Accuracy evaluation of multi-rotor UAV gravity data

Unmanned aerial vehicle (UAV) gravity measurement is a novel measurement method that utilizes UAV platforms equipped with gravimeters to collect aerial gravity data. It is characterized by flexibility, efficiency, low cost, and high resolution. However, systematic evaluation methods for the accuracy of UAV gravity measurement data remain incomplete. To address this issue, we propose an external accord accuracy verification method that extends upward from ground-based measurement data, establishing an evaluation system for internal and external accord accuracy. Internal accord accuracy is primarily evaluated using the mean square error of repeat line discrepancies and the mean square error of crossover discrepancies, reflecting the internal accord of the system. External accord accuracy is evaluated by comparing the gravity values at flight altitude with the high-accuracy ground gravity values after upward continuation. The test results show that, with a 150-s cutoff period filtering process, the repeat-line internal accord accuracy of UAV gravity measurements can reach 0.30 mGal, and the crossover internal accord accuracy can reach 0.38 mGal. By performing upward continuation of the ground gravity measurement point data using the Poisson integral method, and comparing the results with the UAV gravity data, external accord accuracy can reach 0.39 mGal.