Hovering over Vulcano's Grand Crater, a small propeller-driven drone does something most people would rather not do: fly near the source of poisonous, corrosive volcanic gases. German researcher Marius Schaab of the Technical University of Munich (TUM) watches as the drone positions itself against a laser sensor mounted on a tripod, then tracks a predefined path to collect measurements.

The setup is direct and clever. The sensor “transmits an invisible laser beam” through volcanic gas emissions at the crater’s edge, then the beam reflects back from the drone. Schaab describes the core principle as “sending a laser beam through some gas and then onto some reflector that measures the intensity of the driving light.” In other words, the system turns an invisible light signal into a gas concentration signal, without the sensor team putting the sensor itself in the plume.

Vulcano’s appeal to researchers is obvious. The island’s last eruption of the Grand Crater was in the late 19th century, but the volcano keeps showing intense degassing activity. Visitors can walk around the rim and watch steam and sulfur-smelling gases rise. For scientists, that ongoing activity is exactly why drones matter: the volcano is not “off.” It is continuously communicating with the atmosphere through gas.

This is also why the drone’s positioning matters. Schaab explains that using a laser lets the sensor avoid the gas plume, and that the corrosive nature of the plume would force constant recalibration if the sensor were inside it. The operational idea is simple but high-stakes in practice: the drone flies behind the plume and the ground unit is not in the plume. That means the measurement approach can focus on stability and repeatability, rather than constantly fighting corrosion and drift. The drone can move around and adjust angles for full measurements, then an algorithm calculates a map of gas concentration in the 10 or 15 minutes it takes for the drone to follow the predefined path, at distances of up to 60 meters (nearly 200 feet).

Drones have been used in monitoring volcanoes for about 15 years, but the research now pushing ahead is about upgrading gas measurement tools so they are increasingly accurate and risk-free. In parallel, another German team from the University of Mainz is using sensors carried on a drone to measure concentrations of chemical substances in the air. The objective is not just spectacle. One reason to measure gases and particles is to better understand the impact of volcanic eruptions and volcanic emissions on the atmosphere. Another is to anticipate eruptions, because the gas composition can change before an eruption occurs. That sequencing matters: if composition shifts before the main event, monitoring becomes a forecasting tool, not just a post-mortem.

The physics behind the monitoring is grounded in how Earth pressure translates into chemistry. The more pressure exerted by lava rising from inside the Earth toward the surface, the larger the amount of gas released. That links the measurements to what could happen next. TUM’s team also frames this as a milestone: it is the first time their team has tested its drone system, which can work at altitudes up to 3,000 meters, on an actual volcano.

On the Mainz side, the drone work is also detailed and safety-driven. A checklist in hand, Jonas Krajewski, a student at Johannes Gutenberg University Mainz, checks that “Tina,” the name given to the drone, is ready to fly safely. The drone, weighing 2.5 kilograms (5.5 pounds), lifts and heads toward rising gases for a predefined flight path lasting up to 40 minutes. This time it flies into fumaroles, vent areas where gases and vapor escape and where temperatures range between 100 and 140C. “Tina” is equipped with a series of sensors measuring gases, particles and halogens, elements like chlorine and bromine and others. Krajewski says the team has a “very constant output of gas,” enabling “very reliable sensor data.” Roberts, collaborating with the Mainz team, highlights a practical advantage that executives should recognize even outside volcanology: flexibility. A drone can move around more diluted parts of the plume and switch direction quickly if the plume changes angles. With a drone, researchers no longer need to carefully enter gas emissions, a dangerous activity that requires masks and other protection. Roberts adds a nuance that matters for risk planning: while there is no major risk of an imminent eruption at Vulcano, there are volcanoes where you cannot reach the summit on foot, and with drones, “you can take measurements... without putting yourself in danger.”

And the testing is not staying put. In the coming days, the next challenge for the drone is Mount Etna, a 3,000 meter-high active volcano in eastern Sicily, where a new eruption has just occurred. That is the real strategic stress test: can these measurement approaches handle a higher-profile, more dynamic environment where the next change can happen faster than a field team can move?

For leaders in tech-enabled measurement, this is a reminder that the next wave of “monitoring” is not just about collecting data, it is about designing systems that work near hazards without adding operational risk. If drone-based gas mapping can deliver fast concentration maps, stable laser-reflector sensing, and reliable sensor outputs across changing plume angles, then boards and operators should expect regulators, insurers, and research funders to increasingly ask for the same qualities: accuracy, repeatability, and a credible safety case.