The use of minimum curvature surface technique in geoid computation processing of Egypt

2011 ◽  
Vol 6 (4) ◽  
pp. 1263-1272 ◽  
Author(s):  
M. Rabah ◽  
M. Kaloop
Keyword(s):  
Curvature Surface ◽  
Geoid Computation ◽  
Minimum Curvature ◽  
Surface Technique

scholarly journals Improvements of 6S Look-Up-Table Based Surface Reflectance Employing Minimum Curvature Surface Method

2020 ◽  
Vol 56 (2) ◽  
pp. 235-248 ◽  
Author(s):  
Kyeong-Sang Lee ◽  
Chang Suk Lee ◽  
Minji Seo ◽  
Sungwon Choi ◽  
Noh-Hun Seong ◽  
...  
Keyword(s):  
Zenith Angle ◽  
Absolute Error ◽  
Surface Reflectance ◽  
Curvature Surface ◽  
Look Up Table ◽  
Satellite Signal ◽  
Spatial Discontinuity ◽  
Reflectance Measurements ◽  
Relative Root ◽  
Minimum Curvature

AbstractWe propose a methodology employing an interpolation technique on the Second Simulation of a Satellite Signal (6S) look-up table (LUT) to improve surface reflectance retrieval using Himawari-8/Advanced Himawari Imager (AHI). A minimum curvature surface (MCS) technique was used to refine the 6S LUT, and the solar zenith angle (SZA) and viewing zenith angle (VZA) increments were narrowed by 0.5°. The interpolation processing time was relatively short, about 3172 s per channel, and the interpolated xa and xb were well represented by the changes in SZA and VZA. An evaluation of the interpolated xa and xb for six cases revealed a relative mean absolute error of less than 5% for all channels and cases; however, a slight difference was evident for higher values of SZA and VZA. To evaluate the surface reflectance, we compared the surface reflectance derived using 6S LUT with that calculated using 6S only. Application of the interpolated 6S LUT showed a lower relative root mean square error (RRMSE) of 0.65% to 9.29% for all channels, than before interpolation. The improvement in surface reflectance measurements increased with the SZA. For a SZA above 75°, the RRMSE improved significantly for all channels (by 11.33–45.1%). In addition, when the MCS method was applied, the surface reflectance measurements improved without spatial discontinuity and showed good agreement with 6S results in a linear profile analyses. Thus, the method proposed can improve LUT based surface reflectance measurements in less time and increase the availability of surface reflectance data based on geostationary satellites.

scholarly journals Potential for Aquifer Storage and Recovery (ASR) in South Bihar, India

2021 ◽  
Vol 13 (6) ◽  
pp. 3502
Author(s):  
Somnath Bandyopadhyay ◽  
Aviram Sharma ◽  
Satiprasad Sahoo ◽  
Kishore Dhavala ◽  
Prabhakar Sharma
Keyword(s):  
Pilot Study ◽  
Environmental Sustainability ◽  
Hard Rock ◽  
Climatic Conditions ◽  
Aquifer Storage And Recovery ◽  
Aquifer Recharge ◽  
Aquifer Storage ◽  
Cropping Season ◽  
Selection Of ◽  
Surface Technique

Among the several options of managed aquifer recharge (MAR) techniques, the aquifer storage and recovery (ASR) is a well-known sub-surface technique to replenish depleted aquifers, which is contingent upon the selection of appropriate sites. This paper explores the potential of ASR for groundwater recharge in the hydrological, hydrogeological, social, and economic context of South Bihar in India. Based on the water samples from more than 137 wells and socio-economic surveys, ASR installations were piloted through seven selected entrepreneurial farmers in two villages of South Bihar. The feasibility of ASR in both hard rock and deep alluvial aquifers was demonstrated for the prominent aquifer types in the marginal alluvial plains of South Bihar and elsewhere. It was postulated through this pilot study that a successful spread of ASR in South Bihar can augment usable water resources for agriculture during the winter cropping season. More importantly, ASR can adapt to local circumstances and challenges under changing climatic conditions. The flexible and participatory approach in this pilot study also allowed the farmers to creatively engage with the design and governance aspects of the recharge pit. The entrepreneurial farmers-led model builds local accountability, creates avenues for private investments, and opens up the space for continued innovation in technology and management, while also committing to resource distributive justice and environmental sustainability.

scholarly journals Uniqueness and nonuniqueness of limits of Teichmüller harmonic map flow

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
James Kohout ◽  
Melanie Rupflin ◽  
Peter M. Topping
Keyword(s):  
Constant Curvature ◽  
Harmonic Map ◽  
Gradient Flow ◽  
Minimal Immersion ◽  
Curvature Surface ◽  
Previous Theory ◽  
Target Manifold ◽  
Harmonic Map Flow

AbstractThe harmonic map energy of a map from a closed, constant-curvature surface to a closed target manifold can be seen as a functional on the space of maps and domain metrics. We consider the gradient flow for this energy. In the absence of singularities, previous theory established that the flow converges to a branched minimal immersion, but only at a sequence of times converging to infinity, and only after pulling back by a sequence of diffeomorphisms. In this paper, we investigate whether it is necessary to pull back by these diffeomorphisms, and whether the convergence is uniform as {t\to\infty}.

The Microsphere Surface Technique for Evaluation of Cochlear Vessels and Circulation

1983 ◽  
Vol 95 (1-4) ◽  
pp. 297-305 ◽  
Author(s):  
A. Axelsson ◽  
C. Angelborg ◽  
H. C. Larsen
Keyword(s):  
Surface Technique

scholarly journals A real time hidden surface technique

1977 ◽  
Vol 20 (4) ◽  
pp. 335-339 ◽  
Author(s):  
P. J. Willis
Keyword(s):  
Real Time ◽  
Surface Technique

scholarly journals Darboux Transforms of a Harmonic Inverse Mean Curvature Surface

Geometry ◽  
2013 ◽  
Vol 2013 ◽  
pp. 1-9
Author(s):  
Katsuhiro Moriya
Keyword(s):  
Mean Curvature ◽  
Curvature Surface ◽  
Surface Of Revolution ◽  
Darboux Transforms

The notion of a generalized harmonic inverse mean curvature surface in the Euclidean four-space is introduced. A backward Bäcklund transform of a generalized harmonic inverse mean curvature surface is defined. A Darboux transform of a generalized harmonic inverse mean curvature surface is constructed by a backward Bäcklund transform. For a given isothermic harmonic inverse mean curvature surface, its classical Darboux transform is a harmonic inverse mean curvature surface. Then a transform of a solution to the Painlevé III equation in trigonometric form is defined by a classical Darboux transform of a harmonic inverse mean curvature surface of revolution.

scholarly journals Kinetic Modelling and Optimizing of Butyl Propionate over a Synthesied Material (Tungstan Phosphoric Acid) Heteropoly Catalyst Using Response Surface Technique

2021 ◽  
Vol 45 (4) ◽  
pp. 273-280
Author(s):  
Raju Kalakuntala ◽  
Srinath Surnani
Keyword(s):  
Experimental Data ◽  
Phosphoric Acid ◽  
Response Surface ◽  
Kinetic Modelling ◽  
Quadratic Model ◽  
Molar Ratio ◽  
Catalyst Loading ◽  
Response Surface Technique ◽  
Optimized Conditions ◽  
Surface Technique

The performance of heteropoly acid i.e., Tungstan phosphoric acid for the synthesis of butyl propionate at optimized conditions. Effect on conversion and yield of propionic acids using the Response Surface Methodology (RSM) were evaluated by different process parameters including catalyst loading, alcohol/acid molar ratio. There were no external and internal mass transmission limits. A quadratic model acquired by the variance study (ANOVA) has been shown to view experimental data successfully with the regression (R2 = 0.94 and R2 = 0.942) coefficients approaching to unity. The pseudo homogeneous kinetic model (PH) validated with experimental data to determine kinetic parameters i.e., activation energy (45.97 kJ/mol) and frequent factor (91319 L/mol-min).

scholarly journals Curvature Surface Magnetic Wheel Climbing Robot with Adaptive Electromagnetic Adhesive Force

2020 ◽  
Vol 25 ◽  
pp. 461-465
Author(s):  
Richit Palangwatanakul ◽  
Apisit Thungsang ◽  
Kaned Thungod ◽  
Arsit Boonyaprapasorn ◽  
Wanachart Borisut ◽  
...  
Keyword(s):  
Adhesive Force ◽  
Curvature Surface ◽  
Climbing Robot
Sign in / Sign up

Export Citation Format

Share Document