Eyes in the sky: How Isro's EOS-09 will see through storms, smoke and silence

India Today

17-05-2025

It was the horror of the 2008 Mumbai terror attacks that jolted India into action, pushing the country's space agency to fast-track the launch of a satellite built not just for the skies—but for national security. In less than a year, RISAT-2 was launched, drawing heavily from Israel's TecSAR-1 and signalling the dawn of India's homegrown Radar Imaging Satellite (RISAT) series.advertisementRISAT satellites come in two flavours: X-band and C-band Synthetic Aperture Radar (SAR) systems. While X-band SAR—used in RISAT-2 and its successors—offers razor-sharp, high-resolution imaging for military surveillance and target detection, the C-band variant—pioneered by RISAT-1—is tailored for broader Earth observation, cutting through clouds and darkness to monitor terrain, vegetation, and water bodies.Now, nearly two decades later, that legacy evolves into its next chapter with EOS-09 (RISAT-1B), scheduled for launch on May 18, 2025, coincidently days after a major escalation between Indian and Pakistan following the deadly Pahalgam terror attacks.Watch this incredible timelapse of PSLV-C61 / EOS-09 as it rolls from the Payload Integration Facility (PIF) to the Mobile Service Tower (MST) at SDSC-SHAR, Sriharikota — a crucial step in #ISRO's 101st launch mission.Each frame captures the precision, teamwork & engineering pic.twitter.com/KjAm7ncVee— Dr Jitendra Singh (@DrJitendraSingh) May 16, 2025advertisementRebranded under the Earth Observation Satellite (EOS) umbrella, the new satellite represents ISRO's latest leap in all-weather, day-and-night imaging capabilities.Armed with upgraded C-band SAR, EOS-09 is designed for real-time applications like flood mapping, cyclone tracking, landslide detection, and coastal security.EOS-09 carries forward the configuration while packing enhanced radar tech and imaging versatility. With five imaging modes—including High-Resolution Spotlight and Medium Resolution ScanSAR—it offers everything from ultra-detailed surveillance (up to 1-meter resolution) to wide-area environmental monitoring.
What sets EOS-09 apart is its all-weather, day-and-night imaging capability. (Photo: Isro)
WHY EOS-09 IS DIFFERENTWhen clouds gather, storms rage, or night falls, most satellites go blind. Not this satellite equipped with C-band SAR.C-band Synthetic Aperture Radar sees through what optical satellites cannot—clouds, rain, fog, and dust—delivering uninterrupted, all-weather, day-and-night surveillance.For a country like India, where natural disasters and security threats collide across a vast and varied landscape, that's not just useful—it's indispensable.With resolutions reaching up to 1 meter, C-band SAR can detect subtle ground changes, such as vehicle movements or soil disturbances, often critical indicators of military operations or terror activity.
The satellite is scheduled for launch on May 18, 2025. (Photo: Isro)
Its ability to scan wide swath widths—ranging from 10 to 225 km—makes it uniquely suited for both large-scale disaster mapping (think floods, cyclones, landslides) and fine-grained reconnaissance.But EOS-09's SAR system isn't just powerful—it's smart. It's expected to support co- and cross-polarisation, and possibly hybrid polarimetry, enabling it to classify terrain, vegetation, and even man-made structures like tents or hidden camps.This dual-use capability strengthens national security while aiding agriculture, forestry, hydrology, and urban planning.At sea, the C-band SAR becomes a silent guardian—monitoring illegal maritime activity, tracking oil spills, or pinpointing vessels along India's 7,500 km coastline.When disaster strikes, its radar slices through storm clouds to deliver real-time damage assessments, guiding emergency response and resource deployment long before the skies clear. EYE ON THE PRIZEThe launch of EOS-09 comes on the heels of the Pahalgam terror attack and Operation Sindoor, underscoring the growing urgency to enhance surveillance across India's most sensitive frontiers.advertisementWith 15,000 km of land borders—ranging from the volatile Line of Control with Pakistan to the rugged terrain along China and the increasingly porous stretches near Bangladesh—and a 7,500 km coastline, India's geographic sprawl presents complex and constant security challenges.What sets EOS-09 apart is its all-weather, day-and-night imaging capability, making it a reliable sentinel in situations where traditional optical satellites falter. Whether tracking suspicious movement along the LOC or monitoring cyclones brewing in the Bay of Bengal, it delivers uninterrupted intelligence, when it's needed most. EOS-09 is a critical step forward, but it also signals the need for a larger, more coordinated satellite constellation—one capable of watching over every ridge, river, and coastline with unwavering precision.This smart, adaptable radar system transforms EOS-09 into a true all-weather eye in the sky, ready to respond to India's diverse surveillance and disaster response needs.In the crucible of Operation Sindoor, India demonstrated that speed, strategy, and technology can decisively alter the outcome of high-stakes confrontations.Precision targeting and swift neutralisation of threats weren't just about boots on the ground—they were powered by eyes in the sky.Satellites like EOS-09 embody this fusion of vigilance and innovation, enabling round-the-clock surveillance that sees through darkness, cloud, and chaos.advertisementAs India confronts evolving security challenges, it's this seamless blend of real-time intelligence and rapid response that continues to fortify the nation's defences with unmatched technological edge.