What can a satellite actually tell us that a survey ship cannot?

Satellites provide near-real-time, wide-area context that no single ship can match economically: vessel-traffic density (via AIS), sea-surface current and wave climatology, surface-roughness proxies for near-shore seabed morphology, and persistent change detection over suspected anchor-drag corridors. They don't replace the ship's multibeam sonar for final engineering design, but they drastically reduce the area that ship needs to cover, cutting survey costs by up to 40% according to GEBCO analyses.

Why should our government own the satellites rather than simply buying data from Planet or Spire?

A sovereign constellation gives your government uninterrupted, unredacted access to imagery and AIS data regardless of export-control status, sanctions regimes, or commercial disputes. It also lets you task assets on demand — surveying a contested EEZ, monitoring a rival's cable-laying activity, or verifying a fault location without a third party knowing you looked. Renting data from commercial vendors means accepting their collection priorities, licensing terms, and the risk of service interruption at the worst possible moment.

How many satellites would a small island nation realistically need for this mission?

A minimum viable constellation for persistent maritime domain awareness and bathymetric change detection is approximately 6–12 microsatellites (50–150 kg class) in a sun-synchronous LEO at 500–550 km altitude. This delivers daily revisit over a nation's EEZ and near-real-time AIS. Hyperspectral or SAR payloads can be hosted on the same bus to add shallow-water bathymetry capability. Several nations have launched comparable constellations for under $150 million total including ground infrastructure.

What international permissions do we need before using satellite data to plan a cable route through another nation's EEZ?

Remote sensing from space is lawful under the 1986 UN Principles Relating to Remote Sensing of the Earth from Outer Space (UNGA Res. 41/65), which does not require prior consent from the sensed state. However, any physical survey vessel operating in a foreign EEZ requires that nation's permission under UNCLOS Article 246. The satellite data can be gathered freely; the ground-truth ship survey requires diplomatic clearance.

How accurate is satellite-derived bathymetry compared to IHO S-44 standards?

Current satellite altimetry products (e.g. GEBCO 2024 grid) achieve depth accuracies of ±50–200 m in deep water — far below the IHO S-44 Order 1a standard of ±0.5% of depth required for cable engineering. Satellite optical-derived bathymetry in clear, shallow water (under ~20 m) can approach ±1 m accuracy, which is borderline Order 2. Satellite data therefore qualifies as reconnaissance-grade route screening, not as the certified hydrographic survey required for final route approval.

Can we use satellite AIS to identify which fishing fleets pose the greatest trawl risk to our proposed cable route?

Yes. Satellite AIS combined with vessel behavioural analytics (available from providers like Spire or HawkEye 360, or from a sovereign constellation) can classify fishing vessels by gear type, identify repeated trawl-track corridors, and flag high-risk overlap zones with proposed cable alignments. This analysis directly informs burial-depth requirements and protected-zone boundaries, and is now standard practice for major cable system environmental impact assessments.

What happens to our cable route data sovereignty once we share it with an international consortium?

Cable consortia typically require all route survey data to be deposited in a shared project database accessible to all consortium members and their governments. Once shared, your nation loses unilateral control over that data. Owning the upstream satellite collection means you retain the raw intelligence and share only what is contractually necessary, preserving leverage in renegotiation, fault-repair disputes, and future expansion decisions.

Is there a global database we can use as a starting point before committing to a satellite programme?

Yes. GEBCO (General Bathymetric Chart of the Oceans), maintained jointly by IHO and IOC-UNESCO, provides free global bathymetric grids at 15 arc-second resolution. The TeleGeography Submarine Cable Map shows existing cable routes and landing stations. NOAA's National Centers for Environmental Information host global ocean current and wave climatology datasets. These public resources are excellent for initial corridor screening but must be supplemented by higher-resolution satellite tasking and ultimately ship surveys before a route is committed.

4.9.1Live

Subsea Cable Route Planning

Workers on a ship deck handling thick orange submarine cable near a tropical shoreline — A woman gazes at the ocean whose seafloor cable routes are now mapped with precision using satellite data.

Satellite Data Guides Subsea Cable Route Planning

1
Observation satellites
Radar altimetry maps seafloor bathymetry
2
Ground station downlink
Raw swath data received at coastal hub
3
Route-risk analytics
Hazard layers: slopes, seismicity, fishing zones
4
Cable planners
Optimal corridor chosen, survey ship dispatched

Satellite-derived bathymetry and hazard data flow through ground processing to deliver safe, optimised cable corridors for engineers.

Page in the build queue

This application has its place in the atlas. The full page — short and long descriptions, what-matters bullets, sovereignty rationale, and the eight-field architecture block — is being written next.

Maturity reading: Operational systems exist with paying customers. Phase 1 built §4.1 (Maritime Intelligence) end-to-end as the depth-and-format reference. Section 4 is the next section to graduate from scaffold to full content; the rest follow on the roadmap.

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4.9.2 · Next

Subsea Cable Fault Localisation

Bring this into your sovereign programme.

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