Magnetic survey mission in South China Sea by CW-15

According to the Chinese Society for Oceanography official news on Mar. 26th, 2020. The successful “Offshore VTOL Fixed-Wing UAV Aeromagnetic Survey System” sea trials project, led by professor Liu Qingsong from the department of Marine Science and Engineering of Southern University of Science and Technology, was selected as one of the “China's Top 10 Marine Science and Technology Advances in 2019”.

In early November 2019, a team led by professor Liu Qingsong boarded an oceanographic research vessel, and conducted maritime aeromagnetic survey test in the Pearl river estuary in the north of South China Sea.

This team was made up of top R&D talents from Southern University of Science and Technology, GTK (Shenzhen) Technology Co., LTD., and Chengdu JOUAV DAPENG Tech Co., Ltd. Committed to solve the worldwide scientific and technical problem of efficient high-resolution ocean exploration.

Covering 70% of the earth's surface, the ocean is the most active place in the world for substance, energy and biology circulation, which is closely related to human development. The ocean, however, also obscures the detailed topographical and tectonic fluctuations of the seafloor. The oceanic crust is rich in magnetic minerals. It is an effective geophysical method to study the seabed structure and the distribution of mineral resources to survey the magnetic field over the ocean.

The traditional maritime magnetic survey includes satellite magnetic survey and vessel towed magnetic survey. The former method can only get data with low resolution, and the latter way is of ultra-low efficiency. Therefore, how to efficiently carry out ocean exploration and obtain high-resolution data of seabed magnetic field anomalies is a frontier problem for today’s marine science.

In recent years, the "space – sky – sea - submarine" stereo detection has become a mainstream development trend for today’s marine science survey technology. And among that, the "Sea - Sky" joint survey which aims at improving the efficiency of investigation and the quality of results is an indispensable step.

During this offshore UAV aeromagnetic survey experimental mission, JOUAV CW-15 VTOL fixed-wing UAV has successfully carried out all of planned test subjects, such as fixed-point vertical takeoff and landing, aeromagnetic compensation test, aeromagnetic detection, mobile-platform vertical takeoff and landing, as well as the system linkage test of "Sea - Sky" joint magnetic survey, etc.

“Through relevant reports from the field of marine geosciences, this is the very first test with VTOL fixed-wing UAV aeromagnetic system”, said the project manager.

“This time we utilized the “JOUAV CW-15 shipborne solution” which can realize the mobile-platform vertical takeoff and landing function. Compared to conventional land-based version of CW-15, we added our innovative UAS positioning and orientation technology, and adjusted our autopilot system and ground control system to adapt this technology.”

According to the project manager, based on JOUAV’s years of maritime UAV application experience, this aeromagnetic survey test project achieved steady and reliable flight on the ship, demonstrated JOUAV’s sophisticated UAV technology.

JOUAV CW-15 VTOL fixed-wing UAV aeromagnetic survey system carries Vector Fluxgate Magnetometer and Atomic Rubidium Magnetometer as payload sensor. Both of the magnetometers are very compactly designed, total system weight is less than 1 kg. And the miniature rubidium optical pump magnetometer can acquire excellent data with high sensitivity and resolution. During this test project, CW-15 was cruised at 75 km/h, which is of over 4 times efficiency than using vessel.

The project manager also said that they have achieved quantum leap from zero in the "Sea-Sky" joint magnetic survey field, and grasped core technology of synchronous operation between UAV aeromagnetic survey on mobile-platform and vessel towed magnetic survey.

The data acquired by "Sea-Sky" joint magnetic survey is similar to that of traditional magnetic survey, but with more details, higher data density and can generate more types of results data. This operation mode will play a positive role in the future marine scientific research, marine resource survey and other fields.

The total filed map generate from 7 UAV surveying lines (Magnetic disturbance of the ship has been eliminated)

The measured magnetic field anomaly is obvious when UAV fly over the research vessel at 100 m AGL, this is valuable to detect submarine magnetic objects.

As the “China's Top 10 Marine Science and Technology Advances in 2,019” wining words  said: This is China’s first successful offshore VTOL Fixed-Wing UAV aeromagnetic survey system; it broke through the limitation of takeoff and landing on mobile vessel platform, overcame the magnetic disturbance of surveying ship, and realized the integrated data acquisition of multiple magnetometer systems.

Compared to traditional shipborne magnetic survey, JOUAV CW-15 offshore aeromagnetic survey system improves the operating efficiency by magnitude. This will systematically upgrade maritime magnetic survey mode, and vigorously promote major scientific studies like the mid-ocean ridge structure, marine lithosphere evolution, etc.

In addition, this system is also suitable for seabed mineral resources exploration in large scale, and will make contributions to the development of world's marine industry.