Detection of spatial, temporal, and spectral surface changes in the Ny-Ålesund area 79° N, Svalbard, using a low cost multispectral camera in combination with spectroradiometer measurements

2003 ◽  
Vol 28 (28-32) ◽  
pp. 1229-1239 ◽  
Author(s):  
Jørgen Hinkler ◽  
Jon Børre Ørbæk ◽  
Birger Ulf Hansen
Author(s):  
J. Kern ◽  
M. Weinmann ◽  
S. Wursthorn

After scanning or reconstructing the geometry of objects, we need to inspect the result of our work. Are there any parts missing? Is every detail covered in the desired quality? We typically do this by looking at the resulting point clouds or meshes of our objects on-screen. What, if we could see the information directly visualized on the object itself? Augmented reality is the generic term for bringing virtual information into our real environment. In our paper, we show how we can project any 3D information like thematic visualizations or specific monitoring information with reference to our object onto the object’s surface itself, thus augmenting it with additional information. For small objects that could for instance be scanned in a laboratory, we propose a low-cost method involving a projector-camera system to solve this task. The user only needs a calibration board with coded fiducial markers to calibrate the system and to estimate the projector’s pose later on for projecting textures with information onto the object’s surface. Changes within the projected 3D information or of the projector’s pose will be applied in real-time. Our results clearly reveal that such a simple setup will deliver a good quality of the augmented information.


2020 ◽  
Vol 58 (9) ◽  
pp. 645-652
Author(s):  
Euije Jo ◽  
Dongwan Kim ◽  
Jae-Young Leem

Because of their simplicity and low equipment costs, various oxidation methods can be used to create metal oxides, but they still require long processing times and/or high temperatures. In this study, a new electrochemical oxidation (ECO) method, which oxidizes metal in DI water with a constant flowing current to both the cathode and anode, was developed to overcome the disadvantages of conventional oxidation methods. The mechanism of the ECO method is discussed. Metallic Zn films were oxidized by the ECO method in DI water for 1 h. The DI water temperature was varied from 30 to 90 <sup>o</sup>C to determine the optimal temperature for the ECO process. Increasing the temperature of the DI water led to distinct surface changes in the disk-shaped Zn plate. The intensity of diffraction peaks from the ZnO (002) plane gradually increased from 31.67 to 2806.48. The structural and optical properties of the ZnO thin film were enhanced as the temperature of the DI water approached 90 <sup>o</sup>C, which means that a high-quality ZnO thin film was synthesized using the ECO method at lower temperatures and shorter processing time compared with established oxidation methods. These results confirm the ECO method can be useful for the low-cost fabrication of transparent and flexible optoelectronic devices.


Author(s):  
Jorge Tadeu Fim Rosas ◽  
Francisco de Assis de Carvalho Pinto ◽  
Daniel Marçal de Queiroz ◽  
Flora Maria de Melo Villar ◽  
Domingos Sárvio Magalhães Valente ◽  
...  

2014 ◽  
Author(s):  
Patrick Oduor ◽  
Genki Mizuno ◽  
Robert Olah ◽  
Achyut K. Dutta

Author(s):  
E. Nocerino ◽  
M. Dubbini ◽  
F. Menna ◽  
F. Remondino ◽  
M. Gattelli ◽  
...  

Multispectral imaging is a widely used remote sensing technique, whose applications range from agriculture to environmental monitoring, from food quality check to cultural heritage diagnostic. A variety of multispectral imaging sensors are available on the market, many of them designed to be mounted on different platform, especially small drones. This work focuses on the geometric and radiometric characterization of a brand-new, lightweight, low-cost multispectral camera, called MAIA. The MAIA camera is equipped with nine sensors, allowing for the acquisition of images in the visible and near infrared parts of the electromagnetic spectrum. Two versions are available, characterised by different set of band-pass filters, inspired by the sensors mounted on the WorlView-2 and Sentinel2 satellites, respectively. The camera details and the developed procedures for the geometric calibrations and radiometric correction are presented in the paper.


2021 ◽  
Author(s):  
Lea Epple ◽  
Andreas Kaiser ◽  
Marcus Schindewolf ◽  
Anette Eltner

&lt;p&gt;Soil erosion as a major environmental challenge, plays a central role in land degradation. Accurate erosion rates assessment and information on erosion, deposition and on occurring processes are important to support soil protection and recovery strategies.&lt;/p&gt;&lt;p&gt;Due to the complexity, variability and discontinuity of erosional processes, model approaches to predict soil erosion are non-transferable to different temporal and spatial scales. Present process-based models are only valid for the particular observation scale which they were parameterized and validated for. In reality processes occur (e.g. spontaneous rill initiation) which are only to some extent reproducible, resulting in an incomplete process description. While model parameterization in the past was limited by the availability and resolution of data, constant development of data assessment technologies help overcome these confines. Time and cost in collecting data decreases, computing power is constantly expended and both the temporal and spatial resolution offer new possibilities on new scales.&lt;/p&gt;&lt;p&gt;Addressing the issue &amp;#8216;data overhaul models&amp;#8217; we present a unique experimental setup, including flow velocity, erosion and deposition measurements at nested temporal and spatial scales, acquired using high resolution photogrammetric data (RGB and thermal) and structure from motion techniques. At the micro plot scale (3 m&lt;sup&gt;2&lt;/sup&gt;), we perform rainfall simulations, monitored with up to eleven cameras. Using time lapse intervals of 10-20 seconds processes of pool formation and aggregate breakdown are observed. At the hillslope scale (60 m&lt;sup&gt;2&lt;/sup&gt;), we installed a permanent setup &amp;#8211; three rigs at three slope positions at four meter height, each equipped with five synchronized RGB cameras, a RGB video-camera and a low cost thermal camera. To capture changes in soil surface during rainfall events, time lapse images are triggered by a low-cost rain gauge. Soil surface changes at the small catchment scale (4&amp;#160;ha) are measured by taking UAV-images before and after rainfall events. These observations are used as parameterization, calibration and validation for modelled soil surface changes and erosion fluxes, using Erosion3D and FullSWOF.&lt;/p&gt;&lt;p&gt;The continuous development and improvement of soil erosion assessment techniques leads to spatially and temporally highly resolved information on different scales. Eventually the adjustment of the erosion models can enable a cross-scale description and validation of scale-dependent processes, offering new perspectives on both interconnectivity of sediment transport and the relationship between event frequency and magnitude.&lt;/p&gt;


Author(s):  
Y. L. Chen ◽  
S. Fujlshiro

Metastable beta titanium alloys have been known to have numerous advantages such as cold formability, high strength, good fracture resistance, deep hardenability, and cost effectiveness. Very high strength is obtainable by precipitation of the hexagonal alpha phase in a bcc beta matrix in these alloys. Precipitation hardening in the metastable beta alloys may also result from the formation of transition phases such as omega phase. Ti-15-3 (Ti-15V- 3Cr-3Al-3Sn) has been developed recently by TIMET and USAF for low cost sheet metal applications. The purpose of the present study was to examine the aging characteristics in this alloy.The composition of the as-received material is: 14.7 V, 3.14 Cr, 3.05 Al, 2.26 Sn, and 0.145 Fe. The beta transus temperature as determined by optical metallographic method was about 770°C. Specimen coupons were prepared from a mill-annealed 1.2 mm thick sheet, and solution treated at 827°C for 2 hr in argon, then water quenched. Aging was also done in argon at temperatures ranging from 316 to 616°C for various times.


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