Module 4. Methods, systems and devices for revealing and measurement of aircraft co- ordinates. Struggle against hindrances. Mono- pulse radar-location. Topic 4.5. Secondary radar-location. Principles and construction methods of secondary radars. Mono-pulse secondary radars. Lecture SSR

Condor series Monopulse Secondary Surveillance Radar (MSSR) systems (United Kingdom), Identification friend-or-foe (IFF) and secondary surveillance radar (SSR) systems Type Family of ground-based MSSR systems.

Description Raytheon System's Condor MSSR interrogators are solid-state, digital, surveillance systems designed to meet International Civil Aviation Organization (ICAO) Annex 10 standards and are billed as providing 'high- probability' of detection ('even in severe multipath and reflection environments') with 'high' reliability. The equipments incorporate very large scale integration chips and microprocessors and deliver 'full' transmission, reception, processing and control capabilities within a single cabinet, with the whole constituting a single interrogator channel.

Typically, systems are supplied in a dual-channel configuration to maximize system availability. Continuous azimuth data is distributed between both channels to facilitate 'fast and seamless' changeover and automatic reconfiguration provides continuity of service without manual intervention. All generated data needed to maintain the target database is passed from the operating to the standby channel so that target reports can be generated 'immediately', thereby minimizing loss of data in the event of channel change.

Adaptive reflection processing provides 'superior' false target suppression without the undesirable side effects associated with azimuth power programming and Improved Interrogator Side Lobe Suppression (IISLS). Built-in test equipment provides continuous monitoring of operational performance and 'extensive' fault detection, with performance statistics and fault diagnosis data being reported both locally (to a local maintenance terminal) and to a remote system control terminal. The known details of two specific Condor MSSR configurations are as follows:

Key contents include - Radar Systems - Fire-control - Surveillance - Navigation - Missile control air defense - IFF and secondary surveillance -Land-based, airborne and naval Military air traffic control - Electronic Warfare Systems - ELINT - COMINT - ECM - Defensive Aids Suites (DAS)

Different sections provide in-depth detail covering - Airborne Active And Passive Countermeasures Systems And Defensive Aids Suites (Das) - Airborne Fire-Control Radars - Airborne Signals Intelligence (Sigint), Electronic Support And Threat Warning Systems - Airborne Surveillance, Maritime Patrol And Navigation Radars - Analysis - Battlefield, Missile Control And Ground Surveillance Radar Systems

- Contractors - Electronic Warfare Systems - Glossary - Identification Friend-Or-Foe (Iff) And Secondary Surveillance Radar (Ssr) Systems - Land-Based Active And Passive Countermeasures Systems And Defensive Aids Suites (Das) - Land-Based Air Defence Radars - Land-Based Signals Intelligence (Sigint), Electronic Support And Threat Warning Systems - Military Air Traffic Control (Atc), Instrumentation And Ranging Radars - Naval Active And Passive Countermeasures Systems And Defensive Aids Suites (Das)

- Naval Fire-Control Radars - Naval Signals Intelligence (Sigint), Electronic Support And Threat-Warning Systems - Naval/Coastal Surveillance And Navigation Radars - Radar And Electronic Warfare Simulation And Training Systems - World Submarine Radar/Electronic Warfare Fits - World Surface Ship Electronic Warfare Fits - World Surface Ship Radar Fits

Condor 2

SPECIFICATIONS OF THE CONDOR MKII Antenna Gain: 27 dBi Horizontal beamwidth 3 dB: / degrees Horizontal sidelobes: -26 dB below peak Roll-off rate (underside): 1.9 dB/degree at -6 degrees point High angle cut-off: -4 dBi at +65 degrees Wind survival 40 mm radical ice: 200 km/hr Temperature: -30 degrees Celsius to +70 degrees Celsius Transmitter Frequency: 1,030 +/ MHz Output power: 32 dBW Duty cycle: Up to 2%, optional 6% Operating modes: 1, 2, 3/A, B, C, D(S and 4 as options) Suppression: Interrogator Side Lobe Suppression (ISLS) (Improved ISLS (IISLS) option)

Log Receivers Frequency: 1,090 +/- 0.2 MHz Sensitivity: -90 dBm tangential Bandwidth (3 dB): 9 MHz Dynamic range: -16 to -86 dBm Suppression: Receiver Side Lobe Suppression (RSLS) Extractors/Plot Processor Multibus II: processors VLSI technology: Monopulse Azimuth Range Code Assembler Target load: Average 600/scan (120/s) (900/scan option) Peak 350/s Standby readiness: Software coupled (hardware option)

Extractors/Plot Processor Video clock I/P: 16 MHz Decode: Up to 4 overlapping replies Antenna check: Built-in antenna HPD plotter Built-in monopulse consistency check: Continuous Reflection suppression: Fixed and dynamic files Output formats available: Radar Data Interface Format (RDIF), Asterix

Monopulse Secondary Surveillance Radar (MSSR) MSSR is a key component of air traffic surveillance infrastructure providing, as a minimum, the position, track, altitude and identity of co-operating aircraft. With a long tradition of technological development stretching back to the very earliest SSR applications, Raytheon MSSR systems continue to offer the highest probability of detection (Pd), even in severe multipath and reflection environments, together with low false target rate and high operational availability.

Comprising field-proven components configured in a redundant and fault- tolerant architecture, Raytheon MSSR systems offer sufficient target capacity to accommodate predicted volumes of traffic growth. Additionally, the extensive application of ‘gate array’ technology makes Raytheon MSSR systems easy to configure and maintain.

Condor Series 300 The Condor Series 300 MSSR is a cost-effective system, modular by design and consequently configurable (and reconfigurable in the field) to meet any, or all, MSSR, Mode S and IFF Mode 4 requirements. In addition to conventional SSR, Series 300 systems output Mode S data to support Elementary and Enhanced Surveillance applications. Mode S decoding and processing is conducted in parallel with conventional SSR processing to ensure proven processes are not compromised and that each function can be optimised individually. Compatible with ICAO Level 2 transponders with Mode S Surveillance Identifier (SI) capability, Series 300 Mode S systems offer mixed, and fully configurable, mode interlace patterns providing concurrent detection of Mode S, MSSR and, where appropriate, IFF Mode 4. To ensure IFF Mode 4 interrogations do not interrupt those in other modes, Series 300 interrogators use Super mode to interlace Mode 4 with Modes 1, 2, 3/A and C in a single interrogation period.

Condor European Mode S ( EMS ) Developed specifically to meet EUROCONTROL requirements for full Mode S functionality in crowded European airspace, the Condor EMS MSSR interrogator is a high specification (ICAO Level 5), high performance Mode S system with full Extended Length Message (ELM) uplink and downlink capacity and a proven ground station network (interrogator clustering) capability. Target tracking responsibility within an interrogator cluster is determined by a coverage maps in the Surveillance Control Function (SCF). Raytheon’s SCF solution is integrated into the Condor EMS interrogator, which enhances reliability, eliminates need for external communications processors and satisfies high integrity requirements for data distribution. Condor EMS systems are operational in clustered networks in Germany and The Netherlands, and operating as independent systems in Hungary, Switzerland and the UK.

Condor MSSR Antennas Raytheon MSSR antennas are designed for performance, endurance and reliability. The Condor Large Vertical Aperture (LVA) Antenna is suitable for co-mounted or standalone MSSR/IFF applications. Designed to operate in all climatic conditions without a radome, its rigid construction enables it to withstand loads and forces imposed by high winds – up to 161 km/hr operational and 200 km/hr survival – and significant ice coatings. Each of 35 vertical radiating columns has 12 dipoles that are phase and amplitude controlled to maximise target illumination and minimise ground illumination. Isolated splitters within the distribution network ensure that radiating columns are less vulnerable to change in performance because of heavy rain or icing, rendering the antenna fail-soft. Designed for applications where a larger antenna is unsuitable, the Raytheon Flat Plate Antenna is lightweight, compact and yet rugged in construction. Weighing only 50 kg and with a length of only 4.3 m, the Flat Plate Antenna provides monopulse operation for MSSR, Mode S and IFF Mode 4 applications, both co-mounted and standalone.

SIR - SECONDARY SURVEILLANCE RADAR FAMILY

FAMILY TREE Monopulse SSR: SIR-M Mode-S SSR: S The SELEX Sistemi Integrati Secondary Surveillance Radar family is a true modular system fully compliant with ICAO recommendations. SIR is normally a dual-channel system with automatic changeover. Single channel configurations are also available. Each SSR channel consists of a transmitter, a receiver and a programmable extractor/controller.

The very power ful processing platform is based on programmed assemblies, which also provide all control signals. Fur thermore, it provides all programmable functions of the transmitter and receiver units. The antenna used normally in conjunction with SIR SSR is the ALE-9 open array antenna, specially developed for monopulse use. It provides high directional proper ties and ver tical aper ture, as recommended by ICAO also for the Enhanced Mode-S.

SIR is available in the basic monopulse version, the SIR-M, and in the full Mode-S version, the SIR-S. The system is designed so that the total cost of expansion is born only by the added units. SIR-M The basic monopulse configuration is based on a programmable transmitter and a 3 channel receiver which uses logarithmic IF-amplifiers.

MONOPULSE ADVANTAGES The main purpose of the monopulse technique is to obtain precise azimuthal information from a single transponder reply. The technique uses sum and dif ference beam patterns, inclusive of phase information, to obtain the correct bearing (of f- boresight angle) of the target with respect to the actual positionof the sum beam. A very precise plot position is thus obtained. Fur thermore, the pulse repetition frequency of the SSR may be reduced, thus minimizing RF pollution.

Another advantage of the monopulse technique is the inherent capability to distinguish aircraft in a garbled echo and to reduce the effect of auto-garbling when multiple receiver paths occur. SIR-S The SIR-M configuration may be upgraded to full Mode-S configuration, the SIR-S. This is obtained by adding modules to the transmitter and by activating proper software items relevant to Mode-S typical functions. To reach full capabilities, a dedicated enhanced Mode-S station is now also available, for use in conjunction with the SIR-S.

ADVANTAGES OF MODE-S The Mode-S eliminates or reduces to a great extent all the inconveniences until now associated with Secondary Radars such as garbling, fruit and over interrogation. The Mode-S interrogation increases the performance of secondary radars in terms of enhanced Surveillance Function by introducing the following capabilities:

All-Call acquisition Lockout Selective addressing with unique aircraft identification code Error detection and correction Adaptive interrogation Single surveillance interrogation and reply per antenna scan

Furthermore, the Mode-S supports station digital data exchange between ground and airborne computers, implementing one of the ATN (Aeronautical Telecomunication Network) air/ground sub-networks. SIR-S equipment main features Use of state-of-the-ar t technology: Latest generation of RF Power Transistors Very Large Scale Integration (SMD technique) Latest generation processors and architectures

Full redundancy of critical items: Two Transmitter Units Two Receiver Units Two Processor Units Cross-coupled configuration: Hot/Stand by Transmitter and Receiver with Processor Units Fault-tolerance: Processor Unit in Master-Slave configuration

EXTENDED PERFORMANCE MONITORING based on: Processing of Replies from the Test Transponder Generation of Replies at RF level with TTG circuitry On-line receiver logarithmic characteristic calibration Extensive on-line BITE for LRU fault detection

Improved azimuth monopulse estimation Two algorithms are used for the azimuth angle estimation: Amplitude and sign processing (ASP) Dot Product Processing (DPP) A selection logic activates the DPP algorithm for replies very close to the boresight in order to minimize the estimate error.

Mode-4 compatibility Suitable hardware inter face for external cryptographicdevice is available. Dedicated extraction logic allow the extraction of friend- foe-unknown information Full Mode-S operation SIR-S equipment fully complies with ICAO latest Mode-S requirements and with the Eurocontrol EMS (EuropeanMode-S Station) requirements.

SIR EQUIPMENT CHARACTERISTICS TRANSMITTER UNIT Technology: Full Solid State and plug-in devices Configuration: Two independent transmitting chains (Sum, Omni) in the SIR-S version Single chain with automatic RF switch in the SIR-M version TX frequency: 1030 MHz ± 0.01 MHz ( SIR- S) Output power: > 62 dBm (32 dBW)

ATC & MIL modes: Fully suppor ted (mode 4 included) TX monitoring logic: BITE and status repor ting Malfunction detection at LRU level Protection Circuits Shor t and open circuit Over-voltage from P.S. faults Excess duty cycle and temperature on heat sink Receiver unit: Technology: Full Solid State and plug-in devices Configuration: Three amplitude and phase matched LOG channels

Signal Output characteristics: SUM, DIFF and OMNI channels: 2 identical video outputs for the two extractors Phase detector channel: 2 identical outputs for the two extractors RX control logic: Autotest procedure for each channel Test Target Generator (RF Signal)

RX monitoring logic: BITE and Status Repor ting Malfunction Detection at LRU level Protection Circuits Over-voltage from P.S. faults Input inter ference protection Dynamic range: 90 dB Noise figure: <3.6 dB

PROCESSING UNIT It is a multiprocessor system based on a Power PC hardware platform, which can be easily upgraded as capacity demands growth. Due to its modular design, technological enhancements can be incorporated in the HW platform without impact on the architecture and the SW applications. The receiver inter face consists of dedicated boards per forming all the necessary operations to process the received replies using 4 A/D conver ters (Sum, Diff, Omni and Sin) with 10 bit word and 20 MHz sampling rate. All the boards inter face to each other by a VME Bus.

PROCESSOR MAIN FUNCTIONS Uplink control: Sectorial control of Tx power Pulse to pulse modulation PRF selection Interlace management Interrogation staggering Interrogation modes management Frame management (SIR-S version)

Downlink Control: Sensitivity time control (STC) and range azimuth gated STC Adaptive thresholds for multipath rejection Pulse & Reply Processing: Rx Output Processing Pulse Detection Reply Processing for modes 1,2,3/A, B, C, D, 4 Reply Processing for Mode-S (SIR-S version)

Plot Extraction: Correlation among replies (ATC, MIL and Mode-S) received during the "dwell time" and construction of plots (for A/C targets) and target repor ts (for Mode-S targets) Channel Management: It includes all the functionalities necessary to use the RF channel, in order to accomplish the surveillance and communication functions of the radar. Timing of the channel activities is per formed in order to accomplish correct interrogation and accurate management of the relevant replies.

Ancillary Functions: BIT (Built-In-Test) System Communication (serial line/LAN ETHERNET TCP-IP/X.25) Intercomputer (Master-Slave management/processing synchronization/Data Base alignment)

MODE-S OPERATIONAL STATION SIR-S operational capabilities are fully exploited by inser ting the equipment in the SELEX Sistemi Integrati Mode-S Operational Station, developed following a wide research, experimental activities and field experience through operational use.

The station has been designed to all performance and functional characteristics specified by Eurocontrol for use in the European Airspace. The items in the station carry out the following tasks in addition to the above mentioned SIR-S function:

Radar data filtering and tracking: Radar data are processed in order to estimate the current and predict the future speed and position of the aircraft, reducing measurement errors. Predicted positions in scan i are used for selective interrogations in scan i + 1.

Surveillance Coordination: Mode-S interrogations per formed by associated stations are coordinated and handover is managed according to sensor coverage maps. Data Link: Enhanced surveillance services are provided to local and remote users through the Mode-S communication link managed by the station. Supervision: Evaluation of different operative functions control equipment status and diagnostic facilities.

ASR-E

Monopulse Secondary Surveillance Radar The modular MSSR 2000 I system (here a civil variant)

The standard MSSR interrogator for the ASR-E system is the MSSR 2000 I. The Interrogator MSSR 2000 I is of modular design. The system fulfills all requirements for a European Mode S Station for elementary surveillance as well as for enhanced surveillance, ground/air data link including de-centralized control in a cluster application. The Interrogator MSSR 2000 I includes reasonable growth capability to allow the incorporation of new modes or features in the future as a result of its modern technology.ASR-EInterrogator

MSSR 2000 I interrogator including a combiner unit with a crypto computer

The MSSR 2000 I operates in the following modes which conform to ICAO Annex 10 and STANAG 4193 part requirements: - Mode 1,2,3/A,C,4 - Mode S (level 4) - Mode A/C/S All-Call - Mode A/C only All-Call - Mode 1,2,3/A,C mode interlace - Supermode

The MSSR 2000 I can interrogate in „interlace modus”, (sequences of different modes freely programmable by the user through menu guided input)e.g. M1:M1 or A:A:C or any other desired sequence. The design of the MSSR 2000 I includes the capability to be upgraded to the new military Mode 5.interlace modus

Specifications frequency: 1030 / 1090 megahertzes pulse repetition time (PRT): pulse repetition frequency (PRF): pulsewidth (PW): receive time: dead time: peak power: up to 2 kilowatts average power: displayed range: range resolution: beamwidth: hits per scan: antenna rotation:

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