Analysis of gravity anomalies over an inclined fault with quadratic density function   总被引：3，自引：0，他引：3  

D. Bhaskara Rao 《Pure and Applied Geophysics》1985,123(2):250-260

An attempt is made to interpret the gravity anomalies over an inclined fault with variable density contrast. The decrease of density contrast with depth in sedimentary rocks is approximated by a quadratic function. The anomaly equation of an inclined fault is derived with the quadratic density function. The constantsa ₀,a ₁ anda ₂ of the quadratic density function can be found from the known density-depth values. A synthetic anomaly profile of the fault model is interpreted by the non-linear optimisation technique using the Marquardt algorithm. The distances are measured from an arbitrary reference point and thus the origin of the fault model is also treated as an unknown parameter. For the assumed values of the constantsa ₀,a ₁ anda ₂, the various parameters of the fault model are found by the non-linear optimisation technique. The convergence of the method is shown by plotting the values of the objective function, lamda, and the parameters of the fault model with respect to iteration number. The two parameters inclination and origin are found to be correlated. The same program is used to interpret the gravity anomalies with different density contrasts. Finally, the use of modelling with the quadratic density function is discussed.  相似文献   

Transient electromagnetic response due to a pair of horizontal conducting sheets in a loop field     

R. Nagendra  I. B. Ramaprasada Rao  Satyanarayan Kabra 《Journal of Earth System Science》1985,94(3):269-277

The transient electromagnetic response due to a pair of horizontal conducting sheets induced by a loop field is obtained. The response characteristics in the three different regions (above the upper sheet, between the two sheets and below the lower sheet) are briefly discussed. In the first and second regions the composite response is characterised by an overburden response asymptote during early times and a target response asymptote during late times. The transition zones are characterised by shoulder-like bends. In the third region, the composite response increases in direct proportion to the induction number, eventually merging with the target response for large values of the induction number.  相似文献   

Evolution of Regional Hydrogeologic Setup of a Hard Rock Aquifer Through R-C Analog Model     

C. P. Gupta  M. Thangarajan  V.V.S. Gurunadha Rao 《Ground water》1985,23(3):331-335

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Effect of solar elevation on rice crop spectral response     

P. P. Nageswara Rao  A. S. Padmavathy 《Journal of the Indian Society of Remote Sensing》1985,13(2):13-18

In the present study the effect of solar elevation angle on the spectral response of rice crop was examined under farmer’s field conditions. The aim of the study is to see if band ratioing can reduce the effect of soiar elevation angle on rice crop spectral response. It was observed that the spectral transformations involving red and near infrared are highly useful in normalizing the effect of sun elevation when the canopy cover is complete. Contrary to this, the spectral transformation could not normalize the effect of sun elevation on the spectral response of rice crop when the canopy cover is incomplete.  相似文献   

Flotation of calcareous Mussorie phosphate ore     

D.Vaman Rao  M.K. Narayanan  U.B. Nayak  K. Ananthapadmanabhan  P. Somasundaran 《International Journal of Mineral Processing》1985,14(1):57-66

Separation of Mussorie rock phosphate (P₂O₅ = 20%) from Uttar Pradesh, India, containing pyrite, calcite and other carbonaceous impurities by flotation has been successfully attempted to upgrade the phosphate values. Based on Hallimond cell flotation results of single and synthetic mineral mixtures of calcite and apatite using oleic acid and potassium phosphate, conditions were obtained for the separation of calcite from apatite which is considered to be the most difficult step in the beneficiation of calcareous phosphates. Further studies using 250 g of the mineral (?60 +150 and ?150 mesh fractions, deslimed) in laboratory size Fagergren subaeration machine employed a stagewise flotation viz. carbonaceous materials using terpineol, pyrite using potassium-ethyl xanthate and calcite using oleic acid respectively. Separation was, however, found to be unsatisfactory in the absence of a depressant.Among starch, hydrofluosilicic acid and dipotassium hydrogen phosphate, which were tried as depressants for apatite in the final flotation stage, dipotassium hydrogen phosphate proved to be superior to others. However, the tests with the above fractions did not yield the required grade. This was possibly due to insufficient liberation of the phosphate mineral from the ore body and different experimental conditions due to scale up operations. Experiments conducted using ?200 mesh deslimed fractions has yielded an acceptable grade of 27.6% P₂O₅ with a recovery of about 60%. The results have been explained in terms of the specific adsorption characteristics of phosphate ions on apatite and the liberation size of the mineral.  相似文献   

Stratigraphic and structural development of the Precambrian Cuddapah basin,S.E. India   总被引：1，自引：0，他引：1  

A.M.J. Meijerink  D.P. Rao  J. Rupke 《Precambrian Research》1984,26(1):57-104

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A comparative study of different dielectric models—computation of representative dielectric profiles of black soils     

K. S. Rao  Girish Chandra  C. Suresh Raju 《Journal of the Indian Society of Remote Sensing》1987,15(2):53-63

The dielectric property of the soil is an important parameter for microwave remote sensing. Therefore an attempt is made to study and compare the models for the dielectric constant of moist soils by considering three soil types namely Haldi series (sandy loam), Hathiapathar series (silt loam) and Jambria series (clay) and at frequencies 1.4, 4.0 and 18.0 GHz. The semiempirical models of Wang et al. (1980) and Dobson et al (1985) predict more or les same results in the domain of their applicability. However, at lower frequencies below 1.0 GHz, the imaginary part of dielectric constant shows a decreasing trend with decreasing frequency for Wang et al (1980) model whereas it shows reverse trend for Dobson et al (1985) model. The soil texture and frequency dependence of dielectric constant have been investigated for Indian soils. Some of the representative dielectric profiles of black soils of Pune have been computed using semiempirical model of Dobson et al (1985) which are useful for the development of multifrequency models for the study of soil moisture.  相似文献   

Landsat mss data as base for mapping coastal soils     

B. R. M. Rao  D. C. Joshi  R. S. Dwivedi  Shyam Sunder 《Journal of the Indian Society of Remote Sensing》1986,14(1):55-60

A Soil map at 1:250,000 scale was prepared for a part of Prakasam District (Andhra Pradesh) along the east coast using Landsat MSS data through monoscopic visual interpretation in conjunctionwith collateral information and limited field check. In general, a fair amount of correlation among physiography, image elements and soils was found. Anomalies with respect to the above correlation wherever noticed are also discussed.  相似文献   

Georeference correction on landsat imagery     

T. Ch. Malleswara Rao  K. Narasimha Rao  K. V. K. Mohana Rao 《Journal of the Indian Society of Remote Sensing》1986,14(1):67-76

This paper discusses the geometric anomalies present in bulk images which are being generated on NRSA Data Processing System (DPS). A georeference correction algorithm has been presented to correct geometric scale anomalies in a systematic manner. An approach to generalize and integrate georeference correction algorithm with existing bulk correction program has been realised without crippling the speed of DPS film product generation Software. Limitations and accuracy of the algorithm are discussed.  相似文献   

Application of remote sensing for vegetation mapping — A case study along the northern coastal districts of andhra pradesh     

S. Sudnakar  P. H. V. Vasudeva Rao  Y. V. N. Krishna Murthy  R. V. Rama Rao 《Journal of the Indian Society of Remote Sensing》1986,14(2):1-8

The study deals with the application of Remote Sensing for delineating various vegetation types along the three coastal districts of Andhra Pradesh. The satellite imagery of the region is divided into three types depending upon tone and texture. Each type is correlated with the ground truth. The species composition has been given and discussed.  相似文献