Dual-sensor core
A fluxgate magnetometer is tightly paired with motion sensing so attitude and platform dynamics can be treated as part of the measurement chain.
Prototype subsea magnetometer
Compact magnetic survey sensing for demanding subsea work.
TrueMag brings fluxgate measurements, tightly coupled motion sensing, and PTP time synchronization with NTP fallback over Ethernet into a small subsea-ready instrument concept.
The survey constraint
Better magnetic data starts with control over motion and timing.
Subsea survey operators need magnetometer instrumentation that fits existing AUV and ROV platforms while placing the sensor where the magnetic measurement is the strongest. That means supporting full-ocean-depth systems as well as smaller shallow-water, coastal, and transition-zone platforms, without relying on distant platform IMUs or imperfect motion compensation.
TrueMag tightly couples magnetic and motion sensing at the instrument level, preserving the data needed to push system performance further.
Measurement architecture
Compact hardware with synchronized survey data.
Small installation envelope
The complete unit fits in a Ø29 mm x 140 mm cylindrical housing. The pressure housing passed a 600 bar pressure test at RISE, Borås, in 2025.
Ethernet and precise timing
A direct Ethernet interface supports PTPv2 (IEEE 1588) with NTP fallback, aligning sensor data with the platform time base for integration into modern payload networks.
Multi-sensor operation
PTP enables simultaneous acquisition across multiple units with minimal phase lag, supporting accurate power-cable detection and compact gradiometer configurations.
Prototype measurements and integration
View product sheet (PDF)- Measured power consumption
- ≈0.8 W
- Current output rate
- 250 samples/s
- Outdoor noise density at 1 Hz (X / Y / Z)
- 0.750 / 0.659 / 0.159 nT/√Hz
Noise results are measured outdoor residuals from a 10-minute record on 2 October 2026. Environmental contributions remain; these are not intrinsic sensor noise limits. See the product sheet for measurement conditions and provisional specifications.
The analysis workflow builds on multi-year subsea magnetometer experience.
Case study
Buried offshore wind export cable detection
A compact prestudy on whether a low-noise AUV magnetometer can detect and position buried subsea power cables.
Case study
AUV UXO and mine-like target detection
A short feasibility note on survey altitude, target magnetic moment, and when passive magnetometry is credible for underwater ordnance screening.
Case study · UXO consultants
Vector data for UXO survey assessment
Three data advantages of three-axis fluxgate sensing, an illustrative scalar-versus-vector model, and a consultant-led qualification path.
Evaluation inquiries
Discuss subsea survey fit, integration, and prototype access.
UXO survey
Cable detection
Cable tracking
Marine minerals
Geophysical survey