AESA VHF radars and PCL/PET systems as a part of Polish air defense modernisation,6,30,7972,lotnictwo,wyposaze
Development of a new generation of radar systems was initiated by the Air Defense Command of the Polish MoD. According to initial concepts one of the main ways of target identification, tracking and acquisition for Wisla (HIMAD) and Narew (SHORAD) batteries should be a long range mobile 3D target acquisition radar temporary named P-18PL during the development process.

Model of the antenna array of P-18PL. The construction is similar to Russian 1L119 Nebo-SWU and RLM-M from Nebo-M complex.

Development of the radar station began in Bumar Electronics(currently PIT-Radwar) according to a R&D program number O ROB 042 001 "Development of a P-18PL AESA radar prototype operating in VHF band for air defense systems" and in cooperation with the Military University of Technology. The program started in 2011 and in 2012 the consortium signed an agreement with the National Center of Research and Development about developing a prototype of the radar until December 2016.

According to plan the "P-18PL" will be a completely new station and not a modernization of the P-18 "Laura" radar. The only similarity will be the operating band - VHF. Due to the fact that the wave length in this band is similar to the size of fighter aircraft VHF radars can detect objects with small RCS (UAVs and stealth aircraft) from large distances. Another advantage of the VHF band is that it's less affected by the atmosphere (including clouds and rain), it's less vulnerable to radiation missiles and active jamming.

The new radar will be a 3D long range station. Because it's supposed to support medium range air defense systems it should be able to detect aerodynamic objects as well as ballistic missiles at the same time. It will be connected with missile batteries via a data link and should provide information about air targets as well as sources of active jamming. Additionally it will also be able to work as a passive radar detecting air targets by analyzing received reflected electromagnetic waves emitted from other sources.

P-18PL will have an antenna will autonomous air-cooled transmitter-receiver modules and radiating elements. AESA antenna will let it electronically form beams in both the azimuth and elevation, change the power output of radiating elements, provide large flexibility in terms of changing frequency and signals coding. Each module will be connected with a digital-analog receiving channel which will make reprogramming the radar and digitally forming of transmitting and receiving beams possible. Entire transmitter-receiver system will be based on an idea of a Software Defined Radar which will allow it for example to emulate the old P-18 radar, making it harder for the enemy to define which radar is scanning the airspace.

The signal processing system should allow digital forming of receiving beams in both plains, adjusting them to a desired work mode, detecting and tracking of airplanes, cruise missiles, ballistic missiles on their entire flight path, helicopters (including the hovering ones), UAVs and their proper classification. The radar will have an IDZ-50 Kwisa long range IFF system.


Another system designed to detect objects for air defense batteries is a hybrid military Passive Coherent Location/Passive Emitter Tracking system (PCL/CET). The project was initiated again by the Air Defense Command of the MoD. It's developed by PIT-Radwar in cooperation with AM Technologies Poland and the Warsaw University of Technology since 2011 and a prototype should be built until December 2016.
PCL/PET system should be based on two concepts - PET PRP-25 Gunica system (left) and passive radar PaRaDe (right)

The system will be built thanks to experience with two systems. PRP-25 Gunica PET system built by Radwar and AM Technologies as well as a Passive Radar Demonstrator (PaRaDe) built by Warsaw University of Technology. Gunica stations are in service within the Polish Air Force since 2010 meanwhile PaRaDe was developed between 2009 and 2011 and tested by the army during military exercises.

Main purpose of the PCL/PET system will be finding, localizing and tracking targets by combining two detection methods - Passive Coherent Location (detecting a target using electromagnetic emission from occasional emitters) and PET - Passive Emitter Tracking (detecting signals emitted by on board plane electronics).

PCL/PET concept by PIT-Radwar

The station will consists of three systems:

PET-ELINT - designed to localize and analyse (in 0,5-18 GHz band) emission generated by on board electronic devices such as radars, radio altimeters, IFF systems, navigation devices or active jamming systems.
PET-COMINT - designed to localize and analyse signals from communication devices
PCL - detecting and analyzing interference in emission of occasional emitters such as FM radios, DVB-T TV or mobile phones.

The PET system will localize the target via Time Difference of Arrival (TDoA) used for example in Czech VERA, Russian Kolchuga or Polish PRP-25 Gunica.
PCL system will use interference in emission of occasional emitters. It will register a signal from an emitter (e.g. a TV tower) and the same signal reflected from an air target (e.g. an airplane) and then compare them to localize the source of the interference.