By Olalekan Odunaike, Builder and Lead Developer, Worldwide Survey Dynamics
Accurate marine survey results depend on knowing where each sensor is installed, how it is oriented, and how its measurements relate to the vessel or vehicle reference frame. Those relationships must remain understandable when equipment is replaced, a deployment mechanism moves, or a configuration is transferred between survey systems.
Universal DimCon is a Windows desktop application developed by Worldwide Survey Dynamics to bring dimensional-control surveying, sensor geometry, uncertainty assessment, configuration checking, verification evidence, and configuration history into a controlled workflow. It connects a measured position or orientation to its source observations, uncertainty, review decision, and period of validity.
The software has progressed through its core and specialist development stages into release-candidate qualification. Its development now encompasses conventional vessels, hydrographic sensor suites, remote vehicles, articulated systems, and fleet configuration management. Final public commercial availability remains subject to release approval.
Why vessel dimensional control matters
A marine survey installation contains several physical reference points: GNSS antennas, an inertial sensor, sonar transmitters and receivers, acoustic positioning equipment, and the vessel reference origin. A lever arm describes the three-dimensional displacement between reference points. Mounting orientation describes how a sensor’s axes are aligned with the vessel.
Errors can enter through an incorrect measurement centre, a reversed sign, an unsuitable reference frame, an undocumented equipment change, or an offset applied twice. A small angular error can also grow into a substantial position error with distance. In an idealized geometric example, 0.1 degrees at 100 metres corresponds to approximately 0.175 metres of transverse displacement. This illustrates angular sensitivity; it is not a software accuracy claim.
Universal DimCon brings these relationships into one traceable model, giving surveyors a basis for assessing both the calculated geometry and the evidence supporting its use.
From observations to an approved configuration
The workflow follows the project’s PB-1 production baseline and its six connected stages:
- Define the project and responsibilities. Identify the platform, survey scope, units, reference systems, required evidence, tolerances, and responsible personnel.
- Assess the survey design. Examine control geometry, datum constraints, redundancy, recoverability, and the likely effect of observation errors.
- Import and normalize measurements. Preserve original evidence while creating structured measurement records with explicit units, uncertainty, timestamps, and provenance.
- Adjust and review the network. Solve the geometry and examine residuals, statistical tests, observability, reliability, and structural consistency.
- Derive the reference frame and sensor geometry. Establish the vessel origin and axes, solve lever arms and orientations, and assess uncertainty and operational effects.
- Configure, verify, report, and manage change. Check destination conventions, reconcile verification evidence, generate review packages, and maintain time-valid configuration states.
A failed check sends the project back for investigation, stronger observations, or an appropriate controlled review. Approval depends on the required gates and evidence for the selected workflow.
A consistent reference frame
Universal DimCon uses a fixed, right-handed internal frame: Forward, Starboard, Down, corresponding to positive X, Y, and Z. Lengths, angles, and time use explicit internal units. Source and destination conventions are handled through controlled mappings.
The vessel-frame solver fits a centreline and reference plane from accepted survey points. Explicit directional references resolve the forward and starboard signs, and selected accepted points establish the common reference point. The resulting orthogonal frame includes fit diagnostics and propagated uncertainty.
Sensor orientation is represented internally by proper rotation matrices and quaternions. Displayed roll, pitch, and yaw retain their declared convention. This supports consistent transformations through multiple frames and avoids treating a displayed angle triplet as a complete description of rotation semantics.
The algorithms behind the workflow
The PB-1 design registry contains 44 algorithm modules. The implemented development stages organize their mathematics around the following functions.
| Function | Method and practical purpose |
|---|---|
| Static network adjustment | Covariance-weighted nonlinear least squares using damped Gauss-Newton, explicit constraints, and rank diagnostics. Produces adjusted parameters, residuals, and covariance while exposing weak geometry. |
| Reference and feature geometry | Principal-component and orthogonal fitting for reference lines and planes, with circle, sphere, cylinder, and rigid-body fitting in the metrology suite. Supports reference-frame and mounting-feature definition. |
| Sensor orientation | Proper three-dimensional rotations and weighted rigid-body alignment, including Kabsch/Procrustes fitting where applicable. Connects measured features to the sensor frame. |
| Reliability analysis | Global and local statistical tests, redundancy numbers, minimum detectable bias, and external reliability. Evaluates how observation errors could affect reported geometry. |
| Robust diagnostics | Huber and Tukey diagnostic weights and residual flagging. Suspect observations remain visible; changes require explicit, auditable action. |
| Uncertainty propagation | Full-covariance propagation and deterministic-seed Monte Carlo. Translation and rotation uncertainty are composed in SO(3)/SE(3) tangent space, preserving relevant correlations. |
| Afloat geometry | A continuous tangent-space cubic trajectory with timestamped observations, attitude constraints, and optional instrument clock offsets. Addresses vessel motion during a measurement sequence. |
| Structural change | Rigidity checks, declared flexure-mode recovery, and temperature-driven scale attribution. Helps distinguish structural or thermal effects from local movement. |
These calculations support different engineering questions. A small residual does not, by itself, demonstrate that the network can detect a consequential blunder. Similarly, precise coordinates do not establish that a poorly constrained rotation is reliable. The workflow presents those distinctions for review.
Variance-component diagnostics can also identify differences between observation groups. Their suggested scale changes are recorded for consideration and do not automatically alter accepted measurement weights.
A sensor suite built around physical measurement centres
Different instruments measure from different physical reference points. Universal DimCon records those definitions with the source information needed to interpret them.
| Sensor or system | Geometry and quality controls |
|---|---|
| MBES | Separate transmit and receive centres, array or sector identity, centre separation, planarity, and flatness checks against declared tolerances. |
| GNSS | Surveyed antenna reference points, sourced frequency-specific phase-centre reductions, baseline geometry, and antenna-model uncertainty. |
| MRU, IMU, and INS | Three-dimensional lever arms and mounting orientation, with uncertainty and source provenance. |
| Gyro and heading | Circular-angle comparison between surveyed and indicated heading, explicit correction semantics, uncertainty, and validity conditions. |
| USBL | Acoustic-head reference geometry, pole or deployment state, navigation relationships, and separately recorded calibration evidence. |
| SBES and MTES | Individual transducer geometry, reference information, and evidence-linked bar-check assessment. |
| DVL and pressure sensors | Measurement-centre and uncertainty records, with nested navigation and payload relationships in the remote-vehicle suite. |
| LiDAR and cameras | Lever arms and boresight geometry linked to declared factory or field calibration references. |
The import architecture preserves both structured observations and source evidence. Controlled CSV routes provide deterministic interchange. Registering a source file as evidence does not imply that its proprietary native format has been decoded.
Safer transfer between survey system conventions
The Convention Guard and vendor compiler check axes, units, signs, origins, measurement centres, and rotation meaning before preparing configuration outputs. A round-trip check converts canonical geometry to the destination convention and back, testing whether the same physical geometry is recovered.
The documented profile registry includes a canonical open profile and full guarded mappings for Kongsberg SIS/EM, Seapath, and Applanix POS MV. Other families, including QPS, CARIS, EIVA, PDS, HYPACK/HYSWEEP, SBG, and BeamworX, carry profile-specific restrictions where angular semantics, device origins, or source-format behaviour need additional qualification.
The verified output route produces guarded machine-readable JSON and human-check CSV tables. Support for a convention profile should therefore be read according to its documented scope; it does not imply unrestricted proprietary configuration-file generation.
Keeping measured geometry separate from calibration
A central control in Universal DimCon is the calibration and verification firewall. A physical mounting transform, a configuration translation, a calibration correction, and an independent verification result remain separate records.
For example, an MBES patch-test result can be associated with the relevant configuration without silently replacing the surveyed mounting geometry. The same principle applies to gyro verification, USBL calibration, bar checks, latency estimates, and other commissioning evidence.
Each result declares whether it is a measured residual, measured error, correction to apply, or diagnostic value. The application checks tolerances and whether a correction has already been applied. A conflicting result returns the configuration to review, with the original observations and geometry preserved.
The sensor update and incomplete historical records
The P5.0.1 nullable-sensor hotfix addresses a practical problem encountered when entering historical vessel records: a source may provide sensor offsets without providing orientation or uncertainty for every field.
The hotfix preserves the difference between an unknown value and a supplied zero. Blank fields and declared missing-value tokens remain unavailable. A supplied value of 0.000 retains its numerical meaning. Malformed values still produce field-specific errors.
| Source entry | Meaning retained by the hotfix |
|---|---|
| Blank, NULL, N/A, NA, NOT_SUPPLIED, or UNKNOWN | The value was not supplied. |
| 0 or 0.000 | A zero value was explicitly supplied. |
| Valid numeric value | The supplied number is retained for validation. |
| Invalid numeric text | The record is rejected with a field-specific explanation. |
Availability is tracked separately for position, orientation, positional uncertainty, and angular uncertainty. Missing values remain explicit in JSON reports, and calculations that require unavailable inputs remain restricted.
This allows a historical suite to be recorded as partial or source-limited without being presented as operationally complete. The supplied regression example uses five Atlantic Surveyor sensor records to exercise this distinction. It is a historical-data regression case, not evidence of a new vessel survey or complete operational validation.
Remote vehicles and articulated systems
The remote-vehicle suite extends the frame model to USVs, ASVs, ROVs, AUVs, towfish, and towed sleds. It can represent relationships from the vehicle body through the INS and DVL to a sonar or other payload, with separate pressure-reference and transponder branches.
Each required link carries geometry, uncertainty, evidence, and a valid deployment state. Chain checks identify missing links, cycles, incompatible states, and excessive composed uncertainty.
The construction suite adds fixed, revolute, and prismatic joint models for equipment such as A-frames, cranes, booms, retractable poles, towpoints, and hydraulic rams. Mechanical limits and surveyed checkpoints constrain the model. Continuous evaluation requires a validated joint model and surveyed checkpoints bracketing the requested state.
Understanding uncertainty during operation
The operational-geometry layer keeps static survey geometry distinct from loading, thermal, mounting-repeatability, flexure, draft, and squat effects. Contributors carry declared values, uncertainties, and sources.
Mission scenarios examine the sensitivity of representative target or sounding positions to range, beam angle, lever arms, heading geometry, and operational conditions. This helps identify which uncertainty contributors deserve attention before deployment or acceptance.
The mission-impact calculation is an engineering sensitivity assessment. A complete survey-system uncertainty evaluation must also address the relevant acquisition, acoustic, environmental, and processing models. Project tolerances and operating limits remain explicit.
Reports that preserve the evidence
Universal DimCon generates a human-readable Vessel Survey Report and completeness dossier alongside a canonical JSON machine model, an XML transport view, and CSV evidence, configuration, verification, and audit manifests. SHA-256 hashes bind the outputs to their source records and package contents.
The review workflow records the responsible surveyor, reviewer, approver, decisions, and required acknowledgements. Packages move through controlled states, including draft, issued for review, approved, superseded, and archived. Approved historical evidence remains available after a replacement configuration is introduced.
Data-entry corrections also retain their history. Survey-network points and review decisions can be superseded or voided with a mandatory reason and audit linkage. The solver uses active point revisions while preserving earlier records for inspection.
The lifecycle layer resolves approved configurations by their effective dates and deployment states. It also supports configuration comparisons, benchmark recoverability records, and fleet summaries of overdue verification, expired certificates, changed configuration sources, and missing evidence. URDF, SDF, and glTF exports provide interoperability views of the approved geometry.
How the software has developed
The build programme has expanded the application while retaining a common mathematical core and evidence model.
| Development stage | Main capability introduced |
|---|---|
| P0 | Units, canonical schema, transformations, persistence, audit, adjustment, reliability, uncertainty, and numerical verification foundations. |
| P1 | Project setup, measurement records, network review, vessel and sensor geometry, vendor conventions, verification, reporting, and governance. |
| P2 | Further reliability, datum-invariance, nonlinear uncertainty, deformation, and operational-band assessment. |
| P3 and P4 | Advanced metrology and continuous-time afloat geometry. |
| P5 and P6 | Hydrographic sensor contracts and nested remote-vehicle geometry. |
| P7 and P8 | Articulated construction systems, operational geometry, draft, and mission-impact assessment. |
| P9 and P10 | System commissioning, configuration lifecycle, fleet summaries, digital-twin exchange, and API/plugin contracts. |
| RC1 development | Task-based interface, Windows deployment, recovery and compatibility controls, diagnostics, licensing workflows, and release qualification. |
| DEV-H2 core work | Strengthened mathematical acceptance tests, flexure and thermal models, cross-platform numerical qualification, and controlled core-freeze preparation. |
| P5.0.1 corrective package | Explicit missing-value handling and source-limited historical sensor records. |
P5.0.1 is a targeted correction to the sensor module within the broader application history. Its stage number should not be interpreted as a rollback from the later lifecycle and release work.
Desktop workflow and product status
The interface groups the work into Projects, Vessel Setup, Sensors, Data Import, Validation, Reports and Approval, Settings, and Advanced Tools. The mathematical core operates independently of the interface, and the project workflow is designed for offline use.
The current product position is a Windows release candidate undergoing controlled qualification. The core-acceptance framework specifies 18 PB-1 acceptance checks and a 923-test regression baseline, with a separate Windows/Linux numerical comparison. These are defined acceptance requirements; passing a particular build must be demonstrated by its corresponding test and evidence records.
Linux qualification is scoped to the headless mathematical core. It does not establish availability of a Linux desktop edition. Later corrective changes, including P5.0.1, require their own applicable regression checks against the current source.
Final commercial distribution remains subject to production signing, runtime redistribution approvals, signed-package clean-machine acceptance, and final release authorization. Worldwide Survey Dynamics will announce availability, licensing, supported configurations, and system requirements when that process is complete.
Who Universal DimCon is for
Universal DimCon is intended for hydrographic and offshore surveyors, vessel integration teams, dimensional-control specialists, marine geomatics engineers, shipyards, research organizations, remote-vehicle developers, and reviewers responsible for configuration assurance.
Its practical value is the connection between a measurement, its uncertainty, its source evidence, and the configuration in which it may be used. This gives teams a documented basis for installation checks, repeat surveys, equipment replacement, technical review, and historical reconstruction.
Product information and technical enquiries
To discuss Universal DimCon, demonstration opportunities, evaluation requirements, or technical collaboration, contact Worldwide Survey Dynamics.
Builder and Lead Developer: Olalekan Odunaike
Email: olalekan@wsd-survey.com
Website: wsd-survey.com
For the related heading-calibration product, read the GyroCal Offshore overview.