Modulation of ionospheric conductivities during high-power wave propagation     

S. S. De  B. K. Sarkar  B. Ghosh  A. C. Sen  S. Bandyopadhyay  S. K. Adhikari 《Earth, Moon, and Planets》1991,53(1):1-10

Enhancement of conductivity tensor modification within the ionospheric plasma by electron density modulation through the temperature dependence of the recombination rates of different ionspecies caused due to electron temperature modulation during high-power wave propagation is studied. Variation of Hall and Pedersen conductivities of the ionosphere has been investigated in the height range between 85 km to 250 km. The generation of waves at the modulation frequency and its harmonics in the ELF, VLF bands in the process is discussed.  相似文献   

Harnessing earth observation (EO) capabilities in hydrogeology: an Indian perspective     

S. Bandyopadhyay  S. K. Srivastava  Madan K. Jha  V. S. Hegde  V. Jayaraman 《Hydrogeology Journal》2007,15(1):155-158

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Single hidden layer artificial neural network models versus multiple linear regression model in forecasting the time series of total ozone     

G. Bandyopadhyay B.Sc. in chemistry  M.Sc.  S. Chattopadhyay B.Sc. 《International Journal of Environmental Science and Technology》2007,4(1):141-149

Present paper endeavors to develop predictive artificial neural network model for forecasting the mean monthly total ozone concentration over Arosa, Switzerland. Single hidden layer neural network models with variable number of nodes have been developed and their performances have been evaluated using the method of least squares and error estimation. Their performances have been compared with multiple linear regression model. Ultimately, single-hidden-layer model with 8 hidden nodes have been identified as the best predictive model.  相似文献   

Some remarks on the universal X-ray background     

Probhas Raychaudhuri  Pratul Bandyopadhyay 《Astrophysics and Space Science》1971,13(1):185-188

It is shown that a universal steady X-ray background with the energy flux 10^–7 erg cm^–2 s^–1 sr^–1 can arise as a superposition of radiation from pulsars (neutron stars) in various galaxies when it is taken into account that supernova outburst occurs in a galaxy at the rate of 10^–2/year.  相似文献   

Predicting Wheat Grain and Biomass Yield Using Canopy Reflectance of Booting Stage   总被引：1，自引：0，他引：1  

S. Pradhan  K. K. Bandyopadhyay  R. N. Sahoo  V. K. Sehgal  R. Singh  V. K. Gupta  D. K. Joshi 《Journal of the Indian Society of Remote Sensing》2014,42(4):711-718

Field experiment was conducted in a sandy loam soil of Indian Agricultural Research Institute, New Delhi during the year 2011–13 to see the effect of irrigation, mulch and nitrogen on canopy spectral reflectance indices and their use in predicting the grain and biomass yield of wheat. The canopy reflectances were measured using a hand held ASD FieldSpec Spectroradiometer at booting stage of wheat. Four spectral reflectance indices (SRIs) viz. RNDVI (Red Normalized Difference Vegetation Index), GNDVI (Green Normalized Difference Vegetation Index), SR (Simple Ratio) and WI (Water Index) were computed using the spectral reflectance data. Out of these four indices, RNDVI, GNDVI and SR were significantly and positively related with the grain and biomass yield of wheat whereas WI was significantly and negatively related with the grain and biomass yield of wheat. Calibration with the second year data showed that among the SRIs, WI could account for respectively, 85 % and 86 % variation in grain and biomass yield of wheat with least RMSE (395 kg ha^?1 (15 %) for grain yield and 1609 kg ha^?1 (20 %) for biomass yield) and highest d index (0.95 for grain yield and 0.91 for biomass yield). Therefore it can be concluded that WI measured at booting stage can be successfully used for prediction of grain and biomass yield of wheat.  相似文献   

Training Programme on Hyperspectral Remote Sensing and Applications in Water Resources (HYPERWATER-2013)     

Sujay Bandyopadhyay  Tapas Acharya 《Journal of the Geological Society of India》2013,82(2):200-201

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Sakoli Metallogeny: An Example of Pre-Grenvillian Metal Province from Central India     

B.K. Bandyopadhyay   《Gondwana Research》2001,4(4):568-569

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Assembly of the Rodinia Supercontinent: Evidence from the Sakoli and Sausar Belts in Central India     

B.K. Bandyopadhyay  A. Chattopadhyay  A.S. Khan  A.K. Huin 《Gondwana Research》2001,4(4):569-570

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Detection of 2009 Leonid,Perseid and Geminid Meteor Showers through its effects on Transmitted VLF Signals     

S. S. De  B. K. De  Pinaki Pal  B. Bandyopadhyay  S. Barui  D. K. Haldar  Suman Paul  Minu Sanfui  Goutami Chattopadhyay 《Astrophysics and Space Science》2011,332(2):353-357

The detection of 2009 Leonid, Perseid and Geminid meteor showers over Agartala, Tripura, India (Lat: 23.0° N, Long: 91.4° E) will be reported here by using two VLF receivers tuned to subionospheric transmitted VLF signals at the frequency 16.4 kHz from Aldra Island, Norway (Lat: 66.42° N, Long: 13.13° E) and the other at 18.2 kHz from Vijayananarayanam, India (Lat: 8.4° N; Long: 77.7° E). The received signals exhibited their peak values on November 17, 2009 when ZHR (Zenithal Hourly Rate) was highest. Some typical variations which are observed in the records of amplitude during the 2009 Leonid, Perseid and Geminid meteor showers will be presented in this paper.  相似文献   

Studies on the Effects of 2009 Leonid Meteor Shower on Subionospheric Transmitted VLF Signals and Vertical Electric Potential Gradient     

S. S. De  B. Bandyopadhyay  S. Barui  Suman Paul  D. K. Haldar  D. De  B. K. De  S. Chattopadhyay  A. K. Kundu 《Earth, Moon, and Planets》2012,108(2):111-121

The effects of 2009 Leonid Meteor Shower upon the two VLF subionospheric transmitted signals and vertical electric potential gradient from the ground surface have been studied from Kolkata (Lat: 22.56°N, Long: 88.5°E) on November 17, 2009. The received signals showed their peak values when ZHR (Zenithal Hourly Rate) was highest. Some typical variations in the outcome of these measurements during the meteor showers will be presented in this paper.  相似文献