Is Newton's iteration faster than simple iteration for transformation between geocentric and geodetic coordinates?   总被引：2，自引：0，他引：2  

Piotr Laskowski 《Journal of Geodesy》1991,65(1):14-17

Summary Two iterative algorithms for transformation from geocentric to geodetic coordinates are compared for numerical efficiency: the well known Bowring's algorithm of 1976, which employs the method of simple iteration, and the recent (1989) algorithm by Borkowski, which employs the Newton-Raphson method. The results of numerical tests suggest that the simple iteration method implemented in Bowring's algorithm executes approximately 30% faster than the Newton-Raphson method implemented in Borkowski's algorithm. Only two iterations of each algorithm are considered. Two iterations are sufficient to produce coordinates accurate to the comparable level of 1E-9 m, which exceeds the requirements of any practical application. Therefore, in the class of iterative methods, the classical Bowring's algorithm should be the method of choice.  相似文献   

Chlorinated hydrocarbons in fish-eating birds wintering in the Gdańsk Bay, 1981–82 and 1982–83     

Jerzy Falandysz  Piotr Szefer 《Marine pollution bulletin》1984,15(8):298-301

Seventy-four samples of adipose fat of 10 species of fisheating birds commonly wintering in Gdańsk Bay and one of little auk, a rare species in this area, have been analysed for residues of HCB, ΣBHC, ΣDDT and PCBs. Auks (guillemot, black guillemot and razorbill), which probably stay a whole year in the Baltic area, contained in their fat twice the level of PCBs as mergansers, and 5–6 times as much as in divers and grebes—birds which stay in the sea mainly after the breeding season. ΣDDT levels were somewhat higher but comparable in auks and grebes, and lower in mergansers and divers. ΣBHC and HCB levels were 3–4 times and 5–10 times higher, respectively, in auks than in birds from other families studied. When comparing residue levels found in adipose fat of birds taken during the wintering seasons of 1981–1982 and 1982–1983 with those taken in 1975–1976 or 1980–1981, an initially rapid, but in recent years a rather slow decline in ΣDDT level is detectable for grebes, mergansers and divers, and in the case of PCBs the residue levels fell slightly. In auks, the ΣDDT residue level fell by half, but remains rather stable in recent years, while there are only minor fluctuations in the residue level of PCBs.  相似文献   

Chlorinated hydrocarbons in fish-eating birds wintering in the Gdańsk Bay,Baltic Sea, 1980–1981     

Jerzy Falandysz  Piotr Szefer 《Marine pollution bulletin》1982,13(4):132-135

Further samples of the chlorinated hydrocarbon content in adipose tissue of fish-eating birds wintering in the South Baltic show high concentrations of PCB compared with ΣDDT, HCB, alpha- and gamma-BHC. The great crested grebe presently examined had approximately four times higher PCB/ΣDDT ratios than specimens taken during 1975–1976.  相似文献   

Albian and Cenomanian planktic Foraminiferida from the Trawne Beds (Pieniny Klippen Belt,Polish Carpathians)     

M.A. Gasiński 《Cretaceous Research》1983,4(3):221-249

Eighteen Albian and Cenomanian planktic Foraminiferida from the Pieniny Klippen Belt of Poland are discussed. A local biostratigraphic zonation (six zones) is proposed and certain problems of palaeoecology are reviewed. The lithostratigraphical element is the so-called Trawne Beds, a Cretaceous flysch in the Pieniny Klippen Belt.  相似文献   

Environmental Hydraulics     

Paweł M. Rowiński 《Acta Geophysica》2007,55(1):1-2

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Use of variograms for field magnetometry analysis in Upper Silesia Industrial Region     

J. Zawadzki  P. Fabijańczyk 《Studia Geophysica et Geodaetica》2007,51(4):535-550

Measurements of topsoil magnetic susceptibility are often used for quick assessment of soil contamination of anthropogenic origin, with heavy metals or other pollutants. However, because of complicated correlations between low-field magnetic susceptibility (shortened to magnetic susceptibility) of topsoil and soil pollution, the outcome of a field magnetometry survey can not be related directly to soil pollution. For each case study, the results should be interpreted on their own taking into account not only the type of pollution but also pedogenic, biogenic and environmental factors. In practice, it is very difficult to measure and consider all these factors. Here we illustrate the merit of geostatistical methods, which are focused on the spatial variability of a phenomenon, in the interpretation of soil magnetometry results. This article presents the analysis of spatial variability of top soil layers magnetic susceptibility-within the Upper Silesia Industrial Region (USIR)-using semivariance analysis. It also explains how to adjust the sampling density of field magnetometry measurements to spatial variability of the soil pollution as well as to the spatial scale of the investigated area. For this purpose, the values of magnetic susceptibility have been measured by using various sampling densities at areas of different size located within USIR. This enabled to determine the main scales of magnetic susceptibility spatial variability of soils within USIR using semivariance. A few distinct scales of variability were found from the site scale to a more regional scale. Variability ranges of 30 km, 12 km, and 5 km refer to the large regional scale, whereas smaller ranges of few hundreds down to a few tens of meters, can be attributed to the local (site) scale. In addition, the precision of the measuring campaigns, performed within USIR with different sampling densities, was compared through the analysis of the spatial variability of the soil magnetic susceptibility signal by using ordinary kriging. jarek97@yahoo.com, piotr.fabijanczyk@is.pw.edu.pl  相似文献   

Isotope hydrological study of mean transit times in an alpine basin (Wimbachtal, Germany)     

Piotr Maloszewski  Werner Rauert  Peter Trimborn  Andreas Herrmann  Rolf Rau 《Journal of Hydrology》1992,140(1-4):343-360

Measurements of tritium and ¹⁸O concentrations in precipitation and runoff were used to provide further insight into the groundwater storage properties of the Wimbachtal Valley, a catchment area of 33.4 km², extending between 636 and 2713 m a.s.l. in the Berchtesgaden Alps. The catchment includes three aquifer types: a dominant porous aquifer; a fractured dolomite; a karstic limestone aquifer. Employing a simple hydrological model, information about mean transit times of environmental tracers is derived for the groundwater runoff component and several karst springs from the application of the exponential and dispersion flow models to the isotopic input and output data. The mean transit times calculated from a dispersion model with transit times of 4.1 years for ¹⁸O and 4.2 years for tritium, which agree well, allow calculation of total (mobile + stagnant) groundwater storage volume, which is equivalent to 6.6 m of water depth. Direct runoff appears negligible as in many other cases.  相似文献   

Wassereintrittsgeschwindigkeit zum Brunnenfilter in bezug auf die Berechnung der Filterdurchmesser     

Alfred Kepiński 《Aquatic Sciences - Research Across Boundaries》1962,24(2):272-290

Ohne Zusammenfassung  相似文献   

Origin of magnetic minerals and natural remanent magnetization of basaltic rocks from Lower Silesia,Poland     

J. Kruczyk  M. Kądziałko-Hofmokl  M. Jeleńska 《Pure and Applied Geophysics》1973,110(1):2031-2040

Summary Two groups of basaltic rocks with normal and reversed NRM were examined. It was found that in both groups the primary NRM, synchronous with the period of rock formation, is preserved. Relations of the primary NRM to the origin and the degree of oxidation of magnetic minerals were considered in detail.  相似文献   

Book reviews     

A. M. O'Connor  Fouad Ibrahim  W. F. Schmidt-Eisenlohr  Olof Nordström  Gunnar Alexandersson  Lutz Holzner  L. A. Kosiński 《GeoJournal》1978,2(5):492-494

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