Measuring magnetic declination with a compass, virtual globes and a global positioning system

作     者：William P.O’Brien Jr 

作者机构：Physics DepartmentSouthwestern UniversityGeorgetownTexas78626USA 

出 版 物：《International Journal of Digital Earth》 (国际数字地球学报（英文）)

年 卷 期：2009年第2卷第1期

页      面：31-43页

核心收录：

学科分类：08[工学] 0812[工学-计算机科学与技术（可授工学、理学学位）] 

主　　题：Earth observation GPS magnetic declination geophysics 

摘      要：Earth’s magnetic declination was experimentally measured at 15 sites in western USA from Alaska to Texas;each site exhibited a large linear feature identifiable in virtual globe imagery(NASA’s World Wind or Google Earth).The difference between the geographic bearing of the linear feature measured directly on a virtual globe image and the magnetic bearing of the same linear feature measured on the ground with a compass defines the magnetic declination d for that *** all 15 sites,d values,determined by this differencing procedure,ranged from about 208 to 58 E and fell within 18(over half within 0.58)of expected *** positioning system(GPS)data recorded at most sites and plotted on virtual globe images aided in the identification of relevant *** straightforward method for determining magnetic declination using virtual globe software and a compass provides a contemporary geospatial field/laboratory activity that dramatically elucidates and contrasts features of magnetic and geographic coordinate systems for students in various disciplines involving geomagnetism,navigation,geography or spherical polar geometry.