When the grid fails — through storm damage, cyberattack, equipment cascade or conflict — national emergency managers are often flying blind. Ground-reporting networks go silent precisely when they are needed most, and utility SCADA telemetry is either compromised or inaccessible outside the operator's own walls. Satellite-based nighttime light detection fills that gap: a low-Earth orbit radiometer passes over a blacked-out city and registers the absence of light against a calibrated baseline, flagging the outage boundary within one to two hours of the event.
The satellite stack combines a high-sensitivity panchromatic low-light imager — capable of resolving light levels down to 10⁻⁹ W cm⁻² sr⁻¹ µm⁻¹ — with repeat-pass tasking across a multi-satellite constellation. Change detection against a pre-built nocturnal baseline atlas isolates outage polygons at roughly 500-metre spatial resolution. Ancillary RF survey payloads can corroborate by detecting the collapse of LTE and FM broadcast signals in the same area, adding a second independent indicator.
The operational payoff is concrete: emergency coordinators receive a georeferenced outage map before any utility company has finished its manual fault assessment. That map drives generator pre-positioning, hospital triage prioritisation and restoration crew routing. For a government managing a major disaster, knowing which districts lost power — and in what sequence — is the difference between a coordinated response and an improvised one. No commercial provider will guarantee delivery of this data during the exact crisis when a foreign government's export controls or commercial priorities may intervene.
Frequently asked
How exactly does a satellite detect a power outage — what physical signal does it measure?
The primary method is night-light radiance change: sensors like NASA/NOAA's VIIRS Day/Night Band measure emitted visible and near-infrared light at night. When a neighbourhood blacks out, its radiance drops sharply relative to baseline composites. A secondary method uses thermal IR to detect the cooling of substations and industrial heat sources that lose power. Neither signal is unambiguous on its own; algorithms cross-validate both, plus ancillary wind and precipitation data, to reduce false positives.
Why should our government own these satellites rather than subscribe to a commercial data feed?
During a major national emergency — the exact moment outage data is most valuable — commercial vendors face competing demand from multiple clients, export-control scrutiny may freeze data transfers, and pricing can spike under emergency clauses. A sovereign constellation tasked by a national grid operator delivers data on the operator's priority timeline, with no third-party access to the intelligence, and at a predictable lifecycle cost. The World Bank's 2022 resilience financing framework explicitly flags dependency on single commercial providers as a fiscal risk for lower-middle-income economies.
Which orbit and sensor type give the best performance for this application?
A LEO sun-synchronous orbit at 500–550 km altitude optimises the trade-off between ground resolution and swath width. A constellation of 12–20 microsatellites in this orbital shell can achieve sub-2-hour revisit over any point on Earth. For the night-light channel, a low-noise CMOS or CCD detector equivalent to VIIRS DNB performance is sufficient; a secondary thermal IR band (8–14 µm) adds daytime and cloud-edge capability.
Can synthetic aperture radar (SAR) replace optical night-light sensors for outage detection?
SAR cannot directly measure light emission, so it cannot replace night-light sensors for the primary detection task. However, SAR is cloud-penetrating and works day or night, making it an important complement: it can detect physical damage to transmission towers and substations through coherence-change interferometry (InSAR), which strongly correlates with outage cause. Operators like ICEYE and Capella Space have demonstrated this approach after Hurricanes Ida and Ian. The best architecture fuses both modalities.
How quickly can the system confirm an outage after it occurs?
With a 16-satellite LEO constellation, the maximum wait for the next pass over any given point is roughly 90 minutes. Add 20–40 minutes for downlink, processing, and automated change-detection, and a confirmed outage map can reach grid operators within two hours of the event. This compares favourably to the 18–36-hour field-survey timelines documented by the US DOE after Hurricane Ian.
What resolution is actually needed — do we need expensive very-high-resolution satellites?
No. Sub-district or census-tract level outage mapping, which is what emergency managers need for resource dispatch, requires roughly 100–300 m spatial resolution. VIIRS DNB achieves 742 m and has proven operationally useful. Higher resolution (sub-100 m) is useful for individual substation monitoring but increases cost and data volume significantly. A tiered architecture — wide-area night-light at moderate resolution plus targeted high-resolution thermal IR tasking for confirmed outage zones — is the most cost-effective sovereign design.
How does this integrate with existing utility SCADA and smart-meter systems?
Satellite-derived outage maps are intended to complement, not replace, utility telemetry. SCADA systems have near-real-time point data but require functioning communications infrastructure that itself may be damaged. Smart-meter outage notifications depend on cellular or RF mesh networks that can fail simultaneously with the grid. The satellite layer provides an independent, communications-agnostic verification of outage extent that grid operators can use to validate or correct SCADA-based damage estimates, particularly at the distribution level where SCADA coverage is sparsest.
Is this technology mature enough to procure today, or are we buying a promise?
The technology is live and operational. NOAA's VIIRS-based outage detection has been used routinely since 2012; NASA's Black Marble product suite is freely accessible. Commercial providers including Planet and Satellogic offer contracted outage-detection products. What a sovereign programme adds is guaranteed priority access, classified grid-infrastructure overlays, and the ability to task sensors on national schedules rather than vendor schedules. Procurement risk is low; the integration and policy-framework work is where complexity lies.