Iran Blankets Region with Over-the-Horizon Radars to Thwart Surprise US, Israel Attacks
This rapid expansion of OTH radar complexes represents a cornerstone in Tehran’s broader effort to insulate itself from a potential pre-emptive strike by the United States or Israel, both of whom have escalated rhetoric over Iran’s expanding ballistic missile and nuclear programs.
(DEFENCE SECURITY ASIA) — In a clear signal of its shifting defence posture and deepening strategic anxieties, Iran is accelerating the deployment of Over-the-Horizon (OTH) radar systems across key locations, significantly enhancing its long-range surveillance and early warning capabilities.
This rapid expansion of OTH radar complexes represents a cornerstone in Tehran’s broader effort to insulate itself from a potential pre-emptive strike by the United States or Israel, both of whom have escalated rhetoric over Iran’s expanding ballistic missile and nuclear programs.
Unlike traditional radar systems constrained by the Earth’s curvature, OTH radar employs high-frequency waves that bounce off the ionosphere, allowing it to detect and track aircraft, missiles, and maritime targets at distances exceeding 3,000 kilometers.
In late March, Iran activated its ninth Ghadir-class OTH radar installation, a high-powered system capable of detecting targets up to 1,100 kilometers away, solidifying its role as a vital node in Iran’s integrated air defence network.
This activation not only boosts Iran’s ability to detect low-observable aircraft and incoming ballistic missiles but also enhances its readiness in the face of stealth-centric platforms such as the American F-35 and Israeli F-15I Ra’am.
Open-source intelligence suggests that Iran has constructed two Ghadir radars in the strategic south, with coverage designed to blanket the Persian Gulf and the Strait of Hormuz — maritime arteries vital to global oil shipments and historically volatile flashpoints.
Iran’s OTH Radar
Control over these chokepoints grants Iran an asymmetric strategic edge, enabling it to monitor Western naval movements and potentially complicate U.S. Carrier Strike Group operations in the event of conflict.
Further north, another Ghadir radar site has been completed near the city of Tabriz, reportedly close to a subterranean ballistic missile base — a probable target for any future air campaign by Israel or the United States.
The positioning of this radar near critical missile infrastructure reflects Tehran’s emphasis on survivability and layered defence against precision-guided munition strikes and cyber-electronic warfare.
In a separate development, Iran is reportedly finalising a new and more sophisticated OTH radar variant near Shiraz, featuring a taller array structure and enhanced antenna density for improved signal capture and resistance to jamming.
This next-generation radar, under evaluation since 2022, is expected to offer superior tracking accuracy against fast-moving targets such as hypersonic missiles — a domain in which regional rivals are investing heavily.
Over-the-Horizon (OTH) radar represents one of the most transformative advancements in long-range surveillance technology, enabling the detection and tracking of airborne and maritime threats at distances spanning thousands of kilometers—far exceeding the line-of-sight limitations inherent to conventional radar systems.
Iran’s OTH Radar
Unlike standard radar arrays, which are constrained by the Earth’s curvature and limited to detecting targets within visual range, OTH radar systems employ high-frequency radio waves that refract off the ionosphere, granting operators the extraordinary ability to monitor vast swathes of territory that would otherwise remain invisible.
This ionospheric bounce technique effectively turns the upper atmosphere into a strategic sensor layer, allowing defence planners to project early-warning coverage deep into adversary-held airspace or contested maritime zones.
The strategic implications of this capability are profound, particularly for nations situated near volatile borders or critical maritime chokepoints, where the ability to detect a threat several minutes or hours earlier can determine the outcome of a conflict before the first missile is launched.
Modern OTH radar systems boast a maximum detection envelope of up to 3,000 kilometers, depending on technical configuration and atmospheric conditions—sufficient to monitor activity across entire regions, from carrier battle groups at sea to long-range bomber formations and intercontinental ballistic missile launches.
At the heart of their value lies the ability to provide early warning against an array of high-priority threats—ranging from hypersonic glide vehicles and stealth-capable bombers, to ballistic and cruise missile launches and adversary naval surface groups operating near strategic sea lanes.
In an age where advanced airframes like the B-21 Raider and F-35 Lightning II are designed with radar-evading profiles, OTH radar provides an asymmetric means of detection, leveraging waveform diversity and high-frequency reflection to unmask even the most elusive aerial platforms.
Equally critical is the role OTH systems play in monitoring strategic maritime arteries—such as the Strait of Hormuz, Bab el-Mandeb, or the South China Sea—where geopolitical tensions and great-power competition converge with potential flashpoints.
In January, Iran deployed the Nazir OTH radar atop the highlands of Gilan Province, expanding its surveillance umbrella over the Caucasus and eastern Türkiye — areas that have gained new strategic relevance due to evolving alignments.
Capable of detecting aerial targets up to 800 kilometers away, the Nazir radar provides a vital monitoring platform aimed at Azerbaijan, whose growing defence ties with Israel and Türkiye have raised alarms in Tehran.
Persistent claims suggest that Israel may have previously leveraged Azerbaijani airspace to conduct reconnaissance and even execute limited strikes on Iranian military facilities, including advanced air defence and nuclear-related sites.
Iran’s bolstering of radar assets in this direction signals a recalibration of threat perception, particularly as Baku continues to deepen security cooperation with NATO-aligned partners.
OTH radar’s resilience lies in its technical architecture — operating on multiple frequencies with the ability to frequency-hop, making it highly resistant to detection and disruption by hostile electronic warfare systems.
Satellite image of Iran’s OTH radar complex
First unveiled in 2015 and operational by 2016, Iran’s OTH radar program has grown from an experimental capability into a strategic surveillance backbone, supported by domestic research and development under sanctions pressure.
Brigadier General Farzad Esmayeeli, then-Commander of Iran’s Khatam al-Anbia Air Defence Base, affirmed in 2016 that, “Sistem radar OTH telah mula beroperasi dan mulai sekarang, tiada objek penerbangan yang sukar dikesan radar boleh memasuki ruang udara Iran tanpa kebenaran.”
He further added, “This radar system is specifically designed to detect small aerial objects, including aircraft such as the MQ-1, RQ-4, and U-2. It is also capable of effectively detecting and tracking both ballistic and cruise missiles, and most importantly, stealth aircraft that are typically difficult to detect by conventional radar.”
PressTV reports that many of Iran’s OTH systems have been installed in mountainous regions such as southeastern Iran, at altitudes exceeding 3,000 meters to maximise line-of-sight extension and boost detection range.
Domestically built and tailored for Iran’s unique threat environment, these radars are designed to endure sophisticated electronic jamming and to detect even low radar cross-section (RCS) targets such as unmanned aerial vehicles and stealth missiles.
Their deployment marks a key element in Iran’s asymmetric defence doctrine — blending legacy capabilities with indigenous innovation to offset technological disadvantages vis-à-vis Western powers.
With tensions simmering in the Gulf and broader Middle East, Iran’s expanding radar network could complicate adversarial planning and serve as a potent psychological and operational deterrent against pre-emptive strikes.
The strategic geography of Iran — flanked by rival states, active conflict zones, and critical maritime corridors — makes the role of long-range early warning systems more essential than ever in safeguarding national airspace and projecting military resilience.