Marine Absolute Gravity Field Surveys Based on Cold Atomic Gravimeter

Dynamic precision measurement of gravity field is of great significance to the fields of geological surveying, resource exploration, and autonomous navigation now. Current dynamic gravity measurements remain relative, thereby facing the drawbacks of accuracy calibration and measurement value drift of instruments. The operation of the absolute gravimeters in dynamic measurement could solve these problems, whereas during the measurement of absolute gravity in a dynamic environment, the interference and coupling of the dynamic environment is an important issue to research urgently. In this article, we report the new progress on our homemade marine survey system of absolute gravity, and the experimental improvements are introduced compared with the previous system. Furthermore, the experiments of marine gravity surveys campaign are carried out in the Yellow Sea of China. The crossover tracks and repeated survey lines are designed in order to evaluate the performance. The internal coincidence precision of our marine survey system is estimated to be 1.22 mGal, and the results are also in good agreement with the reference data measured by the relative gravimeter, and an external coincidence accuracy of 1.62 mGal is obtained. Finally, the methods of data processing are given in great detail, and the surveyed results are compared with satellite gravity data and the data from the shipborne relative gravimeter. Our results may be helpful for the development of marine absolute gravimeters and the actual shipborne surveys of absolute gravity.