Detection of tsunami-induced changes using generalized improved fuzzy radial basis function neural network     

Akansha Mehrotra  Krishna Kant Singh  M. J. Nigam  Kirat Pal 《Natural Hazards》2015,77(1):367-381

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Extraction of geomorphological features using radarsat data     

Ashok Kaushal  Yogesh Singh 《Journal of the Indian Society of Remote Sensing》2006,34(3):299-307

A study was undertaken to evaluate the potential of RADARSAT SAR data (Standard-7 and Wide-2 beam positions) for delineating the geomophological units in Itanagar Capital Complex of Arunachal Pradesh, India. Principal Component Analysis (PCA) has been applied to Standard-7 and Wide-2 data with incidence angle 45° – 49° and 31 ° – 39° respectively. The resulting components yield imagery that highlights the Geomorphological units. The area of investigation has been classified into five geomophological units’ viz., High relief structural hills, low relief structural hills, low relief rugged hills, piedmont and intermontane valley. The surface roughness can be observed by studying the difference of the responses from different incidence angles. Wide-2 beam position was found to be more useful for identifying features in flat terrain, and Standard-7 beam position data for features of high relief.  相似文献   

atmospheric corrections to thermal IR data for estimation of land surface temperature     

Yogesh Kant  K V S Badarinath 《Journal of the Indian Society of Remote Sensing》1998,26(3):113-120

Satellite data provides important inputs far estimating regional surface emisslviiy and surface temperature. The methodology for estimation of emissivity over heterogeneous areas is based on the calculation of fraction vegetation cover per pixel taking NDVI, reflectances of pure pixels as input. The surface temperature is calculated using a sptit-window equation, which depends on atmospheric water vapour, viewing angle and channel surface emissivities. In the present study model coefficients for atmospheric corrections to NOAA AVHRR thermal data Fqr tropical atmospheres have been derived with a view to operationally use the methodolpgy for generating land surface temperature information from satellite data. The results of the study show that the estimated temperature values are comparable with the ctimatological values over the region Suggesting the possible use of the methodology.  相似文献   

Structural analyses of the crystalline rocks between Dirang and Tawang,West Kameng district,Arunachal Himalaya     

Hari B. Srivastava  Vaibhava Srivastava  Rajesh K. Srivastava  Chandra Kant Singh 《Journal of the Geological Society of India》2011,78(1):45-56

In Kameng Valley of Arunachal Pradesh, the crystalline rocks of Se La Group of Higher Himalaya are thrust over the Lesser Himalayan rocks of Dirang Formation, Bomdila Group along the Main Central Thrust and exhibit well preserved structures on macro- to microscopic scales. Detailed analysis of structures reveals that the rocks of the area have suffered four phases of deformation D₁, D₂, D₃ and D₄. These structures have been grouped into (i) early structures (ii) structures related to progressive ductile thrusting and (iii) late structures. The early structures which developed before thrusting formed during D₁ and D₂ phases of deformation, synchronous to F₁ and F₂ phases of folding respectively. The structures related to progressive ductile shearing developed during D₃ phase of deformation, when the emplacement of the crystalline rocks took place over the rocks of Dirang Formation along the Main Central Thrust. Different asymmetric structures/kinematic indicators developed during this ductile/brittle-ductile regime suggest top-to-SSW sense of movement of the crystalline rocks of the area. D₄ is attributed to brittle deformation. Based on satellite data two new thrusts, i.e. Tawang and Se La thrusts have been identified parallel to Main Central Thrust, which are suggestive of imbricate thrusting. Strain analysis from the quartz grains of the gneissic rocks reveals constriction type of strain ellipsoid where k value is higher near the MCT, gradually decreases towards the north. Further, the dynamic analysis carried out on the mesoscopic ductile and brittle-ductile shear zones suggest a NNE-SSW horizontal compression corresponding to the direction of northward movement of Indian Plate.  相似文献   

Fast Transients with the Square Kilometre Array and its Pathfinders: An Indian Perspective     

Yashwant Gupta  Poonam Chandra  Manjari Bagchi  Niruj M. Ramanujam  Yogesh Maan  Avinash A. Deshpande  Siddhartha Bhattacharyya 《Journal of Astrophysics and Astronomy》2016,37(4):37

In the rapidly developing field of study of the transient sky, fast radio transients are perhaps the most exciting objects of scrutiny at present. The SKA, with its wide field-of-view and significant improvement in sensitivity over existing facilities, is expected to detect a plethora of fast transients which, in addition to help resolve the mysteries surrounding their nature and origin, will also lead to other interesting applications in astrophysics. We explore some of these possibilities here, and also emphasize the current status and future plans of the Indian community working in this area, in the context of ongoing work and extension of this to the SKA.  相似文献   

Land Surface Emissivity and Temperature Determination Using NOAA‐AVHRR Data     

Yogesh Kant  K. V.S. Badarinath 《国际地球制图》2013,28(1):64-69

Abstract

Studies on land surface processes using remote sensing data gains importance in the context of Geosphere Biosphere Programme. Present study addresses the applicability of split‐window method, in a tropical environment for mapping of surface temperature over heterogeneous surface from satellite data. The accuracy of the method is about +2.2°K, which is reasonable value taking into account the atmospheric attenuation in tropical environment. An attempt has been made to derive emissivity from normalized difference vegetation index (NDVI) by taking into account the fraction of vegetation cover of each pixel, which is determined by satellite data. The emissivity values estimated from satellite data found to be in reasonable agreement with an estimated error of less than 1%. The results of the study indicate the potential use of NDVI as a modulating parameter in the land surface temperature estimation from satellite data.  相似文献   

Demographic development in an Indian state: a case study of Rajasthan     

Kant S 《Population geography : a journal of the Association of Population Geographers of India》1990,12(1-2):11-26

"The paper attempts to analyse the patterns of and trends in demographic development in Rajasthan state [India] by employing the indices of urbanization, literacy and occupational diversification.... An effort has also been made to define the concept of demographic development...." Demographic development is defined as improvement in the quality of the population in a given area.  相似文献   

Neoproterozoic age based on microbiotas from the Raipur Group of Baradwar sub-basin,Chhattisgarh     

Rupendra Babu  Veeru Kant Singh  Naresh Chandra Mehrotra 《Journal of the Geological Society of India》2014,84(4):442-448

An assemblage of structurally preserved organic-walled microfossils (OWMs) from the macerated residue of black carbonaceous shale belonging to Saradih Formation, the youngest carbonate horizon of the Raipur Group, Chhattisgarh Supergroup exposed at on the right bank of Mahanadi River, NE of Sarangarh township in Raigarh district, Chhattisgarh is being reported for the first time. The assemblage is comprised of 19 taxa of 13 genera belong to eukaryotes and prokaryotes viz. Leiosphaeridia, Stictosphaeridium, Dictyotidium, Synsphaeridium, Symplassosphaeridium, Satka, Trachysphaeridium, Goniosphaeridium, Trachyhystrichosphaera, Vandalosphaeridium, Siphonophycus, Oscillatoriopsis and Polythrichoides. The comprehensive account of recovered microbiotic assemblage can be correlated with globally known Neoproterozoic (early Cryogenian) assemblages, deposited in tidal complexes of shallow sea.  相似文献   

Size Distributions of Aerosol Sulfates and Nitrates in Beijing during the 2008 Olympic Games: Impacts of Pollution Control Measures and Regional Transport   总被引：1，自引：0，他引：1  

WANG Xinfeng  WANG Tao  Ravi Kant PATHAK  Mattias HALLQUIST  GAO Xiaomei  NIE Wei  XUE Likun  GAO Jian  GAO Rui  ZHANG Qingzhu  WANG Wenxing  WANG Shulan  CHAI Fahe  CHEN Yizhen 《大气科学进展》2013,30(2):341-353

For the 2008 Olympic Games, drastic control measures were implemented on industrial and urban emissions of sulfur dioxide (SO₂), nitrogen oxides (NO_x) and other pollutants to address the issues of poor air quality in Beijing. To investigate the effects of SO₂ and NO_x reductions on the particulate sulfate and nitrate concentrations as well as their size distributions, size-segregated aerosol samples were collected using micro-orifice uniform deposit impactors (MOUDIs) at urban and downwind rural sites in Beijing before and after full-scale controls. During the sampling period, the mass concentrations of fine particles (PM_1.8) at the urban and rural sites were 94.0 and 85.9 μg m^-3, respectively. More than 90% of the sulfates and ～60% of nitrates formed as fine particles. Benefiting from the advantageous meteorological conditions and the source controls, sulfates were observed in rather low concentrations and primarily in condensation mode during the Olympics. The effects of the control measures were separately analyzed for the northerly and the southerly air-mass-dominated days to account for any bias. After the control measures were implemented, PM, sulfates, and nitrates were significantly reduced when the northerly air masses prevailed, with a higher percentage of reduction in larger particles. The droplet mode particles, which dominated the sulfates and nitrates before the controls were implemented, were remarkably reduced in mass concentration after the control measures were implemented. Nevertheless, when the polluted southerly air masses prevailed, the local source control measures in Beijing did not effectively reduce the ambient sulfate concentration due to the enormous regional contribution from the North China Plain.  相似文献   

Geology,structural and exhumation history of the Higher Himalayan Crystallines in Kumaon Himalaya,India     

R. C. Patel  Vikas Adlakha  Paramjeet Singh  Yogesh Kumar  Nand Lal 《Journal of the Geological Society of India》2011,77(1):47-72

The crystallines in the Kumaon Himalaya, India are studied along Goriganga, Darma and Kaliganga valleys and found to be composed of two high-grade metamorphic gneiss sheets i.e. the Higher Himalayan Crystalline (HHC) and Lesser Himalayan Crystalline (LHC) zones. These were tectonically extruded as a consequence of the southward directed propagation of crustal deformation in the Indian plate margin. The HHC and its cover rocks i.e. the Tethyan Sedimentary Zone (TSZ) are exposed through tectonic zones within the hinterland of Kumaon Himalaya. The HHC records history of at least one episode of pre-Himalayan deformation (D₁), three episodes of Himalayan deformation (D₂, D₃, D₄). The rocks of the HHC in Kumaon Himalaya are thoroughly transposed by D₂ deformation into NW-SE trending S_m (S₁+S₂). The extent of transposition and a well-developed NE-plunging L₂ lineation indicate intense strain during D₂ throughout the studied portion of the HHC. Ductile flow continued, resulting in rotation of F₁ and F₂ folds due NE-direction and NW-SE plunging F₃ folds within the HHC. The over thickened crystalline was finally, superimposed by late-to-post collisional brittle-ductile deformation (D₄) and exposed the rocks to rapid erosion.  相似文献