Arboriculture & Tree Surgery ยท Tree crowns, stems, and structural defects

AI Decay Detection with Sonic Tomography and Resistance Drilling Data

This AI use case detects decay in tree stems using sonic tomography and resistograph data, integrated across design, build, operation, maintenance, and safety stages.

By Suhas BhairavUpdated 4 min read

AssetTree crowns, stems, and structural defects
AssetRoots, soil, and trees near construction
AssetClimbing, rigging, and lifting equipment
AssetChainsaws, pole saws, and cutting tools
AssetChippers, stump grinders, MEWPs, cranes, and vehicles
AssetWorksite set-up, traffic management, and utilities
AssetTree planting, nursery stock, and establishment
BusinessTree surveys, reports, and planning consultancy
BusinessQuotes, clients, and contracts
BusinessPermissions, wildlife law, and safety records
BusinessStaff, fleet, scheduling, and finance
1sonic tomograph scanner2resistograph probe3drill core samples4decay extent mapping software5field data logger6timber condition logbook

The short answer

Decay detection with sonic tomography and resistance drilling data uses AI to read sonic tomograph scans and resistograph traces, estimate residual wall thickness and decay extent, and decide on pruning, felling, or further investigation. It stays with people as a risk profile, work orders, and verification records.

Who it's for: Owners and operators of tree care businesses, arboricultural consultants, utility vegetation managers, council tree officers, and contracts managers.

Why it matters

Without this, decay risks may go unnoticed, leading to unexpected failures, unsafe pruning or removal decisions, and failed audits due to missing decay records and plant health data.

From design to safety

  1. Design

    AI informs survey and design decisions

    Reads sonic tomography data, resistograph traces, residual wall thickness, and decay extent to guide species selection, work methods, and planning job sequencing. It integrates BS 3998 guidance, checks crown-to-stem balance, and flags potential root protection area conflicts with proposed layout.

    • sonic tomograph scanner
    • resistograph probe
    • drill core samples
    • decay extent mapping software
  2. Build

    Site setup supports remote sensing integration

    Configures data capture workflows, calibrates scanners, and aligns trenching or excavation plans with identified decay zones. Produces a pre-work decay clearance checklist and marks hazard zones on site drawings.

    • sonic tomograph scanner
    • drill core samples
    • field data logger
    • timber condition logbook
  3. Operation

    On-site assessment and action planning

    Continuously reads live data to adapt rigging, pruning, dismantling, or removal strategies based on estimated decay. Generates alternate work orders, short-interval re scans, and a visibility layer for ground staff.

    • decay extent mapping software
    • residual wall thickness gauge
    • field data logger
    • timber condition logbook
  4. Maintenance

    Ongoing monitoring and data refresh

    Schedules re-inspections, updates decay maps, and integrates new resistograph readings to reassess risk. Tracks sensor calibration intervals, data integrity checks, and archival of prior maps for trend analysis.

    • decay extent mapping software
    • residual wall thickness gauge
    • field data logger
    • timber condition logbook
  5. Safety

    Safeguards and regulatory validation

    Ensures readings are signed off by a qualified arborist, aligns with LOLER, BS 3998, and utility clearance; records public protection measures. Maintains a safety file with decay data underpinning permit decisions.

    • sonic tomograph scanner
    • resistograph probe
    • drill core samples
    • timber condition logbook

Part by part

  1. 1

    sonic tomograph scanner

    Watch for
    changes in detected wave velocity indicating internal decay
    AI action
    flag anomalies exceeding threshold and trigger decay extent analysis; store timestamps and calibration data in audit trail; export to decay extent maps with geo reference
  2. 2

    resistograph probe

    Watch for
    irregular resistance patterns suggesting hollowing or internal decay
    AI action
    generate decay extent map and severity ranking; apply confidence scores and cross-check with TOMO data; request core depth supplementation if gaps appear
  3. 3

    drill core samples

    Watch for
    reduced residual wall thickness along core segments
    AI action
    mark samples for laboratory confirmation and update decay model; log bore path coordinates and sample IDs for traceability
  4. 4

    decay extent mapping software

    Watch for
    inconsistent integration of scan and drill data
    AI action
    update decay contour visualization and risk zones for work planning; create layer-rich reports including 2D/3D views and cross-sections
  5. 5

    field data logger

    Watch for
    gaps in sensor data or timestamp misalignment
    AI action
    synchronize data streams and timestamp entries for audit trail; flag data gaps and prompt crew to reseal loggers after maintenance
  6. 6

    timber condition logbook

    Watch for
    missing records of inspections and decisions
    AI action
    auto-fill activity log with AI-derived notes and sign-off prompts; attach photos, GPS tags, and job codes

Worked example

Catching a decline in stem integrity before a planned prune

Illustrative scenario with sample data.

A mid-size urban tree shows signs of internal decay; pre-prune AI reads multiple data streams to decide safe work methods, considering utilities and public safety.

Signal in

sonicVelocity: 1680 m/s; resistographDepths: [2,5,9,12] mm; residualWall: [12,11,9] mm; decayExtent: moderate at mid-stem; location: 4 m above grade; borePaths: [id-101, id-102]; project: street tree upgrade

System out

Decay map indicates moderate internal loss; risk zone 60 cm above ground; recommended avoidance of high-tall cuts; plan for reduced-pruning height and follow-up re-inspection; prep work order PR-77 and safety briefing.

Human sign-off: Arboricultural consultant reviews the AI output, confirms decay extent, aligns with BS 5837 constraints, approves alternative pruning strategy and monitoring plan; signs off the work order and informs the utility controller.

How to roll it out

  1. Phase 1

    Weeks 1 to 4: Baseline

    Install sensors, calibrate devices, and establish data capture workflows; validate models against known decayed samples.

  2. Phase 2

    Weeks 5 to 8: Field testing

    Run initial assessments on a sample of target trees; adjust thresholds and reporting formats for crews.

  3. Phase 3

    Weeks 9 to 12: Full deployment

    Scale AI processes across all suitable trees; integrate decay outputs into planning, execution, and safety documentation.

Where people stay in charge

  • Decisions affecting safety and work method must be signed off by a qualified arborist or the local authority tree officer.
  • Data interpretation thresholds must be validated against standard references (BS 3998, BS 5837) and LOLER compliance before actions.
  • Records and reports created by AI must be reviewed, corrected if needed, and archived by human supervisors.

Questions owners and crews ask

How does AI decay detection help with planning jobs and plant health decisions?

AI reads sonic tomograph scans and resistograph traces to estimate decay extent and residual wall thickness, guiding work methods, species considerations, and safety planning, with human sign-off on final decisions.

What data feeds are required for AI to detect decay accurately?

Data from sonic tomograph scans, resistograph traces, residual wall thickness measurements, decay extent estimates, bore path data, and field notes feed the AI model; calibration data ensures accuracy.

Who validates AI-driven decay assessments in practice?

A qualified arborist or the local authority tree officer reviews AI outputs, confirms risk zones, and approves or revises the proposed work plan.

What records are produced to support compliance and audits?

Decay maps, wall thickness trends, inspection logs, field notes, sign-off records, and work method changes are stored for regulatory compliance and audits.

Sources and further reading

  1. HSE: LOLERLifting equipment regulations explain thorough examinations for rigging and climbing kit used in tree work.
  2. Arboricultural Association: Registered ConsultantsGuidance on registered consultants covers tree surveys, reports, and expert witness standards.

Work with Suhas Bhairav

Let's find where AI pays back on your tree care businesses.

Tree surgery firms, consultants, and utility arborists bring me the problem that keeps costing them lost jobs, injuries, or audit findings. We map it to one system you can ship.

  • A 30-minute working call, not a pitch
  • You leave knowing the first system worth building
  • Built around the systems, records, and people you already have