摘要
重力梯度张量是重力位二阶导,相比重力异常能够更好反映局部区域的细节特征。因此重力梯度导航理论上能为惯性导航提供更好的辅助。重力梯度导航的关键技术之一是背景基准图的构建,推导了扰动重力梯度张量与扰动位在局部指北坐标系中的关系式,并基于EGM2008地球重力场模型构建了一块范围的海域扰动重力梯度张量基准图。为了快速构建基准图,选取了合适的勒让德函数,并将每一个梯度张量的计算式改变求和顺序来提高同一纬度圈上的计算点的计算速度。最后利用梯度张量对角线上三元素满足拉普拉斯约束条件的原理验证了所得基准图的正确性。
As the second derivative of gravity potential,gravity gradient tensor can better reflect the characteristics of the details of the local area compared with the gravity anomaly.So gravity gradient navigation can provide better auxiliary for inertial navigation. Background reference image is one of the key technology of gravity gradient navigation.This paper deduces the relation between disturbing gravity gradient tensor and disturbing gravity potential in local north-oriented reference frame and builds a 4° x6° range marine disturbing gravity gradient reference image based on EGM2008 earth gravity field model.In order to quickly build the reference image, the paper selects the appropriate Legendre function and changes the sum order of the gradient tensor calculation formula to improve the computing speed of the calculated point on the same latitude circle.Finally, the paper validates the correctness of the reference image by using the principle that gradient tensor on the diagonal elements meet the Laplace constraints.
出处
《海洋测绘》
CSCD
2017年第1期17-21,共5页
Hydrographic Surveying and Charting
基金
国家自然科学基金(41274029
41674082
41504018)
关键词
重力梯度导航
缔合勒让德函数
地球重力场模型
扰动重力梯度
基准图
gravity gradient navigation
associated Legendre function
earth gravity field model
disturbing gravity gradient
reference image
