Satellite Constellation Image Acquisition Problem: A Case Study

2016 ◽  
pp. 177-197 ◽  
Author(s):  
Krishna Teja Malladi ◽  
Snezana Mitrovic Minic ◽  
Daniel Karapetyan ◽  
Abraham P. Punnen
Keyword(s):  
Image Acquisition ◽  
Satellite Constellation

scholarly journals Optimization of wavelength selection for multispectral image acquisition: a case study of atrial ablation lesions

2018 ◽  
Vol 9 (5) ◽  
pp. 2189 ◽  
Author(s):  
Huda Asfour ◽  
Shuyue Guan ◽  
Narine Muselimyan ◽  
Luther Swift ◽  
Murray Loew ◽  
...  
Keyword(s):  
Image Acquisition ◽  
Multispectral Image ◽  
Wavelength Selection ◽  
Atrial Ablation ◽  
Selection For

scholarly journals UAV PHOTGRAMMETRIC WORKFLOWS: A BEST PRACTICE GUIDELINE

2017 ◽  
Vol XLII-2/W5 ◽  
pp. 237-244 ◽  
Author(s):  
A. Federman ◽  
M. Santana Quintero ◽  
S. Kretz ◽  
J. Gregg ◽  
M. Lengies ◽  
...  
Keyword(s):  
Cultural Heritage ◽  
Best Practice ◽  
Low Cost ◽  
Image Acquisition ◽  
Aerial Image ◽  
Application Process ◽  
Heritage Sites ◽  
Flight Operations ◽  
Data Acquisition And Processing

The increasing commercialization of unmanned aerial vehicles (UAVs) has opened the possibility of performing low-cost aerial image acquisition for the documentation of cultural heritage sites through UAV photogrammetry. The flying of UAVs in Canada is regulated through Transport Canada and requires a Special Flight Operations Certificate (SFOC) in order to fly. Various image acquisition techniques have been explored in this review, as well as well software used to register the data. A general workflow procedure has been formulated based off of the literature reviewed. A case study example of using UAV photogrammetry at Prince of Wales Fort is discussed, specifically in relation to the data acquisition and processing. Some gaps in the literature reviewed highlight the need for streamlining the SFOC application process, and incorporating UAVs into cultural heritage documentation courses.

scholarly journals Advanced 3D Photogrammetric Surface Reconstruction of Extensive Objects by UAV Camera Image Acquisition

Sensors ◽  
2018 ◽  
Vol 18 (9) ◽  
pp. 2815 ◽  
Author(s):  
Michele Calì ◽  
Rita Ambu
Keyword(s):  
Surface Reconstruction ◽  
Large Scale ◽  
Image Acquisition ◽  
Three Dimensional ◽  
Geometric Parameters ◽  
Reconstruction Accuracy ◽  
Camera Image ◽  
Aerial Vehicle ◽  
Euclidean Distances

This paper proposes a replicable methodology to enhance the accuracy of the photogrammetric reconstruction of large-scale objects based on the optimization of the procedures for Unmanned Aerial Vehicle (UAV) camera image acquisition. The relationships between the acquisition grid shapes, the acquisition grid geometric parameters (pitches, image rates, camera framing, flight heights), and the 3D photogrammetric surface reconstruction accuracy were studied. Ground Sampling Distance (GSD), the necessary number of photos to assure the desired overlapping, and the surface reconstruction accuracy were related to grid shapes, image rate, and camera framing at different flight heights. The established relationships allow to choose the best combination of grid shapes and acquisition grid geometric parameters to obtain the desired accuracy for the required GSD. This outcome was assessed by means of a case study related to the ancient arched brick Bridge of the Saracens in Adrano (Sicily, Italy). The reconstruction of the three-dimensional surfaces of this structure, obtained by the efficient Structure-From-Motion (SfM) algorithms of the commercial software Pix4Mapper, supported the study by validating it with experimental data. A comparison between the surface reconstruction with different acquisition grids at different flight heights and the measurements obtained with a 3D terrestrial laser and total station-theodolites allowed to evaluate the accuracy in terms of Euclidean distances.

Recent Trends in 3D Printing of Dental Models

2020 ◽  
pp. 424-444
Author(s):  
Kayalvizhi Mohan
Keyword(s):  
3D Printing ◽  
Rapid Prototyping ◽  
Dental Implants ◽  
Recent Trend ◽  
Image Acquisition ◽  
Different Types ◽  
Dental Models ◽  
Recent Trends ◽  
Printing Techniques

This chapter introduces the recent trend in 3D printing (3DP) in dentistry. The advantage and disadvantages of 3DP are discussed. It elaborates on different types of 3DP techniques involved and their significance. The chapter further discuss about the biomaterial used. It also describes the complete steps involved in 3DP such as image acquisition, modeling, segmentation, and printing techniques. The merits and demerits of the different methodologies pertaining to steps involved in 3DP are illustrated. Rapid prototyping in dental implants is discussed in detail. It ends with review of a case study in implementing the technique.

Recent Trends in 3D Printing of Dental Models

2019 ◽  
pp. 217-237 ◽  
Author(s):  
Kayalvizhi Mohan
Keyword(s):  
3D Printing ◽  
Rapid Prototyping ◽  
Dental Implants ◽  
Recent Trend ◽  
Image Acquisition ◽  
Different Types ◽  
Dental Models ◽  
Recent Trends ◽  
Printing Techniques

This chapter introduces the recent trend in 3D printing (3DP) in dentistry. The advantage and disadvantages of 3DP are discussed. It elaborates on different types of 3DP techniques involved and their significance. The chapter further discuss about the biomaterial used. It also describes the complete steps involved in 3DP such as image acquisition, modeling, segmentation, and printing techniques. The merits and demerits of the different methodologies pertaining to steps involved in 3DP are illustrated. Rapid prototyping in dental implants is discussed in detail. It ends with review of a case study in implementing the technique.

The Genesis and Internal Dynamics of El Salvador's People's Revolutionary Army, 1970–1976

2014 ◽  
Vol 38 (01) ◽  
pp. 102-129
Author(s):  
ALBERTO MARTÍN ÁLVAREZ ◽  
EUDALD CORTINA ORERO
Keyword(s):  
Latin America ◽  
El Salvador ◽  
Early Years ◽  
Left Wing ◽  
Internal Dynamics ◽  
Internal Coherence ◽  
The 1960S

AbstractUsing interviews with former militants and previously unpublished documents, this article traces the genesis and internal dynamics of the Ejército Revolucionario del Pueblo (People's Revolutionary Army, ERP) in El Salvador during the early years of its existence (1970–6). This period was marked by the inability of the ERP to maintain internal coherence or any consensus on revolutionary strategy, which led to a series of splits and internal fights over control of the organisation. The evidence marshalled in this case study sheds new light on the origins of the armed Salvadorean Left and thus contributes to a wider understanding of the processes of formation and internal dynamics of armed left-wing groups that emerged from the 1960s onwards in Latin America.

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