Maritime domain awareness missions

Coastal radar sees to the horizon. Space-based AIS, RF and SAR see the whole EEZ, including vessels that have gone deliberately dark.

The dependence this ends: Coastal radar horizons and third-party vessel data

The gap your coastal radar cannot close

A coastal radar installation sees perhaps 40 nautical miles on a clear day. An exclusive economic zone extends 200. That gap is not a technical inconvenience; it is where illegal fishing fleets operate, where sanctioned tankers conduct ship-to-ship transfers, and where fast craft move cargo that no manifest will ever describe. Filling it with patrol vessels is expensive and, at scale, impossible.

Until recently, most governments filled the gap with purchased vessel-tracking data from commercial AIS aggregators. That arrangement has two structural problems. First, the data is compiled from receivers operated by foreign companies under foreign law, and it can be withheld, degraded or re-sold to third parties without your knowledge. Second, AIS is cooperative: a vessel that turns off its transponder simply disappears from the feed. The 2022 period made both problems visible simultaneously, as commercial data providers began applying their own geofencing rules over contested maritime zones. Sovereign MDA means you do not depend on another government's vendor to tell you what is happening in your own waters.

Why three sensor types, not one

No single sensor closes the picture. Space-based AIS receivers collect transponder broadcasts from vessels across a wide swath on each pass, giving you cooperative traffic. That is useful baseline data, but it is precisely the vessels absent from that baseline that matter most. RF signal-mapping payloads detect the radio emissions that working vessels produce regardless of whether their AIS is active: radar altimeters, communication uplinks, engine-management telemetry. A vessel running dark still radiates. Correlating an RF contact with no corresponding AIS return is the first flag.

Synthetic aperture radar closes the loop. C-band SAR produces high-resolution imagery through cloud and at night, resolving vessel silhouettes to lengths accurate within a few metres at typical small-satellite resolutions. A 10-metre vessel detected by RF but absent from AIS can be imaged on the next SAR pass and its hull geometry compared against known vessel profiles. The three layers together produce a detection chain that a vessel operator cannot defeat by switching off a single system. Each layer has honest limits: AIS suffers message collision in very dense traffic; RF attribution requires a library of known emitter signatures; SAR revisit over a specific point from a small constellation may be measured in hours, not minutes. The architecture is designed so that the weakest link in any one layer is covered by the others.

Sizing the programme to an EEZ, not an ocean

The ambition ladder here has three genuine rungs, and the right entry point depends on the size of the EEZ, the density of traffic and what the government already operates.

A pathfinder mission, typically one to three 6U CubeSats carrying AIS receivers, establishes national space infrastructure, trains the first operator cohort and produces real contact data within 18 to 30 months of contract signature. Missions of this class have publicly reported budgets in the low tens of millions of dollars. The revisit is limited and the RF and SAR layers are absent, but the programme exists, the spectrum is filed, the ground station is yours and the data never transits a foreign server.

An operational constellation adds RF-mapping payloads and a C-band SAR asset, bringing the total to perhaps four to eight satellites depending on orbital phasing and EEZ geometry. Revisit over any point in the zone drops to the low single-digit hours. This is where dark-vessel detection becomes operationally credible rather than demonstrative. Constellation programmes of this scope, drawing on published figures from comparable national initiatives, sit in the mid-to-upper tens of millions of dollars range across a four-to-six-year delivery arc.

A full sovereign programme adds in-country processing infrastructure, a national mission-control centre, a trained permanent operations team and the legal and technical architecture to classify and distribute products to naval, coastguard and customs users under national authority. The satellite count, ground architecture and budget at this level are specific to each nation's EEZ geometry and threat model; no single public precedent maps cleanly onto every buyer. What is consistent across all three rungs is the ownership structure: source-access terms, hardware audit rights and staged handover to national teams are agreed before signature.

What you own at handover

At programme completion the customer holds the satellites and their ground segment outright, not a data subscription. The ground station hardware is in-country. The mission-control software is delivered with source access under terms agreed at contract signature. The trained operator team is yours; they have run the constellation through at least one full anomaly cycle before handover is declared complete.

The limits of the capability are worth stating plainly. A small-to-medium sovereign constellation will not match the revisit of a commercial constellation with dozens of assets. SAR resolution from a small-satellite platform is sufficient for vessel detection and gross classification but will not resolve deck equipment or crew. RF attribution accuracy depends on the quality of the emitter library built during operations. Cloud cover does not defeat SAR, but orbital geometry means there will be windows of reduced coverage over any fixed point. These are engineering realities, not programme failures. A well-designed MDA architecture accounts for them in the sensor-fusion logic rather than pretending they do not exist.

The sensor-fusion architecture on the ground

The satellites produce raw data. The value is in what happens to it in-country. In-country processing infrastructure means the correlation engine, the dark-vessel flagging logic and the contact database all run on hardware under national jurisdiction. No contact report leaves the country before a national analyst has seen it. That matters for intelligence-law reasons and for operational security.

The processing pipeline ingests AIS contact lists, RF detections and SAR image chips, runs correlation against the vessel registry and historical track database, and surfaces anomalies for human review. Vessels with no AIS return but a confirmed RF and SAR contact are flagged automatically. Vessels whose AIS-reported position disagrees with their SAR-imaged position, a known spoofing signature, are flagged separately. The output is a recognised maritime picture that is owned, classified and distributed entirely within national systems. Integration with existing coastal radar feeds and patrol-vessel reporting is straightforward at the data layer; the space segment adds coverage beyond the radar horizon rather than replacing what is already working.

What this mission is built from

Space-based AIS receivers: Collects cooperative vessel transponder broadcasts across the EEZ on each orbital pass, forming the baseline contact list against which dark vessels are identified by absence.
RF signal-mapping payloads: Detects radio emissions from vessels running without AIS, providing the primary detection layer for deliberately dark contacts.
C-band SAR payloads: Produces cloud-penetrating, day-night radar imagery to confirm vessel presence, measure hull length and support classification of flagged contacts.
6U CubeSat platforms: Provides the small-satellite platform for pathfinder and early constellation phases, keeping launch mass and cost within reach of a single-nation programme.
Inclined low Earth orbits: Delivers the orbital geometry needed for repeated, predictable passes over an EEZ at mid or low latitudes with acceptable revisit intervals.
In-country data processing: Runs the sensor-fusion engine, dark-vessel flagging logic and recognised maritime picture entirely within national jurisdiction, with no dependency on foreign cloud infrastructure.

What you end up owning

Satellites and their subsystems, with full hardware audit rights exercised during build
In-country ground station and mission-control infrastructure, physically located on national territory
Mission-control and data-processing software delivered with source access under terms fixed at contract signature
Spectrum filings and orbital slot registrations held in the customer nation's name with the ITU
Trained national operator and analyst team, qualified through live operations before handover
The recognised maritime picture database and all contact history accumulated during operations
Contractual right to independent maintenance and upgrade without returning to Satellize

Handover is staged: the national team shadows operations from first light, takes primary responsibility during the constellation phase and holds sole authority by programme completion. Satellize retains no ongoing data rights and no privileged access to the ground station after handover is declared. Launch and integration partners involved in specific bus platforms or launch vehicles remain bound by the confidentiality and audit terms negotiated at programme outset.

Programme parameters

Pathfinder satellite count	1 to 3 satellites (AIS payload primary)
Operational constellation satellite count	4 to 8 satellites (AIS, RF and SAR payloads distributed across the constellation)
Target orbit	Inclined LEO, 450 to 600 km altitude, inclination matched to EEZ latitude band
Revisit over EEZ (operational constellation)	Low single-digit hours at any point within the zone; geometry-dependent
SAR resolution class (small-satellite platform)	Sufficient for vessel detection and length estimation; not sub-metre deck-detail imagery
Pathfinder delivery timeline	18 to 30 months from contract signature to first operational pass
Full programme timeline	4 to 6 years from contract to sovereign handover of complete constellation and ground segment
Ground stations	Minimum one in-country primary station; second station recommended for redundancy and polar coverage
Operator team size to sustain	Typically 8 to 20 trained national staff for a constellation of this class; mission-specific
Coverage limitation	Cloud cover does not defeat SAR; orbital geometry produces coverage windows, not continuous stare

Sources

One contract, one accountable engineer

Commissioned as one programme, not a stack of contracts: spacecraft, launch, ground segment, mission control, training and handover are priced together. Source-access terms and audit rights are agreed in writing before signature. Request an EEZ coverage analysis.