GNSS掩星探测大气的研究现状及进展     

JIAO Ming-lian  JIANG Ting-chen 《测绘学院学报》2008,(4)

与传统的无线电探空、雷达探测等手段相比,GNSS掩星技术为大气探测提供了一个强有力的工具,其具有无校准、全天候、精度高、垂直分辨率高、全球均匀覆盖等特点。介绍了利用GNSS掩星技术获取地球大气温、压、湿等相关参数大小的研究现状。同时,提出了GNSS掩星技术在气候研究领域的发展方向,将拓宽GNSS掩星技术在全球气候变化研究中的应用。  相似文献   

南海海区渔船无线电导航仪器选用浅见     

崔照明 《广东海洋大学学报》1991,(1)

本文分析了各种无线电导航设备的特性及其在南海海区应用的优劣,并考虑到GPS对导航领域的影响,根据南海区渔船的实际需要,提出了南海区渔船选择无线电导航仪器的意见,供各类渔船在选用无线电导航仪器时作参考。  相似文献   

雾中航行     

车辉 《广东海洋大学学报》1990,(1)

本文主要介绍我国南海海区雾的生消特点,航海工作者在南海海区雾航的经验体会,如何保证雾中航行的安全,如何正确理解国际海上避碰规则中几个关键的问题。  相似文献   

Improvement of MEMS-IMU/GPS performance using fuzzy modeling     

W. Abdel-Hamid  T. Abdelazim  N. El-Sheimy  G. Lachapelle 《GPS Solutions》2006,10(1):1-11

Performance improvement of integrated Inertial Measurement Units (IMU) utilizing micro-electro-mechanical-sensors (MEMS) and GPS is described in this paper. An offline pre-defined Fuzzy model is employed to improve the system performance. The Fuzzy model is used to predict the position and velocity errors, which are the inputs to a Kalman Filter (KF) during GPS signal outages. The proposed model has been verified on real MEMS inertial data collected in a land vehicle test. A number of 30-s GPS outages were simulated during the data processing at different times and under different vehicle dynamics. Performance of the suggested Fuzzy model was compared to that of the traditional KF particularly during the simulated GPS outages. The test results indicate that the proposed Fuzzy model can efficiently compensate for GPS updates during short outages.  相似文献   

OZIEXPLORER软件结合GPS手持机在野外断裂调查中的应用     

郑韶鹏  付萍  姚道平  张永固 《华南地震》2006,26(4):26-33

野外断裂地震地质调查是活断层探测的重要手段之一,在参加野外断裂地震地质调查的过程中,经过探索与实践,利用笔记本电脑、OZIEXPLORER软件及GPS手持机,形成了一整套包括室内展图、路线设计、野外导航、野外数字化定点、野外航迹保存的工作流程,并对各种地图、卫星照片、航片的校准问题进行了探讨。  相似文献   

COMPUTATION OF RETURN FLOWS DUE TO NAVIGATION TRAFFICS IN RESTRICTED WATERWAYS     

B. S. MAZUMDER S. K. DAS S. N. DAS 《国际泥沙研究》2006,21(4):249-260

1 INTRODUCTION Movement of navigation traffic in restricted waterway can generate various hydrodynamic phenomena including return flow (RF), surge wave, drawdown and sediment re-suspension which are absent in open water conditions (Schofield and Martin, 1…  相似文献   

GPS satellite and receiver instrumental biases estimation using least squares method for accurate ionosphere modelling   总被引：1，自引：0，他引：1  

G. Sasibhushana Rao 《Journal of Earth System Science》2007,116(5):407-411

The positional accuracy of the Global Positioning System (GPS) is limited due to several error sources. The major error is ionosphere. By augmenting the GPS, the Category I (CAT I) Precision Approach (PA) requirements can be achieved. The Space-Based Augmentation System (SBAS) in India is known as GPS Aided Geo Augmented Navigation (GAGAN). One of the prominent errors in GAGAN that limits the positional accuracy is instrumental biases. Calibration of these biases is particularly important in achieving the CAT I PA landings. In this paper, a new algorithm is proposed to estimate the instrumental biases by modelling the TEC using 4th order polynomial. The algorithm uses values corresponding to a single station for one month period and the results confirm the validity of the algorithm. The experimental results indicate that the estimation precision of the satellite-plus-receiver instrumental bias is of the order of ±0.17 nsec. The observed mean bias error is of the order −3.638 nsec and −4.71 nsec for satellite 1 and 31 respectively. It is found that results are consistent over the period.  相似文献   

GPS导航战策略分析     

刘志春  苏震 《全球定位系统》2007,32(4):9-13

针对“导航战”的发展，分析了当前GPS系统的主要干扰技术与抗干扰技术，提出了研究分析GPS对抗技术的一些思路。  相似文献   

GPS车载导航电子地图制作系统的设计与实现     

华亮春段佳  熊学新 《东北测绘》2007,30(6):126-128

对GPS车载导航电子地图制作系统开发进行了深入研究，详细介绍了实现原理、系统结构、功能设计、技术难点及解决方法等关键技术。  相似文献   

SEDIMENT MODEL EXPERIMENT IN JINGHONG HYDROPOWER PROJECT AREA     

TAN Guangming  Pro.  Doc. Wuhan University of Hydraulic  electric Engineering  Wuhan  China ZHANG Xiaofeng Pro.  Doc. Wuhan University of Hydraulic  electric Engineering  Wuhan  China DUAN Wenzhong Pro. Wuhan University of Hyd 《国际泥沙研究》1997,(3)

I.BRIEFINTRODUCTIONInthechainofhydroelectricpowerstationsalongthemiddleandlowerreachesofLancangiiangforer,Jinghongpowerstationisthe6thonewiththemultipleeconomicbenefitofelectricalgenerationandnavigation.Thepowerstationconsistsof3x300MWunitsandeachturbinehasamaximumintakingflowof390m'/s.Arrangedfromtherighttoleflbankofthedamisashipelex,ator.ti7hichisaccessibleto300tonboats,thespillwa}'damsectionandthepowerhouse.Ontheright,middleandleftsideofthepotverhouserespectively.therearethreebotto…  相似文献