CCTV surveillance design with DORI coverage calculations
Coverage is an engineering result, not a guess. Every camera is placed against an identification, recognition or detection requirement, with the lens, mounting height and pixel density calculated to prove it.
In short
CCTV & Surveillance Design — Camera placement, lens and DORI calculations, coverage plans, storage sizing and network design for CCTV systems of any scale.
Service overview
CCTV only performs when the camera, lens, mounting height, lighting and scene geometry are engineered against a stated task. We design to defined observation categories — monitor, detect, observe, recognise, identify — so every camera on the layout has a purpose and a verifiable pixel density.
Coverage is modelled in plan and 3D, checked against obstructions, glare, backlighting and vegetation growth, then documented with field-of-view cones, mounting details and cable schedules that an installer can build from without interpretation.
Recording, retention, bandwidth and storage are sized alongside the camera count, including analytics load, redundancy and evidential export workflow, so the operational system matches the design intent on day one.
What this service covers
DORI calculations
Pixel-density targets per zone with lens and range verification.
Coverage plans
Field-of-view drawings showing overlaps, blind spots and priorities.
Storage sizing
Bitrate, retention and redundancy calculated, not estimated.
Network design
Switch, PoE budget, VLAN and bandwidth architecture for video.
Key capabilities
- Task-based camera selection and pixel-density verification (DORI)
- Field-of-view modelling in plan, section and 3D with obstruction checks
- Low-light, thermal, ANPR/LPR and long-range PTZ scheme design
- Bandwidth, storage, retention and redundancy calculation
- Video analytics selection and false-alarm management strategy
- External lighting coordination for reliable night-time performance
Designed to be verified
Each camera carries a stated purpose, target pixel density, lens, mounting height and cable route. Commissioning teams can verify the installed system against the design rather than opinion.
Deliverables
- Camera schedule with purpose and DORI targets
- Field-of-view coverage drawings per floor or zone
- Storage and bandwidth calculation sheet
- Network and PoE architecture drawings
- Vendor-neutral technical specification
- Camera layout drawings with numbered field-of-view cones per level
- Camera schedule with model, lens, mounting height and observation category
- Storage, bandwidth and retention calculation sheet
Typical environments
Frequently asked questions
What is DORI?
DORI defines pixel density needed for detection, observation, recognition and identification. It converts vague coverage requests into a measurable design target.
Can you work from AutoCAD backgrounds?
Yes. Architectural DWG backgrounds are the normal starting point; we return layered security drawings against them.
Do you specify camera brands?
We specify performance. If you have a preferred vendor list, we map the specification to compliant models.
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