Military aspects on the use of Mode S

Military aspects on the use of Mode S and Mode S related Systems

Structure • Military Operational Requirements on Identification • Conflict areas identified due to the civil use of Mode S • Improvements of military systems using Mode S • Military Mode S Architecture • Military applications for Mode S based Systems

NATO Military Operational Requirement (MOR) on Identification Aircraft IFF Fighter Bomber Fighter Aircraft Air/Ship to Ground ID System Close Air Support Mode S Anti-Tank Helicopter FO/FAC Warship Ground Vehicle SAM Long Range Surveillance

Civil Mode S Traffic Scenarios Mode S Conspicuity Code 3700 FL 100 3700 Mode 3/A 2711 3711 4711 GND ASR complete Mode S flightpath Conspicuity Code 3/A Group Code ASR Mode 3 A/ Mode S flightpath 3/A Group Code Conspicuity Code ASR Mode 3 A flightpath

IFF 3/A- versus Mode S Interrogation Capability 3700 LH 123 4711 3700 BA 5643 3700 GAF 2213 3 A Code, common IFF Flight Plan Callsign (ID) With Mode S

Propability of acquisition for different Lock-out procedures 200 180 160 140 without lock- 120 out 100 with lockout 80 60 40 20 0 2 3 4 5 6 7 8 9 10 No. of needed interrogations for acquisition propability > 99% with and without lock-out

Propability of acquisition for different Lock-out procedures No. of acquired Transponders in % depending on the number of antenna-turns

Summary on acquisition Strategy The use of lock-out procedures based on different Interrogator Codes is at least for all fixed military Mode S Sensors absolutely necessary !!! For the acquisition of a/c flying in close formation a stochastic acquisition procedure depending on the number of a/c improves the performance of the mode S sensor very much !!!

Beneficial use of Mode S on airborne Interrogator platforms The Radar Antenna is large against the used wavelength therefore its beam is relatively sharp. The IFF Frequency is much lower, so the Beam of the IFF Antenna is quite broad. One of the 4 targets with identical range has to be Identified, but which is it? With Mode S the position of all responding Targets could be extracted and the target identified

German military ATC and Long Range Air Defense Radars Figures EUROCONTROL 10/99

EUROCONTROL ICAT Tool, II Code 5 (DFS Cluster South) EUROCONTROL Interrogator Code allocation Tool 23. 09. 99

Civil and military Cluster sizes 6 civ. Radarstations with Cluster Code 3 II 3 II 3 2 mil. Long Range Radarstations with overlapping Coverage

Folie 3 Parallel use of identical II Codes in overlapping clusters II Code: 3 Military Control and Reporting Center Air Defense Track Server mil. RADNET Firewall civ. RADNET Track to Track Correlation Asterix Cat 348 Asterix Cat 48 Regional Civil Control Center Enroute Traffic Track Server

Creation of military ASTERIX Formats Mil. ASTERIX Cat 348 Target Data mil. Target Data EUROCONTRO L ASTERIX format Position CAT 48 Mode S (already defined) Status Data etc. Military Format Extension Strobedata Jamminginformation

Folie 3 Civil / military Mode S Radar Data Exchange local militar y user mil Track military ASR mil Plot military user Control civ Plot Gatewa y Firewall Military Track Server military Long Range Radar Civil RADNET civil En-Route Radar military RADNET civ Track civil ASR local civil user civil Track Server Control civil user

Military use of Mode S tion a rog r Inte ll S de o nly o l ca al M M e. S od ply re it a 4 B 2 th wi ess dr

Military use of Mode S tion ga o tive ec ode M r ter In sel S Mo e. S d ply re ith w F ign alls PC

Military application: Deviation Advisory via Mode S Functions of g tin sis on e: n c ag tio ess a og y m err or int vis ive ad 3°, t n 12 e lec tio Se via ing zon e ad er D he ng to da rse ring ou te c er e en alt ar „ u yo

ACAS II Functionality, Mode S based Traffic Advisory Area Resolution Advisory Command Area IFF Mode 3/A, C Transponder SSR Mode 3/A, C Transponder 1. Mode Aonly, Mode C only interrogation 2. Mode A Mode C Reply Range, Bearing 1. Mode C only “All Call” Interrogation E-TCAS 2. Mode C Reply Range, Bearing, Altitude 1. Mode S Transponder squitters with 24 Bit Adress ACAS 2. Mode S Interrogation with received 24 Bit. Adress Range, Bearing, calculates closure rates 3. Mode S Reply with 24 Bit Adress

ACAS Traffic Advisory in a civil environment Traffic

ACAS Resolution Advisory in a civil environment Without Intercept Bit Descend Now !

ACAS IC Bit escort announcement in a civil/military environment With Intercept Bit set Military Escort Mission

Automated Dependent Surveillance Broadcast System (ADS-B) Global Navigation Sattelite Communication Sattelite Intercepted Signals Give away: -Performance -Availability -TTP Nav. Sys generates Position Reports GNSS based via Mode S Broadcast ATC System ADS-B Receiving Station

German Order of Electronic Identification • Equipped with hand held receiver and Notebook anyone is able to receive and exploit a/c performance and availability data ! • These data are classified ! • If mil. uses fixed 24 bit adresses, anyone could rapidly exploit these data for all military aircraft ! • To avoid Exploitation the 24 Bit adresses must be masked (e. g. changed for each mission)

Mode S Extended Squitter Position Reporting (ADS-B) LH 123 No ID without Mode S BA 5643 GAF 2213 Without active Interrogation: - Flight Plan Callsign - Longitude - Latitude - Height

Interoperability of Mk XII A/S in Mixed Environments ADS-B Mode S Position Reporting Mil IFF Position Reporting Tracker - IDCP FO/FAC Mode S MSSR Mil IFF Air/Sea Mil IFF Ground ADS B, Mode S IFF Report Mil Tactical Data Link

Intended use of military ACAS Communication ACAS Position keeping

Military Hybrid Surveillance with ADS-B ACAS Communication Mode S Position reporting in Formations (Hybrid Surveillance) Position reporting with Mode S provides Situational Awareness (requires Mode S downlink receive mode)

Traffic Information System – Broadcast (TIS-B) The combined Air and Ground Picture will be broadcasted to ground traffic on the airport and to airtraffic in the vicinity of the Terminal Area to inform on the traffic situation. TIS-B Traffic Information Volume Service Volume Source: EUROCONTROL 2002

Military use of Traffic Information System – Broadcast (TIS-B) Instead of the combined Air and Ground Picture, the area of a Danger- or Restricted Zone could be broadcasted to all airtraffic in the vicinity TIS-B Traffic Information Volume Danger or restricted zone

Summary Military aspects on Mode S are different from civil ones but military use of Mode S and Mode S related functions will: • Enhance civil/military Interoperability and flight safety • reduce misinterpretation of reactions in conflict areas and • increase Situational Awareness in low level conflict areas Recommendation: Support civil/military working groups at national and international organisations as EUROCONTROL, NATO and ICAO to improve civil / military coordination.

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