Dharmendra Singh | Osmania University (original) (raw)
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Papers by Dharmendra Singh
Tectonophysics, 1994
Fundamental-mode surface wave generated by twelve earthquakes, which occurred in northeastern Ind... more Fundamental-mode surface wave generated by twelve earthquakes, which occurred in northeastern India and nearby regions and were recorded at the Shillong (SHL) and Chiengmai (CHG) seismic stations are used to determine the shear wave velocity structure beneath these regions. The Frequency Time Analysis method is used to determine the group velocities for periods ranging from 4 to 50 s for fundamental-mode Rayleigh and Love waves. A high shear wave velocity (4.2-4.7 km s -1) is estimated in the lower 30-34 km of the crust. Crustal thickness is found to vary from 36 to 56 km with an overlying 2-4 km sedimentary thickness of shear wave velocity of 2.55-2.75 km s -1. The shear wave velocity in the upper 10 km of crust is 3.5-3.7 km s -1 below the sedimentary layer. The inferred high shear velocity for the lower crust beneath these regions suggests an oceanic affinity and they are different from the Indian shield structure. The lower crust must have an oceanic origin as derived from the reminiscent of a certain oceanic lithosphere. The available data do not permit us to estimate the upper mantle structure precisely; however, it shows a higher upper mantle shear velocity of 5.1-5.3 km s -1. This may be indicative of active tectonism beneath these regions in the uppermost mantle. The Moho boundary is not sharply defined here. The increase in crustal thickness may be due to the collision of the Indian and Eurasian plates in the north and subduction of the Indian plate beneath the Burmese Arc in the east.
Journal of Geophysics and Engineering, 2008
... through-wall imaging R Chandra, Abhay N Gaikwad, Dharmendra Singh and MJ Nigam Electronics an... more ... through-wall imaging R Chandra, Abhay N Gaikwad, Dharmendra Singh and MJ Nigam Electronics and Computer Engineering Department, Indian Institute of Technology Roorkee, Roorkee-247 667, India E-mail: dharmendrasing@yahoo.com ...
Progress in Electromagnetics Research B, 2009
Page 1. Progress In Electromagnetics Research B, Vol. 17, 2948, 2009 ANALYSIS OF CLUTTER REDUCTI... more Page 1. Progress In Electromagnetics Research B, Vol. 17, 2948, 2009 ANALYSIS OF CLUTTER REDUCTION TECHNIQUES FOR THROUGH WALL IMAGING IN UWB RANGE PK Verma, AN Gaikwad, D. Singh, and MJ Nigam ...
In through wall imaging (TWI), detection is possible due to dielectric contrasts between target a... more In through wall imaging (TWI), detection is possible due to dielectric contrasts between target and room environment. Complexity increases if room consists of furniture's and other objects beside desired target. Further detection of desired target becomes complex with the presence of window in back wall of room. Thus in this paper, effect of presence of window in back wall of room is investigated on detection and imaging. A detection technique is proposed in which signal processing technique is applied to extract the target information from clutter signal. A back projection imaging technique is applied to image the target. For this purpose, indigenously a TWI system based on step frequency continuous wave (SFCW) principle is developed in ultra wide band (UWB) range of frequency (i.e., 3.95 GHz to 5.85 GHz), plywood considered as wall and metallic plate is considered as target behind the plywood wall. The results are quite encouraging.
This work proposes a particular approach to assess information about soil degradation from NOAA/A... more This work proposes a particular approach to assess information about soil degradation from NOAA/AVHRR data. As erosive processes change physical and chemical properties of the soil, altering, consequently, the superficial color, monitoring the change in color over time can help to identify and analyze those processes. A methodology for the determination of soil color from NOAA/AVHRR data was devised, based on a theoretical model that establishes the relationship among the soil color, described in the Munsell Color System, vegetation indices, surface temperature and emissivity. The test area of the methodology was the Upper Taquari Basin, in the central region of Brazil, where the lack of land use planning and soil conservation practices have been causing severe erosion and siltation of the water bodies, increasing the spatial and temporal significance of flood events over the Brazilian Pantanal region. The tests showed that the methodology was efficient in determining soil color using the NDVI, MSAVI and PAVI vegetation indices. Best results were obtained for the hue color component. To further test the methodology, the calculated digital color models were compared with the characteristic color of soil classes in the Upper Taquari Basin.
This work proposes a particular approach to assess information about soil degradation from NOAA/A... more This work proposes a particular approach to assess information about soil degradation from NOAA/AVHRR data. As erosive processes change physical and chemical properties of the soil, altering, consequently, the superficial color, monitoring the change in color over time can help to identify and analyze those processes. A methodology for the determination of soil color from NOAA/AVHRR data was devised, based on a theoretical model that establishes the relationship among the soil color, described in the Munsell color system, vegetation indices, surface temperature and emissivity. The test area of the methodology was the Upper Taquari Basin, in the central region of Brazil, where the lack of land use planning and soil conservation practices have been causing severe erosion and siltation of the water bodies, increasing the spatial and temporal significance of flood events over the Brazilian Pantanal region. The tests showed that the methodology was efficient in determining soil color using the NDVI, MSAVI and PAVI vegetation indices. Best results were obtained for the hue color component. To further test the methodology, the calculated digital color models were compared with the characteristic color of soil classes of that region.
Tectonophysics, 1994
Fundamental-mode surface wave generated by twelve earthquakes, which occurred in northeastern Ind... more Fundamental-mode surface wave generated by twelve earthquakes, which occurred in northeastern India and nearby regions and were recorded at the Shillong (SHL) and Chiengmai (CHG) seismic stations are used to determine the shear wave velocity structure beneath these regions. The Frequency Time Analysis method is used to determine the group velocities for periods ranging from 4 to 50 s for fundamental-mode Rayleigh and Love waves. A high shear wave velocity (4.2-4.7 km s -1) is estimated in the lower 30-34 km of the crust. Crustal thickness is found to vary from 36 to 56 km with an overlying 2-4 km sedimentary thickness of shear wave velocity of 2.55-2.75 km s -1. The shear wave velocity in the upper 10 km of crust is 3.5-3.7 km s -1 below the sedimentary layer. The inferred high shear velocity for the lower crust beneath these regions suggests an oceanic affinity and they are different from the Indian shield structure. The lower crust must have an oceanic origin as derived from the reminiscent of a certain oceanic lithosphere. The available data do not permit us to estimate the upper mantle structure precisely; however, it shows a higher upper mantle shear velocity of 5.1-5.3 km s -1. This may be indicative of active tectonism beneath these regions in the uppermost mantle. The Moho boundary is not sharply defined here. The increase in crustal thickness may be due to the collision of the Indian and Eurasian plates in the north and subduction of the Indian plate beneath the Burmese Arc in the east.
Journal of Geophysics and Engineering, 2008
... through-wall imaging R Chandra, Abhay N Gaikwad, Dharmendra Singh and MJ Nigam Electronics an... more ... through-wall imaging R Chandra, Abhay N Gaikwad, Dharmendra Singh and MJ Nigam Electronics and Computer Engineering Department, Indian Institute of Technology Roorkee, Roorkee-247 667, India E-mail: dharmendrasing@yahoo.com ...
Progress in Electromagnetics Research B, 2009
Page 1. Progress In Electromagnetics Research B, Vol. 17, 2948, 2009 ANALYSIS OF CLUTTER REDUCTI... more Page 1. Progress In Electromagnetics Research B, Vol. 17, 2948, 2009 ANALYSIS OF CLUTTER REDUCTION TECHNIQUES FOR THROUGH WALL IMAGING IN UWB RANGE PK Verma, AN Gaikwad, D. Singh, and MJ Nigam ...
In through wall imaging (TWI), detection is possible due to dielectric contrasts between target a... more In through wall imaging (TWI), detection is possible due to dielectric contrasts between target and room environment. Complexity increases if room consists of furniture's and other objects beside desired target. Further detection of desired target becomes complex with the presence of window in back wall of room. Thus in this paper, effect of presence of window in back wall of room is investigated on detection and imaging. A detection technique is proposed in which signal processing technique is applied to extract the target information from clutter signal. A back projection imaging technique is applied to image the target. For this purpose, indigenously a TWI system based on step frequency continuous wave (SFCW) principle is developed in ultra wide band (UWB) range of frequency (i.e., 3.95 GHz to 5.85 GHz), plywood considered as wall and metallic plate is considered as target behind the plywood wall. The results are quite encouraging.
This work proposes a particular approach to assess information about soil degradation from NOAA/A... more This work proposes a particular approach to assess information about soil degradation from NOAA/AVHRR data. As erosive processes change physical and chemical properties of the soil, altering, consequently, the superficial color, monitoring the change in color over time can help to identify and analyze those processes. A methodology for the determination of soil color from NOAA/AVHRR data was devised, based on a theoretical model that establishes the relationship among the soil color, described in the Munsell Color System, vegetation indices, surface temperature and emissivity. The test area of the methodology was the Upper Taquari Basin, in the central region of Brazil, where the lack of land use planning and soil conservation practices have been causing severe erosion and siltation of the water bodies, increasing the spatial and temporal significance of flood events over the Brazilian Pantanal region. The tests showed that the methodology was efficient in determining soil color using the NDVI, MSAVI and PAVI vegetation indices. Best results were obtained for the hue color component. To further test the methodology, the calculated digital color models were compared with the characteristic color of soil classes in the Upper Taquari Basin.
This work proposes a particular approach to assess information about soil degradation from NOAA/A... more This work proposes a particular approach to assess information about soil degradation from NOAA/AVHRR data. As erosive processes change physical and chemical properties of the soil, altering, consequently, the superficial color, monitoring the change in color over time can help to identify and analyze those processes. A methodology for the determination of soil color from NOAA/AVHRR data was devised, based on a theoretical model that establishes the relationship among the soil color, described in the Munsell color system, vegetation indices, surface temperature and emissivity. The test area of the methodology was the Upper Taquari Basin, in the central region of Brazil, where the lack of land use planning and soil conservation practices have been causing severe erosion and siltation of the water bodies, increasing the spatial and temporal significance of flood events over the Brazilian Pantanal region. The tests showed that the methodology was efficient in determining soil color using the NDVI, MSAVI and PAVI vegetation indices. Best results were obtained for the hue color component. To further test the methodology, the calculated digital color models were compared with the characteristic color of soil classes of that region.