辽河盆地东部浅海地区层位标定方法

地震反射层的地质层位是地震资料解释的基础,确定地震反射层的常用方法是利用声波测井资料,通过合成记录与反射层的标定。但声波测井的分辨率较高,地震记录的分辨率低,直接利用声波测井曲线制作合成记录,与实际地震记录进行层位标定常常不匹配。为提高层位标定的准确性,参考了多种测井曲线与岩性的对应关系,以及合成记录极性与岩性和层位的对应关系,在辽河盆地东部浅海地区实现了准确的层位划分。     

Interferometric Baseline Performance Estimations for Multistatic Synthetic Aperture Radar Configurations Derived from GRACE GPS Observations

Recent studies have demonstrated the usefulness of global positioning system (GPS) receivers for relative positioning of formation-flying satellites using dual-frequency carrier-phase observations. The accurate determination of distances or baselines between satellites flying in formation can provide significant benefits to a wide area of geodetic studies. For spaceborne radar interferometry in particular, such measurements will improve the accuracy of interferometric products such as digital elevation models (DEM) or surface deformation maps. The aim of this study is to analyze the impact of relative position errors on the interferometric baseline performance of multistatic synthetic aperture radar (SAR) satellites flying in such a formation. Based on accuracy results obtained from differential GPS (DGPS) observations between the twin gravity recovery and climate experiment (GRACE) satellites, baseline uncertainties are derived for three interferometric scenarios of a dedicated SAR mission. For cross-track interferometry in a bistatic operational mode, a mean 2D baseline error (1σ) of 1.4 mm is derived, whereas baseline estimates necessary for a monostatic acquisition mode with a 50 km along-track separation reveal a 2D uncertainty of approximately 1.7 mm. Absolute orbit solutions based on reduced dynamic orbit determination techniques using GRACE GPS code and carrier-phase data allows a repeat-pass baseline estimation with an accuracy down to 4 cm (2D 1σ). To assess the accuracy with respect to quality requirements of high-resolution DEMs, topographic height errors are derived from the estimated baseline uncertainties. Taking the monostatic pursuit flight configuration as the worst case for baseline performance, the analysis reveals that the induced low-frequency modulation (height bias) fulfills the relative vertical accuracy requirement (σ<1 m linear point-to-point error) according to the digital terrain elevation data level 3 (DTED-3) specifications for most of the baseline constellations. The use of a GPS-based reduced dynamic orbit determination technique improves the baseline performance for repeat-pass interferometry. The problem of fulfilling the DTED-3 horizontal accuracy requirements is still an issue to be investigated. DGPS can be used as an operational navigation tool for high-precision baseline estimation if a geodetic-grade dual-frequency spaceborne GPS receiver is assumed to be the primary instrument onboard the SAR satellites. The possibility of using only single-frequency receivers, however, requires further research effort.Deutsche Forschungsgemeinschaft (DFG) research fellow until Sept. 2004 at the Microwaves and Radar Institute, Deutsche Zentrum für Luft- und Raumfahrt (DLR) e.V., 82234 Weßling, Germany     

无地面控制点的星载SAR影像直接对地定位研究

针对星栽合成孔径雷达（SAR）对地面目标的定位问题，分析了在无地面控制点的情况下，利用距离-多普勒（R-D）模型和地球模型进行对地定位的理论与方法，给出了在无地面控制点（GCP）而有数字高程模型的情况下利用R-D模型进行对地定位的求解方法。用天津地区ERS-1数据进行实验，其结果与当地地形图进行比较，精度在50m以内，表明该文提出的方法是正确、可行的。     

Response spectral attenuation relationships for Singapore and the Malay Peninsula due to distant Sumatran‐fault earthquakes

As part of the effort to assess the seismic hazards of Singapore and the Malay Peninsula, representative ground motion prediction models have to be established. Seven existing attenuation relationships developed for shallow crustal earthquakes in stable continent and active tectonic regions are examined, and they are found to consistently over‐predict the ground motions of Sumatran‐fault earthquakes recently recorded in Singapore. This may be attributed to the differences in the regional crustal structures and distance ranges considered. Since the number of recorded ground motions in the region is very limited, a new set of attenuation relationships is derived based on synthetic seismograms. The uncertainties in rupture parameters, such as stress drop, focal depth, dip and rake angles, are defined according to the regional geological and tectonic settings as well as the ruptures of previous earthquakes. Ground motions are simulated for earthquakes with Mw ranging from 4.0 to 8.0, within a distance range from 174 to 1379km. Besides magnitude and distance, source‐to‐station azimuth is found to influence the amplitudes of the ground motions simulated. Thus, the azimuth is taken as an independent variable in the derived ground motion attenuation relationships. The Sumatran‐fault segments that have the potential to generate a specified level of response spectral accelerations in Singapore and Kuala Lumpur are identified based on the newly derived ground motion models. Copyright © 2003 John Wiley & Sons, Ltd.     

地震现场建筑物安全性鉴定智能辅助系统研究

本文是在对《地震现场建筑物安全鉴定》(GB18208．2—2001)国家标准进行研究和理解的基础上，对应用中出现的问题进行了分析。为了使在现场安全鉴定的工程技术人员能够较为科学、规范化地使用该标准，我们对国标中定性条款进行了量化处理，并提出了应用两层的模糊评价模型对受震房屋的震损进行鉴定的方法。最后对地震现场建筑物安全性鉴定智能辅助系统总体设计作了说明，并简要阐述了该系统的应用价值。     

Findings through the AsiaFlux network and a view toward the future

The preliminary results of long-term CO2 flux measurements at forest sites in East Asia are explained and compared with each other. The features of seasonal variation of CO2 fluxes are different among deciduous-broadleaf, evergreen-coniferous, deciduous-coniferous and tropical forests in East Asia, and the causes of difference are discussed. The integrated yearly NEP (net ecosystem production) estimated from the CO2 flux by eddy covariance method in various forests of East Asia has a notable difference in the range of 2 to 8 tC ha-1 yr-1. The main factors of this difference are the annual mean temperature and tree species. Furthermore, the remaining issues are discussed, such as the quantitative estimation of the CO2 flux by the eddy covariance method and the synthetic analysis of the carbon budget under collaborations with biological survey.     

Application of GIS in Mineral Resource Prediction of Synthetic Information

This paper introduces the fommtion mechanism and synthetic information prediction of large and superlarge deposits in Shandong Province by analyzing and studying on the GIS platform.The authors established a prospecting model of synthetic information from large and superlarge gold deposit concentration region, and the multi-source spatial database from concentration region of deposits and anomalies. On the basis of the spatial database, a target map layer, a model map layer and a predictive map layer were set up. Based on these map layers, geological variables of the model unit and predictive unit were extracted, then launched location and quantitative prediction of the gold deposit concentration region. The achievement of predicting large and superlarge deposits by the GIS platform has enabled the authors to design automation (or semi-automatic) interpretation subsystems, namely geophysics, geo-chemistry, geologic prospecting and comprehensive prognosis, and a set of the applicable GIS sofeware for mineral resmwcm prognosis of synthetic infornmtion.     

人工微生物脱氮过程中含水层堵塞问题的实验研究

微生物的生命活动往往会引起含水层堵塞,这一问题直接影响着人工微生物脱氮技术的推广和应用,为了寻求妥善的解决办法,笔者进行了大量的实验研究工作。本文就微生物堵塞问题的研究现状,堵塞机理以及含水层渗透系数随时间变化规律等予以阐述,以对今后的大面积推广提供一些参考。