利用移动控制架的CCD相机校正方法     

孙英君  崔信国  徐遵义 《测绘科学》2014,(2)

在CCD相机应用于城市规划、古建保护等领域中,为保证量测结果的精度,需要通过相机校正确定畸变差、内方位元素等参数。本文利用移动控制架提供的多层面、立体控制点,通过单片后方交会方法进行相机检校。结果表明,基于移动控制架的相机校正方法是可行的,结果精度良好。  相似文献   

单斜介质中方位NMO速度Thomsen参数反演方法研究   总被引：9，自引：0，他引：9       下载免费PDF全文

王德利  何樵登  韩立国 《地球物理学报》2006,49(1):249-255

采用启发式共轭梯度法，即随机爬山法 + 共轭梯度法，利用单斜介质中P波方位NMO速度椭圆轴向偏转角度接近于零这一特性，简化P波方位NMO速度公式，并利用多方位P波NMO速度，反演出某一初始CMP观测线与自然坐标系之间的夹角，作为进一步进行Thomsen各向异性参数反演的基础. 根据各向异性介质中方位NMO速度与Thomsen参数之间的关系，建立了利用三种波的多方位NMO速度及垂直传播速度反演单层单斜各向异性介质Thomsen各向异性参数的目标函数. 对计算的理论值添加具有一定标准差的正态分布的随机噪声，用以模拟实际观测存在的误差，通过对加噪后的数据进行多次反演的误差分析，表明了所建立的目标函数及选用的反演方法是有效可行的，而且相对稳定.  相似文献   

伽玛射线暴内光度和峰值能量关系的再研究     

尹跃  柏杨  张太荣  李明军 《天文研究与技术》2013,10(2)

使用了185个伽玛射线暴(简称伽玛暴)的5 218个时间分辨谱数据,重新研究了伽玛暴内光度和峰值能量的关系及该关系对火球模型的限制二研究结果表明:(1)不管是在伽玛暴内还是在伽玛暴间各向同性等值光度Liso和静止系中vF,谱的峰值能量E'p之间关系式Liso∝E'2p都存在;(2)不管是动能主导的内激波模型还是磁耗散主导的外激波模型都能很好地解释关系式Liso∝ E'2p及ω的值.这些结论与Liang等人的结论是一致的.  相似文献   

Onboard GRB trigger algorithms of SVOM-GRM   总被引：1，自引：0，他引：1  

Dong-Hua Zhao  Bo-Bing Wu  Li-Ming Song  Yong-Wei Dong  Stephane Schanne  Bertrand Cordier  Jiang-Tao Liu 《天文和天体物理学研究(英文版)》2013,(11):1381-1396

The Gamma-Ray Monitor （GRM） is a high energy detector onboard the future Chinese-French satellite named the Space-based multi-band astronomical Variable Object Monitor which is dedicated to studies of gamma-ray bursts （GRBs）. This paper presents an investigation of the algorithms that look for GRBs by searching for a significant increase in the photon count rate for the computer onboard GRM. The trigger threshold and trigger efficiency, which are based on a given sample of GRBs, are calculated with the algorithms. The trigger characteristics of onboard instruments GRM and ECLAIRs are also analyzed. In addition, the impact of solar flares on GRM is estimated, and a method to distinguish solar flares from GRBs is investigated.  相似文献   

Could bright γ-ray burst optical transients have been recorded historically？     

Richard G. Strom  Fu-Yuan Zhao  Cheng-Min Zhang 《天体物理学报》2012,(3):260-268

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Observations of the first light and the epoch of reionization     

Xiaohui Fan 《天体物理学报》2012,(8):865-890

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Gamma-ray bursts and their links with supernovae and cosmology     

Peter Meszairos  Neil Gehrels 《天体物理学报》2012,(8):1139-1161

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为了队伍的和谐与发展——局领导深入基层考察调研剪影     

《核地知与行》2009,(4):F0003-F0003

2009年12月9日,局党组书记、局长王福平（右二）和总工程师何观生（左一）在寻乌县委书记马玉福（左二）等领导陪同下深入到二六四大队双坑矿山考察。图为王福平在采矿坑道通过仪器观察矿石伽玛值变化情况。  相似文献   

浅谈判别雷暴方位及移动路径的方法     

原连星  李乃标  邱秀莲 《气象研究与应用》2009,30(Z1)

从六个方面浅谈地面观测中怎样判别雷暴方位及其移动路径的方法.  相似文献   

基于5分钟雷达资料降水估测模型的比较          下载免费PDF全文

LIU Yong-He  ZHANG Wan-Chang  SHAO Yue-Hong  ZHANG Jing-Ying 《大气和海洋科学快报》2009,2(6):327-332

For the Z-R relationship in radar-based rainfall estimation, the distribution of corresponding R values for a given Z value （or the corresponding Z value for a given R value） may be highly skewed. However, the traditional power-law model is physically deduced and fitted under the normal-distribution presumption of radar wave echoes associated with a rain rate value, and it may not be very appropriate. Considering this problem, the authors devised several generalized linear models with different forms and distribution presumptions to represent the Z-R relationship. Radar-reflectivity scans observed by a CINRAD/SC Doppler radar and 5-minute rainfall accumulation recorded by 10 ground gauges were used to fit these models. All data used in this study were collected during some large rainfalls of the period from 2005 to 2007. The radar and all gauges were installed in the catchment of the Yishu River, a branch of the Huaihe River in China. Three models based on normal distribution and a dBZ presumption of gamma distribution were fitted using maximum-likelihood techniques, which were resolved by genetic algorithms. Comparisons of estimated maximized likelihoods based on assumptions of gamma and normal distribution showed that all generalized linear models （GLMs） of presumed gamma distribution were better fitted than GLMs based on normal distribution. In a comparison of maximum-likelihood, the differences between these three models were small. Three error statistics were used to assess the agreement between radar estimated rainfall and gauge rainfall： relative bias （B）, root mean square error （RMSE）, and correlation coefficient （r）. The results showed that no one model was excellent in all criteria. On the whole, the GLM-based models gave smaller relative bias than the traditional power-law model. It is suggested that validations conducted in many previous works should have been made against a specific criterion but overlooked others.  相似文献