Apertura

Assurance

Realism is not fidelity.

Synthetic data earns its place in model development only when there is evidence that it represents what the sensor would record — and a clear statement of where it does not. This is how we produce that evidence.

01 — Our position

Looking right is not the same as being right.

A synthetic image or recording can convince a person and still differ from real sensor data in ways a model will learn. A model can even learn to tell real data from synthetic data instead of learning the task.

We therefore treat every dataset as a claim that needs evidence: what was modelled, how it was checked, and where it should not be relied upon.

02 — Four commitments

What every dataset carries.

01

Documented physics

The models, parameters and simplifying assumptions behind each dataset are recorded, so a reviewer can see what the data can and cannot represent.

You receive: a physics summary and parameter record.

02

Measured validation

Where measured data is available, we quantify how far synthetic data sits from it. Where it is not, we say so plainly.

You receive: a validation report with the metrics behind it.

03

Data cards

Provenance, intended use, out-of-scope use, coverage and known limits, in a consistent structure your assurance team can cite.

You receive: a data card for every dataset version.

04

Ready for test and evaluation

Held-out synthetic test sets, organised by condition, for probing robustness and edge cases before field trials.

You receive: test sets and a coverage report.

03 — Measuring the gap

Four ways we measure synthetic against real.

No single metric is enough. We combine statistical and model-based measures, and report each one per condition rather than as a single headline figure.

Train on synthetic, test on real

How models trained on synthetic data perform on held-out measured data.

Distribution distance

How far synthetic and measured data sit apart in a learned feature space.

Real-versus-synthetic separability

How easily a classifier can tell them apart — a warning sign of artefacts a model could exploit.

Coverage

Which conditions, targets and sensor settings a dataset covers — and which it does not.

04 — The data card

One page your reviewers can rely on.

Each dataset version ships with a data card in a fixed structure, so it can be compared, audited and cited in an assurance case.

The example opposite is illustrative; real cards also link to the full physics record and validation report.

Data card · Example Unclassified · Illustrative values

LE-EOIR-0003 · Small craft, coastal, LWIR

Version 1.2 · Issued [date]

Sensor model
Generic uncooled LWIR, 640 × 512, 8–12 µm
Scene and targets
Six generic small-craft classes; coastal backgrounds
Environment
Diurnal cycle; sea state 0–4; clear to light haze
Physics models
Thermal balance for targets and sea surface; atmospheric transmission; sensor noise
Labels
Boxes, instance masks, class, range, aspect angle
Validation
Train-on-synthetic, test-on-real: [result] · Separability: [result] · Measured reference: [dataset]
Intended use
Detector pre-training and robustness testing
Out of scope
Sole basis for operational acceptance
Known limits
Not validated in fog, rain or sea state above 4
Provenance
Generator version, configuration and random seeds recorded

05 — Your obligations

Built to fit the assurance work you already do.

Test and evaluation

Synthetic test sets and coverage reports that slot into your test and evaluation planning.

Responsible AI

Documentation designed to support assessments under Defence's responsible AI guidance and comparable frameworks.

Model and system cards

Data cards that feed directly into the model and system documentation your program maintains.

Need evidence for an assurance case? Talk to us about your model, your data and your obligations.

Request a briefing