Viet Nam masters UAV-based gamma spectrometry technology

Dr. Lai Manh Giau, Head of the Geophysical Division and Principal Investigator of the project, shared further insights into the journey that led to this breakthrough.

The project “Research and Development of an Airborne Gamma Spectrometry Device Using Unmanned Aerial Vehicles (UAVs)” has drawn significant attention from experts. What motivated you and your team to pursue such a groundbreaking initiative?

This idea stemmed from a very practical challenge that Viet Nam’s geology sector has long grappled with. In the past, manned aircraft were typically used to conduct airborne gamma spectrometry surveys. While effective, this method was extremely costly, requiring major expenses for aircraft rental, pilots, and other operational costs. Moreover, given Viet Nam’s complex and rugged terrain, using manned aircraft posed numerous limitations and risks, and made it impossible to access narrow or confined areas.

We recognized the rapid advancement of unmanned aerial vehicle (UAV) technology and believed it offered the ideal solution. By integrating a gamma spectrometry device onto a UAV, we could overcome both financial and topographical barriers, significantly improving data collection for baseline geological and mineral surveys. The project was launched with the goal of researching, designing, and manufacturing a specialized, “made-in-Viet Nam” measurement system that would give the sector greater technological autonomy.

Not only an automation initiative, the project has also been highly regarded for its “made-in-Viet Nam” ingenuity - repurposing decommissioned equipment from the division to create a modern system. Could you share more about this process?

This is perhaps one of the achievements we are most proud of. Instead of spending a substantial budget to purchase brand-new equipment, we made a bold decision: to repurpose and upgrade old, decommissioned materials and devices from the Geophysical Division.

This process was far from simple. It required creativity, precision, and deep technical expertise from the entire team. We had to overcome numerous engineering challenges, from recalibrating aging sensors and redesigning the electronic circuitry to optimizing software to ensure stable and accurate operation on a UAV.

The result was the successful development of two airborne gamma spectrometry units. Remarkably, these devices not only met all requirements but even outperformed many comparable products on the global market. Mastering the technology and producing the equipment domestically helped us save significant costs while affirming the capabilities of Viet Nam’s engineers and scientists.

Could you detail the specific results of this research project?

The project has produced two main groups of outputs: physical products and documentation.

First, the physical products: two airborne gamma spectrometry units named SPECTRUM-UAV1. These devices not only meet but exceed many of the targeted specifications. Notably, the measurement recording interval can be adjusted from 1 to 60 seconds, far surpassing the initially planned criteria.

Although the SPECTRUM-UAV1 units use older crystals, they fully meet the standards required for geological and mineral surveys. Maintaining critical performance indicators, particularly accuracy, is highly significant in practice. In geological investigations, precision is key to correctly identifying mineral types and accurately delineating resource-rich areas.

The SPECTRUM-UAV1 devices can automatically record and transmit data and fly autonomously along programmed routes, optimizing the survey process. This capability is especially valuable for investigations in rugged, hard-to-access terrain, where traditional ground surveys or manned aircraft are impractical.

Second, the project produced a set of reports and draft technical procedures, which represent high-practical-value outputs. Specifically, the research results were used to develop a draft circular specifying technical standards for airborne gamma spectrometry using UAVs, as well as a draft economic and technical framework for measurement and data processing.

Having these procedures and frameworks provides a solid legal foundation for applying UAV technology in practice, helping to optimize costs and flight survey processes compared to traditional methods, particularly in regions with complex, fragmented terrain. The Council has fully evaluated these products and found them to meet all requirements and offer exceptional value.

What improvements do you think the device still needs?

The Advisory, Evaluation, and Acceptance Council of the Ministry of Agriculture and Environment has just approved the project. To finalize it, we will add flight test results for each unit and compare them with existing ground-based gamma spectrometry data, including data from the 2025 rare-earth exploration project. This will provide more concrete evidence of the device’s effectiveness.

The team will revise the reports and draft procedures, correcting editorial errors to ensure scientific accuracy and consistency. At the same time, we will develop an appropriate calibration and verification procedure tailored to the manufactured devices.

In addition to refining and clarifying the technical specifications, we will conduct further testing of the devices under various weather conditions to provide appropriate usage guidelines, such as rain resistance and impact tolerance during landing.

These suggestions are crucial for improving the quality of the final product and ensuring that the devices operate at peak efficiency when widely deployed in practice.

Thank you very much!

The project “Research and Development of an Airborne Gamma Spectrometry Device Using Unmanned Aerial Vehicles (UAVs)” is part of the program “Research on Innovation, Design, and Manufacture of Specialized Equipment for Basic Resource and Environmental Surveys and Waste Management, 2021-2025” and was conducted from 2023 to 2025. Once approved, the device is expected to be ready for practical application and production from 2026.