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Turatto M Suzuki T Mazzali PA Benetti S Cappellaro E Danziger IJ Nomoto K Nakamura T Young TR Patat F 《The Astrophysical journal》2000,534(1):L57-L61
The extraordinary SN 1997cy associated with GRB 970514 has been observed photometrically and spectroscopically for nearly 2 yr. At the time of discovery, SN 1997cy was the brightest supernova (SN) ever observed (MV相似文献
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Abascal AJ Castanedo S Medina R Losada IJ Alvarez-Fanjul E 《Marine pollution bulletin》2009,58(2):238-248
In this work, the benefits of high-frequency (HF) radar currents for oil spill modeling and trajectory analysis of floating objects are analyzed. The HF radar performance is evaluated by means of comparison between a drifter buoy trajectory and the one simulated using a Lagrangian trajectory model. A methodology to optimize the transport model performance and to calculate the search area of the predicted positions is proposed. This method is applied to data collected during the Galicia HF Radar Experience. This experiment was carried out to explore the capabilities of this technology for operational monitoring along the Spanish coast. Two long-range HF radar stations were installed and operated between November 2005 and February 2006 on the Galician coast. In addition, a drifter buoy was released inside the coverage area of the radar. The HF radar currents, as well as numerical wind data were used to simulate the buoy trajectory using the TESEO oil spill transport model. In order to evaluate the contribution of HF radar currents to trajectory analysis, two simulation alternatives were carried out. In the first one, wind data were used to simulate the motion of the buoy. In the second alternative, surface currents from the HF radar were also taken into account. For each alternative, the model was calibrated by means of the global optimization algorithm SCEM-UA (Shuffled Complex Evolution Metropolis) in order to obtain the probability density function of the model parameters. The buoy trajectory was computed for 24 h intervals using a Monte Carlo approach based on the results provided in the calibration process. A bivariate kernel estimator was applied to determine the 95% confidence areas. The analysis performed showed that simulated trajectories integrating HF radar currents are more accurate than those obtained considering only wind numerical data. After a 24 h period, the error in the final simulated position improves using HF radar currents. Averaging the information from all the simulated daily periods, the mean search and rescue area calculated using HF radar currents, is reduced by approximately a 62% in comparison with the search area calculated without these data. These results show the positive contribution of HF radar currents for trajectory analysis, and demonstrate that these data combined with atmospheric forecast models, are of value for trajectory analysis of oil spills or floating objects. 相似文献
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当今，摄影测量学已进入了数字化软拷贝摄影测量时代。这一进步从根本上改变了该领域内的仪器使用，生产过程，从业人员和用户的关系及生成的产品。所有摄影测量过程和操作都可在一个具有强大处理器，屏幕立体观察器，高存储设备和级软件的数字摄影量工作站上实现。 相似文献
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地理信息系统中的可视化与地图接口 总被引：5，自引：0，他引：5
一、导言利用屏幕上的地图,或通过生成硬拷贝地图,可以在一个计算缺辅助信息系统中实现地理信息的可视化。无论是屏幕地图还是硬拷贝地图,其质量均取决于所使用的设备。用高质量的绘图仪生产的最好的输出品可与印刷图媲美,而廉价的绘图仪也能生产相当有用的拷贝以供急用。屏幕地图的色彩变化可以从黑白剑16256种颜色,甚至达到百万种。地理数据的可视化可以是传统的二维地图,也可以是地理数据库的用户接口,还可以是动画或三维模型,GIS的可视化既使用（X,Y,Z）数据,也使用图像甚至录像。GIS的可视化正迅速向虚拟现实发展,这是… 相似文献