空中重力测量数据代表地面数据的误差分析

利用严密的向上延拓公式将地面重力数据上延至空中不同高度,而后与相应的地面重力数据比较从而得到不同高度的代表误差。通过两个不同地形区域的实际算例表明,对于地形平坦区域,在1km高度以下,5＇空中重力数据直接代表地面重力数据的误差小于1mGal,在满足测量规范要求下,空中重力数据可以不用向下延拓而直接使用。对于地形复杂区域,当空中测量高度大于1km时,空中重力数据的代表误差大于3.3mGal,因此必须考虑向下延拓的问题。

The Error Analysis of Land Gravity Data Represented by Airborne Gravimetry Data

Air gravity data can be acquired by upward continuation of land gravity data based on the rigorous integral formula.Then the representative error can be obtained through the comparison between the air gravity data and corresponding land gravity data.The actual computation results show that the representative error of 5′ air gravity data is about 1mGal in flat area under the 1km height.In this case the air gravity data can represent the land gravity data directly.For the area of complex terrain the representative error is about 3.3mGal when the surveying height is more than 1km so the downward continuation must be considered in the use of airborne gravimetry data.