To validate the feasibility of gravity gradient measurements using the ZL11-4C gravimeter mounted on the FC-30 unmanned aerial vehicle (UAV) platform, this study conducted vertical take-off and landing flight experiments in Xiangyang and Wuhan. During the 0–25 m and 0–50 m hovering tests in Xiangyang, a decreasing trend in the gravity gradient with height was observed, with measured values of 2983.58 E and 2938.18 E, respectively. This demonstrates a clear linear declining trend consistent with theoretical expectations. In Wuhan, the 25–100 m hovering test yielded an average gradient value of 3079.09 E. Comparing the experimental results from Xiangyang with the theoretical gradient values from the EGM2008 model revealed that the experimental results confirm the physical principle that gravity gradients decrease with height and demonstrate the system's capability to detect subtle variations. The measurements in Wuhan showed high consistency with the model values, further verifying the reliability of the system. The differences in the experimental results from the two sites primarily reflect regional gravity field characteristics, indicating that the system can accurately measuring gradient values and sensitively detect regional gravity field variations. This provides important practical evidence for the engineering applications of UAV-based gravity gradient measurement technology.
Li et al. (2026) studied this question.