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841.
842.
LANDSAT-1 (ERTS-1) data of the complete scene, 1218-04320, covering an area 185 Km x 185 Km in the Godavari Valley, India was computer processed in the Computer Division of the Oil and Natural Gas Commissíon to produce an imagery of readily recognizable land forms. Comparison with the original maps supplied by NASA showed an amazing agreement in quality. Computer oriented data enhancement techniques were developed and the data was reprocessed with the help of these techniques. The resulting imagery reveal an improvement over the originals. The computer software package developed to-date comprises nine different programmes to process the LANDSAT data on the IBM 360, 370 series. 相似文献
843.
To the east of Nanchang,the capital of Kiangsi Province,there cropsout a continuous belt of Permian coal series~1 trending approximately in thedirection from N.E.to S.W.Broadly speaking,this coal belt forms a synclinal 相似文献
844.
845.
This study has been motivated by the detection of a small number of optically thin microwave bursts with maximum emission near the loop top, which is contrary to the prediction of isotropic gyrosynchrotron models. Using Nobeyama Radioheliograph (NoRH) high-spatial-resolution images at 17 and 34 GHz, we study the morphology at the radio peak of 104 flares that occurred relatively close to the limb. Using data from the Nobeyama Polarimeter we were able to determine whether the 17- and 34-GHz emissions came from optically thin or thick sources. We identified single-loop events, taking into account supplementary information from EUV and soft X-ray (SXR) images. We found optically thin emission from the top of the loop in 36% of single-loop events. In agreement with standard models, in this sample 46% and 18% of the events showed optically thin emission from the footpoints and optically thick emission from the entire loop, respectively. The derived percentage of events with gyrosynchrotron emission from isotropic populations of energetic electrons is possibly an upper limit. This point is illustrated by the analysis of an optically thin event that shows footpoint emission during the rise phase and loop-top emission during the decay phase. A model that takes into account both anisotropies in the distribution function of nonthermal electrons and time evolution can reproduce the observed transition from footpoint to loop-top morphology, if electrons with pitch-angle anisotropy are injected near one of the footpoints. 相似文献
846.
J. Klokoník J. Kostelecký C.A. Wagner P. Schwintzer Ch. Förste R. Scharroo 《Journal of Geodesy》2005,78(7-8):405-417
Since the advent of CHAMP, the first in a series of low-altitude satellites being almost continuously and precisely tracked by GPS, a new generation of long-wavelength gravitational geopotential models can be derived. The accuracy evaluation of these models depends to a large extent on the comparison with external data of comparable quality. Here, two CHAMP-derived models, EIGEN-1S and EIGEN-2, are tested with independent long-term-averaged single satellite crossover (SSC) sea heights from three altimetric satellites (ERS-1, ERS-2 and Geosat). The analyses show that long-term averages of crossover residuals still are powerful data to test CHAMP gravity field models. The new models are tested in the spatial domain with the aid of ERS-1/-2 and Geosat SSCs, and in the spectral domain with latitude-lumped coefficient (LLC) corrections derived from the SSCs. The LLC corrections allow a representation of the satellite-orbit-specific error spectra per order of the models spherical harmonic coefficients. These observed LLC corrections are compared to the LLC projections from the models variance–covariance matrix. The excessively large LLC errors at order 2 found in the case of EIGEN-2 with the ERS data are discussed. The degree-dependent scaling factors for the variance-covariance matrices of EIGEN-1S and –2, applied to obtain more realistic error estimates of the solved-for coefficients, are compatible with the results found here. 相似文献
847.
848.
Chow K'ou Tien is a large village at IIO li S. W. of Peking j at the footof the Western Hills which rise from the plain. The fossil deposit occurs in thefissure caves of the Ordovician limestone. The general geology of the regionhas been described by L. F. Yih in 1920 in the Survey memoir; the main fossili- 相似文献
849.
C R DE FREITAS 《New Zealand geographer》1994,50(1):30-32
Major changes are occurring in the global warming debate. Popular alarmist views are giving way to more balanced assessments of the situation. There is now greater emphasis on the lack of consensus among climatologists on fundamental scientific issues related to climate change. 相似文献
850.