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141.
在讨论测点高程平移法区域重力地改的精度问题基础上,提出了系统差概念,并推荐一种新的计算方法,即把测点高程平移法和节点高程插值法有机地结合起来实现地改,通过理论模型和实例计算,表明该方法计算精度优于节点高程插值法和测点高程平移法。 相似文献
142.
本文在分析自动脉冲数字测相基本原理的基础之上,推出了不仅与测距频率有关,而且还与填充脉冲频率及低频测相频率有关的新的频率改正公式,并给出新的频率改正公式与传统频率改正公式之间等同的条件,即有锁相环路(或频率跟踪电路)的正常工作来保证。 相似文献
143.
144.
过去一直认为稳定氯同位素比值(~(37)Cl/~(35)Cl)几乎不变。80年代以来利用高精度质谱法成功地发现了自然界氯同位素分馏作用。单纯的溶解和对流迁移作用不能引起同位素组分变化,而扩散作用、离子渗透作用和对流混合作用却可导致同位素分馏。各地不同深度海水的氯同位素成分极为一致,故以标准平均海水氯(SMOC)作为对比标准。得克萨斯—路易斯安那海湾油田水的δ~(37)Cl大致为+0.5‰~-1.25‰,且与氯浓度大致呈正相关。热液成矿系统中,氯同位素可作为研究矿床成因的示踪剂,如美国田纳西州密西西比河谷型矿床(MVD)的δ~(37)Cl在+0.2‰~-1.1‰之间,几个斑岩铜矿床(PVD)的早期脉岩与晚期脉岩中不同δ~(37)Cl的存在,都表明在成矿过程中有不同氯源的参与。 相似文献
145.
豫西南矽线石物相分析方法研究 总被引:2,自引:2,他引:2
以豫西南地区4个矿区的矿物组合为依据,建立了铝量法测定矽线石含量的物相分析方法。对比了不同方法制备的矽线石及其不同存在条件下溶解率的差异,确定了接近矿区实际的、准确合理的分析结果校正办法。 相似文献
146.
Estimation of abl Parameters Using the Vertical Velocity Measurements of an Acoustic Sounder 总被引:2,自引:0,他引:2
J. A. Kalogiros C. G. Helmis D. N. Asimakopoulos P. G. Papageorgas 《Boundary-Layer Meteorology》1999,91(3):413-449
The friction velocity, the surface heat flux and the height of the Atmospheric Boundary Layer (ABL) are important parameters. In this work, vertical velocity variance (
w
2
) and wind velocity structure parameter (C
v
2
) profiles estimated by acoustic sounder measurements are used, along with similarity relations, to estimate these parameters in the unstable Atmospheric Boundary Layer and the friction velocity in the stable one. The data were collected by two acoustic sounders with different height range and resolution under various atmospheric conditions (stability) and at two experimental sites in different terrain. The C
v
2
profiles are estimated using gate difference of the vertical velocity measurements and the assumption of local isotropy. The vertical velocity data are corrected for the significant effects of noisy measurements and sampling volume averaging on the
w
2
and C
v
2
estimations using original techniques that are presented in this work. The results of the similarity method using acoustic sounder data are compared against estimates of the corresponding atmospheric parameters obtained from direct measurements. The comparison confirms the ability of the method to provide reasonably accurate estimates of these parameters especially in the middle of the day. 相似文献
147.
57Fe-Mössbauer spectra of eleven Fe-Mg-bearing staurolite samples, synthesized at 5, 20 and 25 kbar and 680°C, ranging in composition from xFe?=1.00 to xFe?=0.15, and of two Zn-Fe-bearing staurolite samples, synthesized at 20 kbar and 700°C with xFe?=0.10 and xFe?=0.32 were collected at room temperature. The spectra reveal that about 80% of Fetot (in case of Fe-Mg-bearing staurolite) and about 70% of Fetot (in case of Fe-Zn-bearing staurolite) are located as Fe2+ at the three subsites Fe1, Fe2 and Fe3 of the tetrahedral T2-site. The refinement of the spectra results in almost identical values for the isomer shift (IS) (±1.0 mm/s) but significantly different values for the quadropole splitting (QS) for the three subsites which is in accordance with the different distortions of these sites. About 8% of Fetot (in case of Fe-Mg-bearing staurolite) and 13% of Fetot (in case of Fe-Zn-bearing staurolite) are located as Fe2+ at the octahedral M4 site, while the remainder percents of Fetot indistinguishably occur as Fe2+ at the octahedral M1 and M2 sites of the kyanite-like part of the structure. Within the whole Fe-Mg-staurolite solid solution series the Mössbauer parameters QS of the sites M4 and (M1, M2) vary systematically with composition whereas IS remains constant. There is a high negative correlation of the total Mg-content with Fe-occupation of all the Fe-bearing sites indicating a continuous substitution of Fe2+ by Mg on all these sites. Synthetic Fe-staurolites show no increasing occupation of the octahedral sites by two-valent cations with pressure, as was assumed by several authors. 相似文献
148.
ABSTRACT In this paper, we propose a method to regenerate Rational Polynomial Coefficients (RPCs) using KOMPSAT-3A imagery and to reduce the geolocation error using minimum ground control points (GCPs). To estimate the new RPCs, the physical sensor model fitted to KOMPSAT-3A imagery was utilized and virtual GCPs over the study area were created. The size of the virtual grid used was 20x20x20. To remove the sensor-related errors in physical sensor model, three different image correction models (image coordinate translation model, shift and drift model, and affine transformation model) were additionally applied. We evaluated our proposed method in two areas within Korea, one in urban (Seoul) and one in rural (Goheung) areas. The results showed that there was a significant improvement after applying the suggested approach in the two areas. The image coordinate translation model is suggested in terms of GCP requirement and expected errors estimated from the error propagation analysis using Gauss–Markov Model (GMM). 相似文献
149.
150.
遥感影像镶嵌时拼接缝的消除方法 总被引:29,自引:0,他引:29
对现有的影像并接缝消除方法的优缺点进行了分析,提出了拼接缝消除的强制改正方法,并用大量的实际图像进行了试验。结果表明:所提出的方法具有较好的拼接缝消除效果,且算法简单,易于实现,可以处理彩色和黑白等多种图像。 相似文献