Abstract: In response to the challenges of complex terrain and dynamic environments in deep-sea marine exploration, a split marine towed magnetic survey system architecture is proposed and the JPM-HT2 magnetometer is developed. This system decouples the electronic unit from the sensor, with the electronic module packaged in a lightweight aluminum box to enhance the system’s deployability. The sensor adopts an “8”-shaped coil structure to meet the omnidirectional detection requirements of marine magnetic surveys. A high-strength fiberglass tube is used to protect the sensor from complex mechanical impacts underwater. Experimental results show that the signal-to-noise ratio measured by the sensor at different attitudes can reach a maximum of 38. 2 and a minimum of 11. 6, which is 30. 4% of the maximum value. The sensitivity results of the sensor at different orientations indicate that the optimal sensitivity of the JPM-HT2 magnetometer in a 3-second measurement cycle is 0. 050 nT, and the worst is 0. 065 nT, better than the optimal sensitivity of 0. 1 nT of most commercial magnetometers. The dynamic measurement process is simulated in the ocean, and the dynamic sensitivity of the instrument at this time is 0. 19 nT. The magnetic resolution of the evaluation instrument is better than 0. 01 nT, which indicates that the instrument can conduct accurate magnetic detection in deep water complex terrain and dynamic environments.

Key words: marine magnetometer, proton magnetometer, omnidirectionality, sensitivity