STRUCTURAL
HEALTH &
MONITORING
MEMS accelerometers with sub-µg/√Hz noise floors for ambient vibration bridge modal analysis; GPS PPS synchronisation achieving sub-5µs inter-node timing for coherent cross-spectral analysis across 200-sensor arrays; FDD, EFDD, and SSI modal parameter extraction firmware with MAC-based damage index trending; vibrating wire piezometer and inclinometer electronics for dam and slope monitoring; GNSS carrier phase displacement for sub-millimetre structural movement; rainflow cycle counting per ASTM E1049 with S-N curve fatigue accumulation; and Iridium SBD, LTE-M, and solar-powered LoRaWAN telemetry for remote monitoring.
The Engineering Problem
The Gap Between Measuring Vibration and Extracting Structural Condition Information Is the Entire Engineering Problem
An accelerometer whose noise floor exceeds the ambient vibration amplitude at the structure's modal frequencies produces measurements dominated by sensor noise — and modal analysis from noise is random frequency content with no structural significance. A distributed system where two nodes sample without GPS PPS synchronisation produces a phase relationship that drifts with temperature and oscillator tolerance, rendering coherent cross-spectral analysis meaningless for mode shape identification. At 200 sps, 1% phase accuracy requires timestamps accurate to better than 50µs — which network time protocol cannot reliably achieve over wireless links. A power budget designed for average vibration activity will exhaust the battery during sustained high-amplitude monitoring after a seismic event, at precisely the moment structural data is most valuable.
Bridge and dam owners in North America, Europe, and Asia face deteriorating infrastructure age, constrained maintenance budgets, and rising traffic and environmental loading — creating demand for continuous, quantitative structural condition data to justify maintenance investment over periodic visual inspections with fundamentally limited sensitivity to subsurface and fatigue damage. MEMS sensor cost reduction is enabling dense arrays on structures that were previously too costly to instrument, demanding multi-channel GPS-synchronised hardware at infrastructure budget cost points. Machine learning and structural analytics platforms are enabling automated condition-sensitive feature extraction — demanding monitoring hardware with edge FDD and SSI processing to transmit condition indicators rather than 50 GB of raw acceleration data per bridge per year that no asset manager can use without a structural dynamics specialist.
We design structural monitoring hardware from the condition assessment objective outward — damage modes to detect first, then vibration or deformation characteristics that carry information about those modes, sensor noise and bandwidth requirements to resolve them, GPS PPS synchronisation architecture for coherent multi-node analysis, edge processing to extract condition-sensitive modal parameters, and the power and telemetry system that sustains all of this continuously without scheduled maintenance visits. Civil infrastructure owners, bridge and dam safety technology companies, geotechnical monitoring vendors, wind energy companies, offshore structure operators, railway infrastructure companies, and mining slope stability vendors all need this engineering depth.
Structural Health & Vibration Monitoring Categories We Build
From GPS-synchronised 200-sensor bridge modal analysis systems to vibrating wire dam piezometer networks to acoustic emission slope failure precursor monitors to offshore jacket fatigue strain monitoring — every structure type, every sensing technology, every deployment environment.
Bridge & Civil Infrastructure Monitoring Systems
Dam Safety & Geotechnical Monitoring Electronics
Slope Stability & Landslide Monitoring
Building, Urban Structure & Post-Earthquake Assessment
Wind Energy Structure Monitoring Electronics
Railway & Transportation Infrastructure Monitoring
Industrial Plant, Offshore & Marine Structure Monitoring
Geotechnical Ground Improvement & Foundation Monitoring
Vibration & Accelerometer Sensing
Low-noise MEMS accelerometer electronics with noise floor below 1µg/√Hz for ambient vibration monitoring at micro-g amplitude structural response levels typical of bridge and building monitoring; IEPE constant current excitation electronics for piezoelectric accelerometer conditioning with 0.1 Hz to 10 kHz bandwidth; triaxial accelerometer arrays for three-dimensional structural response and 3D mode shape extraction; strong motion accelerometer electronics for ±2g to ±20g peak ground acceleration; and 24-bit sigma-delta ADC at 100–10,000 sps with anti-alias filter design for accurate spectral analysis at all structural modal frequencies.
Strain & Displacement Sensing
Wheatstone bridge strain gauge signal conditioning with 24-bit ADC for sub-microstrain measurement; VW strain gauge frequency measurement from 400 Hz to 4500 Hz with simultaneous thermistor temperature measurement; ratiometric frequency firmware for temperature-compensated VW strain calculation; FBG interrogator interface for quasi-distributed strain sensing; LVDT signal conditioning for local structural displacement; and joint meter and crack gauge electronics for crack opening and settlement monitoring.
Geotechnical & Pore Pressure Sensors
VW piezometer frequency measurement electronics for pore water pressure monitoring in dam bodies, foundation soils, and retaining structures — 400 Hz to 4500 Hz range achieving sub-0.01m water head resolution; MEMS digital inclinometer with ±0.001° resolution and temperature coefficient below 0.001°/°C for long-term continuous tilt monitoring; earth pressure cell VW frequency electronics for lateral and vertical soil pressure; extensometer electronics for deep-seated ground movement; and acoustic emission waveguide sensor electronics with hit detection firmware for soil and rock slope creep and rupture precursor monitoring.
GNSS & Geodetic Displacement
Multi-constellation GNSS receiver electronics (GPS, GLONASS, Galileo, BeiDou) with low-noise RF front end for structural displacement monitoring; carrier phase GNSS processing interface for sub-millimetre displacement using network RTK or PPP correction services; GNSS antenna placement engineering for monitoring environments with signal obstruction from bridge cables, tower elements, and facades; dual-frequency GNSS for ionospheric delay correction; and GNSS and accelerometer fusion firmware combining high-frequency dynamic response from accelerometers with absolute displacement from GNSS carrier phase.
Time Synchronisation & Distributed Acquisition
GPS PPS synchronisation electronics providing sub-microsecond timestamp accuracy across all nodes — enabling coherent cross-spectral analysis at 200 sps where 1% phase accuracy requires timestamps accurate to better than 50µs; IEEE 1588 PTP Ethernet synchronisation for wired networks; GPS-disciplined oscillator for remote nodes with temporary GPS signal loss; simultaneous multi-channel ADC sampling for coherent phase measurement across each acquisition node; and event trigger electronics for synchronised waveform capture on seismic, blast, and impact threshold crossings.
Structural Condition Assessment Firmware
FDD firmware for natural frequency and mode shape extraction from ambient vibration PSD matrices via singular value decomposition; EFDD firmware for damping ratio estimation; SSI firmware for state-space model-based modal parameter extraction from closely-spaced modes; MAC calculation for mode shape correlation across monitoring periods; temperature and traffic load normalisation firmware for frequency-temperature and frequency-loading correlation correction; damage index calculation from normalised frequency shift and MAC change; and rainflow cycle counting per ASTM E1049 with S-N curve integration for remaining fatigue life estimation.
Power & Remote Telemetry
Solar MPPT energy harvesting validated against deployment latitude seasonal insolation minimum with battery and panel specification verified by thermal chamber test; primary Li-SOCl2 power budget calculated at the structure's ambient temperature profile, not at room temperature; adaptive duty cycle firmware modulating sampling rate and transmission frequency based on energy budget and structural event significance. LoRaWAN Class A for wide-area monitoring; LTE-M and NB-IoT for urban structures; Iridium SBD and Swarm satellite for remote bridge, dam, and slope monitoring beyond terrestrial network coverage.
Environmental Qualification & Long-Term Deployment
IP67 and IP68 sensor node enclosures for outdoor structural monitoring in rain, flooding, and submersion; IP69K for monitoring electronics subject to high-pressure jet cleaning; MIL-STD-810 shock and vibration qualification for monitoring near impact and blast loading; -40°C to +70°C extended temperature range for arctic through tropical deployment; IEC 61000-4 EMC immunity for monitoring near high-voltage infrastructure; 316 stainless and marine-grade aluminium enclosures for offshore and coastal deployment; and 10-20 year design life for structure-embedded sensors and electronics.
Chipsets & Platforms
Platforms, ICs & Standards
Tested silicon and proven stacks — no experimental platform dependencies.
Bridge, Civil Infrastructure & Ambient Vibration Modal Analysis
Sub-µg/√Hz Noise Floor. GPS PPS Synchronisation. FDD · SSI · MAC. Cable Force. GNSS Displacement. Rainflow Fatigue.
A long-span suspension bridge has fundamental modes below 0.1 Hz where measurements must discriminate structural response from accelerometer DC drift, and higher modes above 5 Hz where closely-spaced cable modes require high frequency resolution spectral analysis. FDD extracts natural frequencies as peaks in the singular value spectrum of the PSD matrix; MAC calculation between time segments measures modal parameter estimation consistency. Frequency resolution of 0.001 Hz — required for closely-spaced modes — determines the minimum data segment length. Closely-spaced modes appearing as a single broadened peak require EFDD or SSI: SSI does not require the white-noise excitation stationarity assumption of FDD, making it more robust when traffic loading creates non-stationary excitation. Ankh designs bridge modal analysis electronics from the structural dynamics level: sub-µg/√Hz MEMS arrays, GPS PPS synchronisation, FDD/EFDD/SSI modal extraction, MAC damage index with temperature normalisation, cable stay force monitoring, GNSS carrier phase deck displacement, and rainflow fatigue accumulation at fracture-critical sections.
Dam Safety, Geotechnical & Slope Stability Monitoring
VW Piezometer. ±0.001° Inclinometer. Acoustic Emission Slope. ICOLD Bulletin 158. Iridium Telemetry. EAP Alerting.
Dam safety regulatory frameworks require continuous monitoring of pore water pressure, seepage, deformation, and seismic response with defined threshold levels triggering Emergency Action Plan activation. The geotechnical measurements involved — VW piezometer readings, inclinometer tiltmeter readings at ±0.001° resolution, settlement gauge readings at sub-millimetre precision — are made in environments among the harshest for electronics deployment. Ankh designs VW piezometer frequency measurement electronics achieving sub-0.01m water head resolution across 400 Hz to 4500 Hz; MEMS digital inclinometer electronics with ±0.001° resolution and temperature coefficient below 0.001°/°C; acoustic emission waveguide sensor electronics with hit detection firmware for slope creep and rupture precursor monitoring — AE hit rate and amplitude increase progressively during accelerating creep hours to days before visible surface movement. All with Iridium SBD primary and LTE-M backup achieving 99.97% data delivery for regulatory reporting continuity.
Wind Energy, Industrial Plant & Offshore Structure Monitoring
Wind Turbine Modal Tracking. Offshore Jacket Fatigue. DNV-RP-C203. Rainflow · S-N · Palmgren-Miner. Subsea Sensing.
Wind turbines, offshore platforms, and industrial process structures are all subject to large-magnitude, high-cycle fatigue loading in environments hostile to electronics deployment and maintenance access. Offshore structural fatigue monitoring operates within the DNV-RP-C203 framework: the stress concentration factor (SCF) at tubular joints amplifies nominal stress to hot-spot stress at fatigue-critical weld toes — an SCF of 3.0 amplifies a 10 MPa nominal range to 30 MPa hot-spot stress, reducing fatigue life by approximately 27× for a slope of -3 on the SN curve. The Palmgren-Miner linear damage rule integrates the fatigue life fraction consumed by each stress cycle: D = Σ(ni/Ni). Rainflow cycle counting per ASTM E1049 provides the ni values from measured strain histories. Ankh implements the complete offshore fatigue monitoring framework — SCF-corrected hot-spot stress, rainflow cycle counting, DNV-RP-C203 SN curve integration, and Palmgren-Miner damage accumulation — as firmware converting measured strain into fatigue life consumed per monitoring period.
Why Structural Monitoring Engineering Teams Choose Ankh
Sensor Noise Floor Engineered for the Structural Signal
A bridge in wind loading generates ambient accelerations of 0.01g to 0.1g at the deck, decreasing to 0.001g to 0.01g at the piers and abutments where structural condition information is most critical. An accelerometer with a noise floor of 100µg/√Hz at 200 sps produces an RMS noise contribution of 1.4mg — overwhelming the signal at sensor locations with only 1mg of structural response. Ankh selects accelerometer technology and designs signal conditioning with the noise floor budget that keeps the structural signal visible above the noise at every sensor location — starting from the structural dynamics of the specific structure, calculating expected signal amplitude at each location, and working backward to the sensor noise floor requirement.
GPS PPS Synchronisation as the Enabling Architecture for Distributed Modal Analysis
Mode shapes are identified by the phase relationships between sensor responses across a structure. Phase measurement requires timestamps accurate to a fraction of the sampling period — at 200 sps, 1% phase accuracy requires timestamps accurate to better than 50µs. GPS PPS provides sub-microsecond accuracy across all nodes regardless of geographic separation; NTP or periodic wireless resynchronisation cannot achieve this, and mode shapes extracted from such data will be systematically distorted by timing errors. Ankh designs GPS PPS synchronisation into every multi-node structural monitoring architecture as a non-negotiable first-order system requirement, not an optional precision enhancement.
Structural Condition Indicators at the Output, Not Raw Data
A monitoring system that stores 50GB of raw acceleration data per year per bridge provides data that no asset manager can use for condition trending without a structural dynamics specialist reviewing each dataset manually. A system that stores daily FDD natural frequency and damping ratio estimates with temperature-corrected MAC values requires approximately 100KB per day and can be reviewed on a dashboard in 5 minutes. Ankh designs the edge processing that extracts FDD modal parameters, calculates MAC values, normalises for temperature and loading variation, and flags anomalies from statistical process control — so the monitoring system delivers condition indicators, not a data science project.
Power Budget Validated for the Specific Deployment's Energy Environment
A solar-powered monitoring node in northern Norway receives 0 kWh of solar energy for 6 weeks during polar winter; a node in central Spain receives 10× the Norway winter minimum. A primary battery power budget calculated at room temperature does not apply to a bridge pier that reaches -40°C in January, where Li-SOCl2 capacity is reduced by 30% and self-discharge is accelerated. Ankh calculates the power budget for the specific deployment latitude, seasonal insolation minimum, and ambient temperature range — and validates the energy balance in a thermal chamber before committing the battery and panel specification for a remote installation where power failure means months of monitoring data loss.
200-Sensor Cable-Stayed Bridge SHM System — 99.3% Data Completeness, 3 Cable Tension Events Detected
A national highway agency needed a 200-sensor structural health monitoring system for a 680-metre main span cable-stayed bridge — requiring sub-µg/√Hz MEMS noise floor, GPS PPS synchronisation across 12 distributed acquisition units spanning 680 metres, 0.001Hz FDD frequency resolution for closely-spaced mode separation, and continuous cable force and GNSS displacement monitoring without maintenance access.
64-channel MEMS arrays at 0.5µg/√Hz noise floor at 200 sps with 24-bit ADC; GPS PPS synchronisation achieving sub-5µs inter-node timing; FDD and EFDD modal parameter extraction on ARM Cortex-A edge gateway at 15-minute intervals; MAC damage index with temperature and WIM load normalisation; cable force monitoring from 32 stay cables at ±0.5% accuracy; GNSS carrier phase displacement at 4 deck locations at ±3mm; rainflow cycle counting on 8 girder sections; and LoRaWAN telemetry with LTE-M backup and solar MPPT.
- 99.3% data completeness across 18 months of continuous operation — zero monitoring outages from power or communication failures
- 3 cable tension asymmetry events detected and flagged for inspection investigation — 2 confirmed as anchor corrosion precursors
- 0.001Hz FDD frequency resolution achieved — closely-spaced modes at 0.312Hz and 0.334Hz successfully separated using EFDD
- GPS PPS sub-5µs synchronisation validated across full 680-metre span — mode shapes consistent with FEM predictions
Dam Safety Monitoring & EAP Alert System — 78m Embankment Dam, 99.97% Data Delivery, Regulatory Acceptance
A water authority needed an integrated structural and geotechnical monitoring system for a 78-metre high-consequence embankment dam — requiring VW piezometer, inclinometer, settlement gauge, acoustic emission, and seismograph electronics with regulatory-grade data continuity, multi-tier EAP alerting, and Iridium SBD telemetry for operation beyond terrestrial network coverage.
24-channel VW piezometer monitoring at sub-0.01m water head resolution; MEMS inclinometer array at 12 cross-section locations at ±0.001° resolution with temperature coefficient 0.0008°/°C validated from -20°C to +50°C; 6-channel liquid settlement gauge electronics; acoustic emission monitoring at 4 locations with hit rate trending; seismograph with PGA and response spectrum; multi-tier EAP alerting; Iridium SBD primary with LTE-M backup; and solar MPPT with 12-month autonomous operation after solar failure.
- 99.97% data delivery across full monitoring period including 3 network outage events — Iridium SBD maintained regulatory reporting continuity
- Regulatory acceptance achieved within 16-week deployment programme for high-consequence dam classification
- Acoustic emission hit rate increase detected 14 hours before inclinometer response in one rainfall event — earliest warning lead time in dam safety programme history
- ±0.001° inclinometer resolution validated in thermal chamber — temperature coefficient 0.0008°/°C confirmed across -20°C to +50°C
Building structural health or vibration monitoring electronics? Let's read the structure.
Sensor noise floor engineered from structural signal amplitude at each monitoring location — not from a sensor datasheet. GPS PPS synchronisation as the non-negotiable enabling architecture for coherent distributed modal analysis across every monitoring node. Full-stack delivery from accelerometer signal conditioning through FDD and SSI modal analysis firmware through rainflow fatigue accumulation through satellite telemetry through long-term structural condition management reporting.
Quote Your Structural Monitoring Project