摘要
航空重力测量数据主要含有两类扰动加速度,一是可用解析式表示的有规则影响,如厄特弗斯改正,另一类是与载体非规则运动有关的非规则影响,主要指垂直扰动加速度。通常有规则影响能精确求出,困难在于精确确定非规则的垂直加速度。目前常用GPS和数字滤波技术相结合来确定垂直加速度。本文概述了这种方法的基本原理,讨论了航空重力测量中有限冲激响应(FIR)低通滤波器设计参数的确定,并设计了实用的FIR低通滤波器,实测数据计算结果表明,利用该滤波器确定垂直加速度的精度为±1×10-5～2×10-5m/s2。
There are two kinds of disturbing accelerations in the airborne gravity data: one is the regular effect,e.g. Etvos correction and the other is the irregular effect,e.g. vertical disturbing acceleration. Usually, the former ones can be easy determined by a mathematical model, while the later ones are difficult to be obtained by analytic method. In principle, the vertical acceleration can be derived from the GPS position and velocity results by differentiation, but it is still too noisy as the final correction. Thus a low-pass filter process is necessary to smooth the GPS derived accelerations. The general method to determine the parameters for the design of the Finite Impulse Response (FIR) low-pass filter in the airborne gravimetry is discussed first in this paper, and then one FIR low-pass filter suit for our case is designed. The results from real data indicate that the accuracy of the vertical acceleration can be reached ±1×10^(-5)～2×10^(-5) m/s^2 using the above-mentioned filter.
出处
《测绘学报》
EI
CSCD
北大核心
2004年第2期110-115,共6页
Acta Geodaetica et Cartographica Sinica
