  
pp. 535
Author(s):  
Maundri Prihanggo
Keyword(s):  
Control Point ◽  
Ground Control ◽  
Surface Model ◽  
Digital Surface Model ◽  
Check Point ◽  
Ground Control Point

<p>Saat ini, citra satelit resolusi sangat tinggi digunakan dalam berbagai macam aplikasi, terutama pemetaan skala besar. Sebelum dapat digunakan, citra satelit tersebut harus diorthorektifikasi terlebih dahulu. Data <em>Digital Surface Model </em>(DSM) dan <em>Ground Control Point</em> (GCP) adalah dua data utama yang diperlukan saat melakukan orthorektifikasi. Perbedaan data DSM yang digunakan akan menghasilkan perbedaan nilai ketelitian horizontal pada kedua citra tegak hasil orthorektifikasi. Pada penelitian ini digunakan dua jenis DSM yaitu SRTM dan Terrasar-X. Ketelitian vertikal dari SRTM adalah 90 m sedangkan ketelitian vertikal dari Terrasar-X adalah 12,5 m. Penelitian ini berlokasi di Wilayah Buli, Kabupaten Halmahera Timur, Provinsi Maluku. Terdapat tiga sensor citra satelit yang digunakan yaitu Pleiades, Quickbird dan Worldview-2 yang digunakan pada lokasi penelitian. Total GCP yang digunakan adalah 33 titik, tiap titiknya diukur dengan melakukan pengamatan geodetik dan memiliki ketelitian horizontal ≤15 cm dan ketelitian vertikal ≤30 cm. Ketelitian horizontal dari citra tegak satelit resolusi sangat tinggi diperoleh dengan melakukan uji terhadap Independent Check Point (ICP). Total ICP yang digunakan adalah 12 titik, tiap titik ICP diukur dengan metode dan standar yang sama dengan titik GCP. Ketelitian horizontal dengan Circular Error (CE 90) dari citra tegak satelit menggunakan data SRTM adalah 18,856 m sedangkan ketelitian horizontal dengan Circular Error (CE 90) dari citra tegak satelit menggunakan data Terrasar-X adalah 2.168 m . Hasil dari penelitian ini membuktikan bahwa ketelitian vertikal data DSM yang digunakan memberikan pengaruh pada citra tegak satelit hasil orthorektifikasi tersebut. Mengacu pada Peraturan Kepala BIG nomor 15 tahun 2014, citra tegak satelit hasil orthorektifikasi menggunakan data Terrasar-X sebagai DSM memenuhi ketelitian horizontal peta dasar kelas 3 skala 1:5.000 sedangkan citra tegak satelit hasil orthorektifikasi menggunakan data SRTM sebagai DSM tidak dapat memenuhi ketelitian horizontal peta dasar skala besar.</p><p><strong>Kata kunci:</strong> orthorektifikasi, DSM, ketelitian horizontal</p>

Measuring historical flooding and erosion in Goodnews Bay using datasets commonly available to Alaska communities

Shore & Beach ◽  
2020 ◽  
pp. 3-13
Author(s):  
Richard Buzard ◽  
Christopher Maio ◽  
David Verbyla ◽  
Nicole Kinsman ◽  
Jacquelyn Overbeck
Keyword(s):  
Rural Communities ◽  
Coastal Communities ◽  
Aerial Imagery ◽  
Coastal Hazards ◽  
Surface Model ◽  
Digital Surface Model ◽  
Wave Impact ◽  
Information Gap ◽  
Quantitative Analyses ◽  
Gnss Measurements

Coastal hazards are of increasing concern to many of Alaska’s rural communities, yet quantitative assessments remain absent over much of the coast. To demonstrate how to fill this critical information gap, an erosion and flood analysis was conducted for Goodnews Bay using an assortment of datasets that are commonly available to Alaska coastal communities. Measurements made from orthorectified aerial imagery from 1957 to 2016 show the shoreline eroded 0 to 15.6 m at a rate that posed no immediate risk to current infrastructure. Storm surge flood risk was assessed using a combination of written accounts, photographs of storm impacts, GNSS measurements, hindcast weather models, and a digital surface model. Eight past storms caused minor to major flooding. Wave impact hour calculations showed that the record storm in 2011 doubled the typical annual wave impact hours. Areas at risk of erosion and flooding in Goodnews Bay were identified using publicly available datasets common to Alaska coastal communities; this work demonstrates that the data and tools exist to perform quantitative analyses of coastal hazards across Alaska.

scholarly journals New Orthophoto Generation Strategies from UAV and Ground Remote Sensing Platforms for High-Throughput Phenotyping

2021 ◽  
Vol 13 (5) ◽  
pp. 860
Author(s):  
Yi-Chun Lin ◽  
Tian Zhou ◽  
Taojun Wang ◽  
Melba Crawford ◽  
Ayman Habib
Keyword(s):  
Remote Sensing ◽  
Control Strategies ◽  
Target Function ◽  
Canopy Cover ◽  
Surface Model ◽  
Flowering Date ◽  
Sensing Platforms ◽  
Geolocation Accuracy ◽  
New Strategies

Remote sensing platforms have become an effective data acquisition tool for digital agriculture. Imaging sensors onboard unmanned aerial vehicles (UAVs) and tractors are providing unprecedented high-geometric-resolution data for several crop phenotyping activities (e.g., canopy cover estimation, plant localization, and flowering date identification). Among potential products, orthophotos play an important role in agricultural management. Traditional orthophoto generation strategies suffer from several artifacts (e.g., double mapping, excessive pixilation, and seamline distortions). The above problems are more pronounced when dealing with mid- to late-season imagery, which is often used for establishing flowering date (e.g., tassel and panicle detection for maize and sorghum crops, respectively). In response to these challenges, this paper introduces new strategies for generating orthophotos that are conducive to the straightforward detection of tassels and panicles. The orthophoto generation strategies are valid for both frame and push-broom imaging systems. The target function of these strategies is striking a balance between the improved visual appearance of tassels/panicles and their geolocation accuracy. The new strategies are based on generating a smooth digital surface model (DSM) that maintains the geolocation quality along the plant rows while reducing double mapping and pixilation artifacts. Moreover, seamline control strategies are applied to avoid having seamline distortions at locations where the tassels and panicles are expected. The quality of generated orthophotos is evaluated through visual inspection as well as quantitative assessment of the degree of similarity between the generated orthophotos and original images. Several experimental results from both UAV and ground platforms show that the proposed strategies do improve the visual quality of derived orthophotos while maintaining the geolocation accuracy at tassel/panicle locations.

scholarly journals Assessment of the EUMETSAT Multi Decadal Land Surface Albedo Data Record from Meteosat Observations

2021 ◽  
Vol 13 (10) ◽  
pp. 1992
Author(s):  
Alessio Lattanzio ◽  
Michael Grant ◽  
Marie Doutriaux-Boucher ◽  
Rob Roebeling ◽  
Jörg Schulz
Keyword(s):  
Land Surface ◽  
Surface Albedo ◽  
Time Range ◽  
Essential Variable ◽  
Spatial Coverage ◽  
Data Record ◽  
Moderate Resolution Imaging Spectroradiometer ◽  
Cloud Mask ◽  
Cloud Screening

Surface albedo, defined as the ratio of the surface-reflected irradiance to the incident irradiance, is one of the parameters driving the Earth energy budget and it is for this reason an essential variable in climate studies. Instruments on geostationary satellites provide suitable observations allowing long-term monitoring of surface albedo from space. In 2012, EUMETSAT published Release 1 of the Meteosat Surface Albedo (MSA) data record. The main limitation effecting the quality of this release was non-removed clouds by the incorporated cloud screening procedure that caused too high albedo values, in particular for regions with permanent cloud coverage. For the generation of Release 2, the MSA algorithm has been replaced with the Geostationary Surface Albedo (GSA) one, able to process imagery from any geostationary imager. The GSA algorithm exploits a new, improved, cloud mask allowing better cloud screening, and thus fixing the major limitation of Release 1. Furthermore, the data record has an extended temporal and spatial coverage compared to the previous release. Both Black-Sky Albedo (BSA) and White-Sky Albedo (WSA) are estimated, together with their associated uncertainties. A direct comparison between Release 1 and Release 2 clearly shows that the quality of the retrieval improved significantly with the new cloud mask. For Release 2 the decadal trend is less than 1% over stable desert sites. The validation against Moderate Resolution Imaging Spectroradiometer (MODIS) and the Southern African Regional Science Initiative (SAFARI) surface albedo shows a good agreement for bright desert sites and a slightly worse agreement for urban and rain forest locations. In conclusion, compared with MSA Release 1, GSA Release 2 provides the users with a significantly more longer time range, reliable and robust surface albedo data record.

scholarly journals The Importance of Environmental Factors in the Planning of Container Terminals: The Case Study of the Port of Augusta

2021 ◽  
Vol 11 (5) ◽  
pp. 2153
Author(s):  
Nadia Giuffrida ◽  
Maja Stojaković ◽  
Elen Twrdy ◽  
Matteo Ignaccolo
Keyword(s):  
Environmental Impact ◽  
Container Terminal ◽  
Decision Support Tool ◽  
Container Terminals ◽  
Mitigation Measures ◽  
Support Tool ◽  
Clean Environment ◽  
Different Levels

Container terminals are the main hubs of the global supply chain but, conversely, they play an important role in energy consumption, environmental pollution and even climate change due to carbon emissions. Assessing the environmental impact of this type of port terminal and choosing appropriate mitigation measures is essential to pursue the goals related to a clean environment and ensuring a good quality of life of the inhabitants of port cities. In this paper the authors present a Terminal Decision Support Tool (TDST) for the development of a container terminal that considers both operation efficiency and environmental impacts. The TDST provides environmental impact mitigation measures based on different levels of evolution of the port’s container traffic. An application of the TDST is conducted on the Port of Augusta (Italy), a port that is planning infrastructural interventions in coming years in order to gain a new role as a reference point for container traffic in the Mediterranean.

scholarly journals Integration of Satellite Data with High Resolution Ratio: Improvement of Spectral Quality with Preserving Spatial Details

Sensors ◽  
2018 ◽  
Vol 18 (12) ◽  
pp. 4418 ◽  
Author(s):  
Aleksandra Sekrecka ◽  
Michal Kedzierski
Keyword(s):  
High Ratio ◽  
Data Sets ◽  
Spectral Quality ◽  
Local Statistics ◽  
Panchromatic Image ◽  
Urbanized Area ◽  
Fusion Methods ◽  
Spatial Quality ◽  
Different Levels

Commonly used image fusion techniques generally produce good results for images obtained from the same sensor, with a standard ratio of spatial resolution (1:4). However, an atypical high ratio of resolution reduces the effectiveness of fusion methods resulting in a decrease in the spectral or spatial quality of the sharpened image. An important issue is the development of a method that allows for maintaining simultaneous high spatial and spectral quality. The authors propose to strengthen the pan-sharpening methods through prior modification of the panchromatic image. Local statistics of the differences between the original panchromatic image and the intensity of the multispectral image are used to detect spatial details. The Euler’s number and the distance of each pixel from the nearest pixel classified as a spatial detail determine the weight of the information collected from each integrated image. The research was carried out for several pan-sharpening methods and for data sets with different levels of spectral matching. The proposed solution allows for a greater improvement in the quality of spectral fusion, while being able to identify the same spatial details for most pan-sharpening methods and is mainly dedicated to Intensity-Hue-Saturation based methods for which the following improvements in spectral quality were achieved: about 30% for the urbanized area and about 15% for the non-urbanized area.

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