| Summary: | Airborne gravimetry has been proved to be the primary technique to efficiently obtain middle to short wavelength signals of the Earth’s gravity field in regional geodetic applications. In particular, the LCR (LaCoste & Romberg) based scalar system (i.e., only measuring the vertical component of the gravity) is widely used or still in use for regional geoid improvements. In various aspects, many previous publications have shown positive contributions from the airborne gravity data obtained from such a system. However, the system equation used in these publications has several unnecessary or unclear approximations. By using the exact formulas and realistic data sets, the numerical analysis in this paper clearly shows that: 1) the higher order terms in the Eötvös correction neglected by Harlan (1968) are rather small (in μGal level), but are systematic mainly depending on latitude and height; 2) neglecting the roll and pitch angles can cause up to hundreds of mGal errors in the raw (unfiltered) gravity measurements if the lever-arm is not set up appropriately; 3) large (200s) smoothing windows have to be applied to reduce the lever-arm noise into sub-mGal level; 4) even under strong lever-arm setup conditions, i.e., no “horizontal offset” between the GPS antenna and the gravimeter, accurate (10 arc-minute ∼ 5 arc-minute) attitude angles from IMU (Inertial Measurement Units) are required to keep the lever-arm noise in sub-mGal level in the raw observables
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