Advanced Drone Surveying with SPH Engineering: Airborne GPR, Bathymetry, Methane Detection & Magnetometry

Why an integration layer matters

Most survey-grade sensors were never designed to fly. They expect stable power, precise georeferencing, constant ground clearance, and a clean data path back to the operator. SPH Engineering's value is the glue between an off-the-shelf DJI airframe and these demanding payloads: the SkyHub onboard computer handles power, sensor triggering, and data logging, while UgCS handles mission planning and automated flight. Together they let a single DJI M300, M350, or M400 RTK carry radically different instruments without custom engineering for each one. Browse the full lineup in our SPH Engineering integrated systems collection.

The result is repeatable, georeferenced data instead of a sensor bolted to a drone. Every trace, ping, or gas reading is time-stamped against GNSS and altimeter values, so the data is survey-ready rather than something you have to reconcile after the flight.

Airborne ground-penetrating radar (ZondAero)

The ZondAero 1000 NG GPR is a single-channel, shielded-antenna radar tuned to a 1000 MHz center frequency for high-resolution, shallow surveys. At that frequency you trade depth for detail: penetration is on the order of up to about 1 metre from the ground in average soil, and up to roughly 0.5 m with the antenna elevated about 0.5 m, which makes it ideal for snow and ice profiling, detecting shallow objects, and thin-layer mapping. The airborne unit weighs about 1.8 kg without the mounting kit and ships with mounts for the DJI M300/M350 RTK or M400.

Frequency selection is the single most important decision in a GPR survey. Lower-frequency ZondAero models (the LF NG ships with 100, 150, and 300 MHz antennas and is tested across a 50-400 MHz range) reach much deeper, on the order of 10 m at altitude and up to roughly 20 m from the ground in favourable soil, but resolve less fine detail, while the 1000 MHz unit resolves centimetre-scale features near the surface. For a deeper treatment of that trade-off, see our guide on comparing drone GPR frequencies for different soil types, and the full workflow walkthrough in airborne ground penetrating radar with ZondAero. You can also compare the broader range in our ground-penetrating radar system collection.

Drone bathymetry and multibeam echo sounding

For hydrographic work, the Cerulean Surveyor 240-16 MBES brings multibeam coverage to small, agile platforms. It operates at 240 kHz with a 16-element receive array, sweeping an 80-degree cross-track swath. Angle-of-arrival processing delivers around 1-degree cross-track angular resolution, and a built-in IMU applies pitch and roll compensation so results hold up in chop. The unit is compact at roughly 790 g in air, draws 10-30 V at about 5 W idle and 15 W while pinging, and is suggested for ranges up to about 100 m.

Single-beam EchoLogger sounders cover simpler depth-profiling tasks, while the Surveyor 240-16 is the tool when you need a full swath and bottom detail. Bathymetry is also where drone and USV deployment pays off most directly: surveying a hazardous or inaccessible waterbody from the bank rather than putting a crewed boat on it. Our drone bathymetry guide covers the full survey workflow, and the tailings pond case study walks through a representative Canadian operation.

Laser methane detection (Laser Falcon)

The Laser Falcon remote methane leak detector uses TDLAS (tunable diode laser absorption spectroscopy) to measure methane along the laser path without ever entering the gas cloud. The beam reflects off the ground or infrastructure and returns a column concentration reading, with a fast measurement rate of up to about 40 readings per second and reliable detection at standoff distances commonly in the tens of metres (roughly 10 to 80 m depending on conditions). Because measurement is remote and fast, crews can scan pipelines, wellpads, LNG facilities, and storage sites from a safe altitude and at survey speed.

The Falcon integrates with DJI M300/M350 and other enterprise platforms, logging every reading against GPS via SkyHub so leaks are pinpointed on a map rather than flagged vaguely. For the operational picture, see our guide on rapid methane leak detection at LNG and oil & gas sites.

Magnetometry

SPH Engineering also integrates a family of airborne magnetometers for UXO search, mineral exploration, utility mapping, and archaeology. Options range from single-sensor fluxgate systems through multi-sensor gradiometer arrays on horizontal booms, up to atomic total-field sensors for the highest sensitivity. As with the other payloads, UgCS provides magnetometer-specific survey functions and SkyHub logs the data, with laser or radar altimeters enabling low-altitude terrain following down to a few metres above ground.

SkyHub, UgCS, and true terrain following

The common thread across every system above is constant ground clearance. GPR antennas must stay low relative to the radar wavelength, magnetometers fall off sharply with distance, and methane and bathymetry both depend on consistent standoff. True terrain following solves this: SkyHub reads a downward radar or laser altimeter in real time and commands the DJI airframe to hold a set height above the actual ground surface, hugging hills, banks, and ditches instead of flying a flat GPS plane.

UgCS plans the mission and automates the survey lines; SkyHub runs the payload, logs the data, and drives terrain following. The role SkyHub plays in tying complex payloads together is covered in depth in our guide on the role of SkyHub in integrating complex drone payloads.

Choosing and specifying a system

The right configuration depends on the airframe you already fly, the depth or standoff your application demands, and whether you need real-time display or post-processed deliverables. Most of these systems are built around the DJI M300/M350/M400 RTK, so an existing enterprise fleet is usually the starting point. If you are scoping a project and want help matching sensor, frequency, and platform, request a quote and our team will spec a complete, flight-ready package.