航空重力测量的分辨率和精度分析

Analysis on the resolution and accuracy of airborne gravity survey

研究了航空重力测量分辨率与飞行高度的关系,表明对于300 km/h的飞行速度和2.5 km的飞行高度在山区和平地可恢复的最小波长分辨率分别为9 km和14 km,在此高度该频段重力异常的衰减率约为50%.探讨了低通滤波器截止频率对航空重力测量沿线分辨率和精度的影响,对于大同航空重力测量,滤波尺度为150,200,250 s时,沿线的半波长分辨率分别为7.5,10和12.5 km,相应的精度分别为7.5,6.2和5.5 mGal.

The relationship between the resolution of the airborne gravity and the flight height is analyzed. The result shows that gravity information with a minimum wavelength of 14 km in flat areas and 9 km in mountainous areas can be recovered by airborne gravimetry when the flight velocity is 300 km/h and the flight height above the ground is 2. 5 km. And in this case the attenuation factor of gravity anomalies is about 50%. Moreover, the effects of the cutoff- frequency of the lowpass filter on the along-track resolution and the accuracy of the airborne gravimetry are discussed. For airborne gravity survey in Datong, the spatial resolution of 5 km, 10 km, 12. 5 km and the corresponding accuracy of 7.5 reGal, 6.2 mGal, 5.5 mGal can be achieved respectively, when the scales of the lowpass filter are 150 s, 200 s and 250 s respectively.