How to Build a DIY Drone Magnetometer System

Drone-based magnetic surveying is rapidly becoming one of the most effective ways to detect buried metal objects, map subsurface anomalies, and perform geophysical exploration over large areas. With modern UAV platforms and advanced magnetometer technology, it is now possible to create a powerful DIY drone kit for professional-grade surveys.

In this guide, we explain how to build a DIY Drone Magnetometer Kit using the FG Sensors 3-Axis Magnetometer Kit, combined with PolarWave AutoPilot for automated scanning and PolarWave DATAfor survey analysis and visualization.

Why Use a Magnetometer on a Drone?

A drone equipped with a magnetometer allows you to measure tiny disturbances in Earth’s magnetic field caused by underground objects such as:

• Buried metallic structures
• Iron deposits and mineral zones
• Archaeological remains
• UXO (unexploded ordnance)
• Magnetic anomalies in geophysical surveys

Unlike handheld detectors, UAV-based magnetometer surveys cover large terrain quickly and provide high-resolution mapping from above.

What is the FG Sensors 3-Axis Magnetometer Kit?

The FG Sensors 3-Axis Kit is a high-sensitivity fluxgate magnetometer solution designed for precise measurement of magnetic fields in three dimensions:

• X-axis
• Y-axis
• Z-axis

Key Specifications

The kit provides:

• Magnetic field range: ±100 μT
• High bandwidth: up to 1 kHz
• Very low power consumption: <15 mW
• GPS compatibility for positioning
• Data Logger
• SD card support for data logging
• USB/UART outputs for real-time integration
• Optional gradiometer (dual sensor) configuration

What is in the package:

• FGA DataLogger Unit
• GPS Antenna
• USB C Data / Power Cable
• DB9 connector for UART and Power
• SD Card (32GB)
• 1 or 2X Bartington100 MAG-649 | 3-Axis Magnetometer Sensor
• 1 or 2X RJ45 Ethernet Cable

This makes it an ideal foundation for building an aerial magnetic scanning platform.

Core Components for a DIY Drone Magnetometer Kit

To assemble your own UAV magnetometer survey system, you will need the following:

1. Drone Platform

Choose a UAV with sufficient payload capacity and stable autonomous flight capability, such as:

• DJI Matrice series
• Custom hexacopters
• Industrial survey drones

2. FG Sensors 3-Axis Magnetometer Kit

This is the primary sensing instrument. It captures real-time magnetic field variations in three directions simultaneously.

3. Non-Metal Sensor Suspension or Boom Mount

To avoid interference from drone motors, wiring, and electronics, the magnetometer must be mounted:

• Below the drone on a suspension line
• On a carbon-fiber boom arm
• Away from battery and ESC cables

Proper separation ensures accurate magnetic measurements.

We have mounted the system on plastic cable tray.

4. PolarWave AutoPilot (Survey Automation)

Once the sensor is installed, consistent flight patterns are essential for producing usable magnetic maps.

Polarwave AutoPilot enables:

• Automated grid missions
• Constant altitude scanning
• Repeatable survey paths
• Accurate waypoint navigation

Instead of manual piloting, AutoPilot ensures professional-grade survey coverage and consistent sampling.

5. Polarwave DATA (Data Processing & Mapping)

After the flight, magnetometer data must be transformed into meaningful underground anomaly maps.

Polarwave DATAprovides:

• Magnetic field visualization
• Survey line processing
• 2D and 3D anomaly mapping
• Data alignment with GPS coordinates
• Export tools for geophysics workflows

You can use any data processing sofware for processing the output format is saved in.csv

Step-by-Step DIY Build Process

Step 1 — Assemble the FG Sensors Kit

Begin by connecting:

• Magnetometer sensor module
• Data acquisition interface
• GPS antenna (if used)
• SD logging or UART output

Confirm that the sensor is calibrated and functioning before flight.

To calibrate sensor use our documentation.

Step 2 — Mount the Sensor Correctly

Use a lightweight non-metal mount system:

• Nylon suspension ropes
• 3D-printed brackets
• Carbon fiber rods
• Mount with tape on the drones legs

Maintain distance from magnetic noise sources such as motors and power lines.

Watch tutorial video

Step 3 — Configure PolarWave AutoPilot Mission

Using AutoPilot, create a survey plan:

• Define the target area boundary
• Set line spacing (typically 1–5 m)
• Choose flight altitude (2–10 m depending on target depth)
• Enable constant-speed scanning

Automated missions improve resolution and reduce human error.

Step 4 — Fly the Survey and Record Data

During flight, the FG Sensors kit measures:

• Magnetic field intensity
• Directional flux changes
• Location and altitude (with GPS)

Data is stored for post-processing.

Step 5 — Process Results in Polarwave DATA

After landing:

• Import the recorded magnetometer data
• Sync GPS coordinates
• Apply filtering and anomaly correction
• Generate magnetic heatmaps
• Identify underground targets or structures

Polarwave DATA makes it possible to interpret anomalies clearly for exploration or surveying applications.

Advanced Upgrade: Dual Sensor Gradiometer Mode

FG Sensors also supports a dual-sensor configuration, allowing you to build a magnetic gradiometer system for:

• Higher sensitivity
• Better noise suppression
• Clearer anomaly detection

This is especially valuable for professional geophysical work.

Applications of DIY Drone Magnetometer Surveys

A drone kit using FG Sensors + Polarwave software can support:

• Treasure and buried metal exploration
• Archaeological magnetic mapping
• UXO detection surveys
• Mineral and geological research
• Infrastructure and pipeline inspection
• Environmental anomaly studies

Conclusion

Building a DIY drone magnetometer kit is now more achievable than ever with the FG Sensors 3-Axis Magnetometer Kit, combined with mission automation through PolarWave AutoPilot and professional data interpretation using PolarWave DATA.

With the right setup, UAV magnetic scanning becomes a powerful tool for detecting subsurface anomalies and performing high-resolution surveys efficiently across large areas.