We're buying radars that see the "invisible." This is a game changer for the Polish army.

• Poland has purchased 28 passive location radars. The order can be expanded to 46 radars under an option, totaling PLN 5.8 billion gross.
• This very important purchase will enable the creation of an effective multi-layered anti-aircraft defense.
• Polish-made radars are modern equipment that can detect even difficult-to-detect targets.

The war in Ukraine has demonstrated that modern air defense is an absolutely crucial capability today. In this respect, it is equally important to have the means to detect and shoot down the center of an air attack. Poland has ordered crucial radar systems. On Tuesday, September 2, 2025, during the 33rd International Defense Industry Exhibition in Kielce, an executive agreement for the supply of passive location radars (PLOs) was signed .

The order is divided into a guaranteed and an optional portion. Under the guaranteed portion of the order, the military will receive 28 RPLs (four radars per set, for a total of seven sets known as the passive location system (SPL)) for PLN 3.9 billion gross. The optional portion of the order is for 18 radars for PLN 1.9 billion gross. This amounts to a total of 46 radars for PLN 5.8 billion gross.

This is one of the largest contracts for the Polish arms industry. The contract will be implemented by the PGZ-NAREW consortium, which includes the Polish Armaments Group, Huta Stalowa Wola, Jelcz, Mesko, the Maritime Technology Research and Development Center, PCO, PIT-RADWAR, Military Communication Works No. 1, Military Armament Works, Military Electronic Works, and Tarnów Mechanical Works.

However, the delivery timeline may be shocking. These are scheduled for 2030-2038. This means that it will take five years for the first units to arrive, and 13 years before all deliveries are completed .

The sheer number also raises some doubts. The Technical Modernization Plan for 2021-2035 calls for the purchase of as many as 63 sets. Each contains four radars, so that's 252 units. This seems like a "large" option, and it was hard to expect such a large order, but a mere 11 sets may prove insufficient.

However, given the high price of the order, approximately PLN 0.5 billion per set, purchasing more than 60 sets would entail a huge cost . Even with a reduction in the unit price, it is unlikely that the final value of such an order will be less than PLN 20 billion.

Considering the financial realities, the size of the contract seems quite reasonable. If additional funds can be secured in the coming years, it is possible to expand the order. Although the passive tracking systems were ordered under the Narew program, they will also operate on Wisła, i.e., the Patriots purchased by Poland.

Polish Integrated Multi-Layered Air Defense, or Why Do We Need SPL?

To fully understand the role passive location systems will play in air defense, it's worth familiarizing yourself with the current structure of the Air Force. The war in Ukraine demonstrated what experts have long been saying: Poland needs a multi-layered air defense system. Countering various air attack assets (AATs) requires the use of multiple types of effectors and sensors.

Poland will have eight Patriot batteries, acquired under the Wisła program . Each battery will be equipped with two state-of-the-art American GhostEye radars (one per firing unit). This highly efficient fire control radar will be used to guide anti-aircraft missiles. This high quality is also reflected in its high price. The Polish Patriots will be equipped with two types of missiles.

These will be the very expensive PAC-3MSE and a cheaper complement. It appears that the PAC-2 GEM-T will serve as the cheaper effector for some time. Eventually, they will be replaced by the as-yet-defunct CAMM-MR missiles.

The PAC-3MSE is intended to counter hypersonic missiles and ballistic missile components. Simply put, these are highly demanding targets. A cheaper addition will engage targets at long range that can be taken down at a lower cost.

The basis of the Polish air defense system, however, will not be the Patriot, but systems purchased under the Narew program . A total of 23 batteries (2 missiles each, for a total of 46 missiles) will be used. The missiles will be guided by Sajna fire control radars (not yet ordered). The effectors will be existing CAMM-ER (extended range) missiles. They will be cheaper than CAMM-MR and PAC-3MSE. The cost will also be accompanied by limited capabilities. Therefore, the system will be ideally suited to countering waves of cruise missiles, which are relatively easy to intercept.

We also have the Pilica+ system , which will protect the Wisła battery and airfields in Poland. We have purchased 22 of these systems. Each is equipped with six Jelcz vehicles with dual 23mm guns and Grom/Piorun missiles, as well as two iLauncher launchers with CAMM missiles. Each battery will be equipped with the Polish Bystra radar.

The system is complemented by P-18PL early detection radars, ordered in 2023. The specific nature of this equipment means it can detect targets from hundreds of kilometers away, but with very low accuracy. It is therefore ideal for warning of an attack, although more accurate but shorter-range radios are involved in repelling it.

Completely covering an area with ground-based radio stations is an extremely difficult task. First, it requires a large number of sets. Each such set would have to operate around the clock, which would facilitate its detection (and therefore destruction) by the enemy. In peacetime, the aerostats (simply put, large balloons with attached radars), ordered in mid-2024, could prove to be an excellent solution. In times of war, early warning aircraft prove very useful. They are more difficult to shoot down than stationary aerostats, but also more expensive to operate. We currently have two such aircraft.

Gaps in anti-aircraft capabilities

This is a very simplified picture of air defense. It doesn't include, for example, the Miecznik ships, which will protect us from the Baltic Sea (which could become a "highway" for Russian cruise missiles). However, we can point out several gaps in such a shield. We lack effectors that could counter ballistic missile attacks (with the PAC-3MSE, we can only counter SRBMs, i.e., short-range ballistic missiles), anti-drone protection, and organic protection for mechanized and armored units.

While countering ballistic missiles is a capability that Poland should not treat as a priority today (due to the high cost and limited threat), experts have been talking about expanding universal anti-drone and organic defense for the Land Forces for a long time.

Let's return, however, not to combating such objects, but to detecting them. We need devices that can maintain 24/7 surveillance, detect difficult-to-detect objects, and avoid being exposed to fire upon detection. While this sounds like requirements for the Death Star, it turns out that all of them are met by passive location systems. Each such system consists of four passive location radars. Each such radar combines two interesting systems: PET (Passive Emitter Tracking) and PCL (Passive Coherent Location).

Passive Location System, or Catch Me If You Can

The PET system's purpose is to gather information from the environment. Every aircraft must emit different wavelengths. This applies even to the F-22, B-21, and Su-57. The SPL takes advantage of this and has the ability to collect "noise" from the environment. The PET system comprises a number of subsystems:

• COMINT - detects and analyzes signals from communication systems . Without such communication, communication between pilots and other aircraft or between unmanned aircraft and their operators is impossible;
• ELINT - detects and analyzes signals emitted by radar stations installed on board ; without its own radar, the aircraft would be "blind and deaf";
• IFF - detects and analyzes the signals of transponders and IFF systems integrators ; if the aircraft did not emit such signals, it could be shot down by its own anti-aircraft defenses;
• NAV - detects and analyzes navigation signals ; without the emission of such signals, the aircraft would have difficulty in determining its position precisely (although modern missiles are now equipped with passive navigation systems - e.g. based on a terrain map).

Even the most advanced aircraft must therefore make noise. Thanks to PET technology, we can detect such aircraft based on these emissions. The PCL system is equally interesting. It relies on emissions emitted daily by civilian devices. We can distinguish three main subsystems:

• GSM - detects and analyzes signals generated by mobile phone transmitters ;
• DVB-T - detects and analyzes signals generated by digital television transmitters ;
• FM - detects and analyzes signals generated by radio transmitters .

The wave emitted by a television transmitter reflects off a given object. This fact can be used to determine its location. To do this, we simply need to know the emitter's location (e.g., a television antenna) and at least four passive radars using PCL technology. Why four? The laws of physics dictate that three are needed to determine precise positioning along three axes. The fourth is used for increased precision.

It's worth noting that stealth aircraft are designed to be optimized for a specific wavelength and angle of incidence. This means that the use of "civilian" transmitters on board can make such a plane easy to detect. The range of the PCL subsystem is estimated at up to 150 km (although this depends on the emission source) and allows tracking of up to 120 targets. In the case of the PET subsystem, the detection distance depends on the strength of the target's signal .

But that's not all. The passive tracking system is unique because it combines the PCL and PET subsystems in a single device. This fusion significantly increases the chances of detecting an enemy missile, unmanned aerial vehicle, or aircraft.

Passive radio stations do not emit their own wavelengths, making them very difficult to detect. This allows them to operate 24/7, ensuring constant and complete surveillance of public spaces.

It is precisely these unique features of this system that make it so important. The September 2nd agreement can therefore be considered a milestone in building Poland's modern, integrated, and multi-layered air defense system.