一种改进的SAR干涉图综合滤波算法研究

SAR干涉图作为相位信息的载体,其质量直接影响对研究区域形变状况的进一步分析,采取有效的滤波算法能抑制干涉图相位噪声,提高干涉测量精度。在获得的干涉相位图中,由于矿区开采而造成的地表沉降会体现出近环状相位条纹的特征。针对这一特点,对传统的基于梯度的滤波算法做出了改进,并结合Goldstein频域滤波和改进的梯度自适应滤波,提出了一种适用于矿区沉降形成的SAR干涉相位模式滤波方法。选取河北峰峰煤矿的PALSAR干涉相位图作为实验数据,对该滤波方法做出了详细的性能评价和对比。结果表明,采用本文提出的综合滤波方法在显著降低实验区SAR干涉图相位噪声的同时,也很好地保持了相位分辨率,使由于矿区沉降而造成的形变相位环的边缘形态更加清晰。     

Structure of the stably-stratified boundary layer during the SESAME-1979 experiment

Airplane measurements in the stable boundary layer during the SESAME-1979 experiment (southcentral Oklahoma, U.S.A.) are examined in terms of the local similarity theory. The obtained results are compared with data from the Minnesota (1973) experiment and with data collected previously on towers in Cabauw (Netherlands) and Boulder (Colorado, U.S.A.). The comparison indicates that the SESAME data are strongly influenced by the terrain features of the experimental site.On leave from: Institute of Environmental Engineering, Warsaw Technical University, 00653 Warsaw, Poland.     

Petroleum exploration models—Estimation and applications

Three statistical models of oil and gas exploration prevail in the literature: field size distribution, exploration function, and effectiveness of exploration models. They may have many functional forms and may be used for prediction and planning results of future exploration activity. A review of American and Soviet literature of exploration models is presented with special emphasis on functions suitable for countries which, like Poland, are not rich in oil and gas. Two new procedures are proposed: a method for assessing field size distribution and a method for simultaneous interval estimation of parameters of the exploration function. The methods complement existing ones as they are suited to areas that are not rich in hydrocarbons. Examples of application to exploration of two Polish petroliferous basins are given.     

Structural integrity of cracks in the head of Washington on Mount Rushmore

Summary Preliminary studies of the stability of Mt Rushmore shows a tendency for permanent crack deformation resulting from seasonal opening and closing of cracks in the structure.     

Flow of metals into the global atmosphere

Concentrations of ¹³⁷Cs, ²¹⁰Pb, ²²⁶Ra, U, V, Pb, Cd and Hg have been measured in firn and ice deposited during the past three decades in accumulation zones of glaciers and also in pre-industrial glacier ice collected in Spitsbergen, Northern Norway, Alaska, Southern Norway, Alps, Himalayas, Ruwenzori, Peruvian Andes, and at King George Island in Antarctica. Except for Hg, the geographical distribution of mean concentrations of ²²⁶Ra, U and stable heavy metals in contemporary ice is not uniform, with the lowest concentrations found in Northern Norway, Alaska and Antarctica, and the highest in continental locations at equatorial and middle latitudes. We did not find evidence of changes in rate of metal deposition during the last three decades, as compared with pre-industrial period, however, our samples of pre-industrial ice might be contaminated in part by contemporary fallout migrating from the exposed surface of old parts of glaciers into the deeper ice layers. Using the data on annual injections of ¹³⁷Cs into the global atmosphere and mean global concentrations of radionuclides and heavy metals found in contemporary ice the global annual flows of ²²⁶Ra, ²¹⁰Pb, U,V, Pb, Cd and Hg were estimated as 6.6 kCi, 485 kCi, 12kt, 4870kt, 590 kt, 180 kt and 190 kt, respectively. These estimates are 1–2 orders of magnitude higher than estimates based on primary paniculate emissions. The anthropogenic contribution is a small fraction of the flows, which are dominated by natural processes leading to enrichment of metals in airborne dust.     

Kinetic study of abstraction of ethyl xanthate ions by oxidized chalcocite surface

The results of potassium ethyl xanthate (EtXK) consumption measurements by synthetic chalcocite (Cu₂S grain-sized classes of 60–75 μm and 120–200 μm, respectively) are presented. These measurements were done in a modified circulation apparatus in an argon or oxygen atmosphere at pH=9.5. The experimental results were compared with theoretical results predicted by a mathematical model based on the assumption that the EtX^? ions were immobilized as a result of a chemical reaction (or reactions), e.g., of an ion-exchange type, taking place within the oxidation product layer (OPL), formed on the Cu₂S surface.The experimental and theoretical results are in good agreement especially for small values of Q₀ (Q₀ is the initial mass of the EtX^? in solution per mass unit of Cu₂S). In this case both the theoretical and experimental results show that the EtX^? concentration in solution decays exponentially with time.     

On similarity in the atmospheric boundary layer

A similarity theory for the atmospheric boundary layer is presented. The Monin-Obukhov similarity theory for the surface layer is a particular case of this new theory, for the case of z 0. Universal functions which are in agreement with empirical data are obtained for the stable and convective regimes.On leave from Institute of Environmental Engineering, Warsaw Technical University, 00653 Warsaw, Poland. Present address, Department of Geological and Geophysical Sciences, University of Wisconsin, Milwaukee, WI 53201 U.S.A.