What is on-board processing?
On-board processing (OBP) refers to the execution of signal processing, data handling, or computational tasks directly on the satellite, rather than simply relaying raw signals to the ground for terrestrial processing. OBP ranges from the relatively simple (digital channel switching in a communications satellite) to the complex (AI-based image analysis on an Earth observation satellite), and represents a fundamental architectural choice between 'smart satellite, dumb ground' vs. 'relay satellite, smart ground'.
OBP for communications
In communications satellites, OBP enables digital payloads that demodulate received uplink signals, route them to the appropriate downlink beam, and re-modulate for transmission — enabling flexible mesh connectivity where any user beam can communicate directly with any other beam, not just via a ground hub. This is the foundation of the digital payload architecture in systems like O3b mPOWER, Intelsat Epic+, and Starlink Gen2. OBP also enables regenerative NTN (Non-Terrestrial Network) architectures where a full 5G base station protocol stack runs on the satellite — critical for NTN with low-end devices that cannot compensate for round-trip delays to terrestrial ground stations.
OBP for Earth observation
Earth observation satellites increasingly perform onboard processing to reduce downlink bandwidth requirements: applying cloud masks (transmitting only cloud-free pixels), running change detection algorithms to flag only interesting scenes for priority downlink, and even running neural network inference on imagery to generate direct intelligence products. ESA's Φ-Sat-1 (2020) was the first ESA satellite with AI-based cloud masking running onboard. Planet Labs and Satellogic are developing onboard analytics for near-real-time edge intelligence from orbit.