MSAD Black Shaheen

Elements of the Black Shaheen.

The Shaheen al-Aswad (Arabic: شاهين الأسود, English: Black Shaheen) is an integrated defensive electronic warfare suite, developed by the Central Institute for Radio-Electronics (MRER), for the namesake TaH-27MJ Shaheen Alaswad fighter and to equip late-model TaH-27 Shaheen fighters. Based on experience gained with the development of radio-electronic systems for light tactical fighters such as the TaH-25 Snuonuo and early-model TaH-27s, the Black Shaheen was intended to be a lightweight integrated electronic warfare system, with the explicit purpose of countering the rise of modern pulse-Doppler and low probability of intercept airborne emitters. In addition to the TaH-27MJ, the Black Shaheen system is also included on export TaH-29 Daqanoushs instead of the Khanjar, and can be fitted to other light fighters.

Compared to the MSAD Khanjar system for Riysian TaH-29s, which is itself based off of experience with the Black Shaheen, the Black Shaheen is significantly lighter, cheaper, and more compact, in order to fit into the confines of the TaH-27 tactical fighter airframe. The Black Shaheen is optimized against fighter radars and surface-to-air/air-to-air missile seekers, with some capability against short range surface to air missile system radars. Total weight is under kilograms, and it provides 360-degree detection and protection for the aircraft.

Components

The Black Shaheen is a digital, software-based system, based on a federated system architecture with a central computer overseeing the processors for each subsystem. The federated architecture allows for rapid processing and dissemination of information, for quick and effective automatic and manual operation, while the software base allows for continuous upgrades without hardware replacement. The entire system is modular, allowing for quick repair.

Operation of the Black Shaheen is either automatic or semi-automatic. In automatic mode, emissions data from the ESM array is processed and the highest threat classified, possibly supplemented by information from a threat library, which is then followed up by activation of whichever countermeasure mode(s) is deemed effective against the threat. Semi-automatic operation means that, while elements of the system will operate autonomously such as jamming look-through and emitter classification, selection and activation of countermeasures is left to the pilot.

Central Processing System

The Central Processing System (CPS) oversees all the subsystem computers, processes and fuses emissions and tracking data from and for the pilot and electronic warfare subsystems, and commands the subsystems to react to threat emissions depending on the pilot's preference. The system comprises 20 TANTA microprocessors processing in parallel, with software-defined function, for quick adaptability and re-programability. In addition to oversight, the CPS also is linked to a built in self-testing system monitoring the status of the entire Black Shaheen system, including the CPS itself. This allows for quick testing of each component to ensure its functionality, and to alert ground crews before takeoff of any failures in the system.

The CPS can operate the system in a fully automatic mode, or with varying levels of pilot/operator intervention, for either worry-free countermeasures operation or fine-tuning a response according to mission needs. Additional features include the possibility of being loaded by the operator with a threat library of several hundred different entries, along with specific directives for effectively countering each threat. CPS management also allows for advanced countermeasures modes, notably "look-through-while-jamming" for countering electronic threats; this mode forcibly pauses or modulates jamming power during a jamming mission, to allow the ESM component to analyze enemy emissions activity. The software defined CPS allows for fine-tuning of its operations, even in field conditions.

AEKR-176 ESM/Radar Warning Receiver

The AEKR-176 system is a digital, programmable EEPROM electronic support measures system, primarily designed to operate in a high-density threat environment populated by modern pulse-Doppler and low probability of intercept (LPI) emitters. It is a two-part system, consisting of a wideband instantaneous frequency measurement (IFM) receiver for volume detection and classification, and a wideband superheterodyne (SHD) receiver for improved detection against low-power and LPI threats. A wideband SHD receiver is used in place of a more sensitive narrowband SHD receiver, due to the former having better bandwith, a quicker reaction time, and a higher probability of intercept. The system consists of 10 antennas placed around the airframe, giving it a coverage of 360 degrees in azimuth. The AEKR-176 has a high mean time between failure of 725 hours, and can be repaired in less than one hour. Total weight is just under 55 kilograms, allowing retrofitting into small combat aircraft.

Frequency coverage of the system ranges from 1 to 18 GHz, covering virtually all important emitting threats, such as AWACS at 3 GHz, Patriot MPQ-65 radar at 6 GHz, and the commonly-used X-band from 8-12 GHz. It has a programmable threat emitter library, which can store up to 1,500 unique emissions patterns, corresponding to 120-150 different systems, and can be reprogrammed in 90 seconds or less. When operating, the AEKR-176 will by default display the 15 most dangerous threats detected, with more able to be cycled manually, as well as any important information gathered. The system can effectively receive pulse-Doppler, CW, interrupted CW, pulse compression, frequency agile, jitter/staggered pulse modulated, and LPI emissions. Fingerprinting of the emitter is automatic, drawing on the threat library to identify the specific emitter and its platform. If it can not be determined, the AEKR-176 will use the wave's characteristics to classify it as one of several generic classifications, such as "search" or "navigation" radar, with relevant characteristics displayed to the pilot.

Direction finding is done with amplitude comparison, with a 5 degree accuracy with IFM and an improved 3 degree accuracy for the frequency tuned in to by the superheterodyne receiver, with a precision of 1 degree. The frequency of the emitter can be detected with an accuracy of 5 MHz for IFM and 1 MHz for SHD, with a precision of 1 MHz. In addition to direction finding, the AEKR-176 can conduct azimuth/elevation-based emitter geolocation in compatible airframes, combining INS and GNSS data with DF data to give the geographical position of the emitter with a CEP of around 50 meters. The detection range against an active emitter depends on its power and gain, but it will never be less than 1.2 times the emitter's detection range against a typical fighter-sized target of 3 square meters, even against LPI waveforms. Information from the AEKR-176 can be used to target anti-radiation missiles without the need of an external pod.

Operation of the ESM system is automatic and relatively simple conceptually. The IFM receiver is the primary receiver, divided into four octave units (1-2 GHz, 2-4 GHz, 4-8 GHz, 8-16 GHz) comprising the range of the system, simultaneously measuring across this range and instantaneously detecting and measuring emitting frequencies. The IFM receiver handles high-density volume search and identification/direction finding of targets, with switchable filters allowing for the processing of high duty cycle signals. The SHD receiver conducts its own independent search of the operating range, having better sensitivity and direction-finding accuracy than the IFM receiver, but is relatively slow to respond and has limited bandwith. While independently searching, it can detect an emitter at a much farther range than the IFM receiver, and is better at processing signals simultaneously emitting in the same frequency, but its slow retuning limits its effectiveness at volume search. To link the two, upon detection of certain signals, the IFM array will slave the SHD receiver and direct it to a certain band to make use of its improved sensitivity, and vice versa. Combined, a near 100% probability of intercept can be guaranteed.

Arguably, the most important feature of the AEKR-176 is the ability to automatically and reliably intercept and locate emitters operating in low probability of intercept modes. The use of digital processing downstream of the receivers mostly counters the high processing gain of LPI emitters, allowing even the IFM receiver to detect LPI waveforms at standoff distance, as well as other means. The actual details of how the AEKR-176 reliably detects LPI waveforms are classified, but appears to be based on parallel processing of multiple detection and processing algorithms - likely Wigner-Vile, quadrature, or cyclostationary, where the processed image from all three algorithms are combined to provide a single profile of the emitter for identification. The SHD receiver's increased sensitivity increases the range of detection.

AETR-203 Active Jammer

The AETR-203 is a lightweight, digital, software-defined noise and deception jammer, designed primarily to counter air-to-air and surface-to-air missile seekers and fighter radars, with some capability against certain SAM radars. Emitting from six antennas, located in the wings, nose, and tail, the AETR-203 provides jamming coverage of 360 degrees azimuth and +/- 90 degrees elevation to an aircraft. It consists of two generator blocks - one for a different frequency band - with nine line replaceable units, and has a high mean time before failure of 140 operating hours with a mean time to repair of less than 30 minutes. Total weight of the jamming system is only 73 kilograms.

The operating range of the AETR-203 is from 6 GHz to 12 GHz, covering the H, I, and J bands, which covers fighter radars and most radar-guided missiles, as well as some SAM system radars. Quadrature DRFM techniques are used in the AERT-203, to give it the processing gain and low sidelobe emissions needed to jam modern pulse-Doppler radar sets. Digital operation combined with certain deception jamming techniques allow it to effectively implement stealth modes, where the target does not realize that it is being interfered with. Two operating modes are used, one for jamming traditional pulse-Doppler radars, and one for jamming continuous wave sets.

Jamming modes of the AETR-203 include:

• Cross-eye/phase front (default active, applied to all jamming modes when activated).
• Spot noise jamming.
• Barrage noise jamming.
• Bin masking (range and velocity).
• Low-delay range gate walk-off.
• Velocity gate pull-off.
• False Doppler signal generation (frequency oscillation, fraction PRF).
• Cross-polarization.
• Formation jamming (only among datalink-equipped platforms).
• Blinking.
• Terrain bounce.

Certain modes can be used simultaneously. When operating in semi-automatic mode, the jamming system will give recommendations to the pilot on which modes to use. Power management is used to reduce the chance of being detected as well as spare power for use by other systems. Up to 5 targets can be jammed at once.