ATS-SSR introduction and basic principles.ppt
- 2. SECONDARY SURVEILLANCE RADAR INTRODUCTION AND BASIC PRINCIPLES Air Traffic Systems
- 3. Radar Picture Timing & Control Transmitter Pulses TX RX & PROCESSING Received Signal Basic Primary Radar
- 4. DISADVANTAGES OF PRIMARY RADAR High Power Clutter Permanent Echo's Weather i.e. Rain etc. Identification
- 5. Radar Picture Timing & Control TX RX & PROCESSING Basic Secondary Radar SSR Tx 1030 MHz Rx 1090 MHz 123 ABC Decoder Secondary returns
- 6. Military A/C Ident - Mode 1 3µs Military Mission Ident - Mode 2 5 µs Joint Military & Civil A/C Ident - Mode 3/A 8 µs Civil A/C Ident - Mode B 17 µs Altitude Data - Mode C 21 µs Modes and Pulse Spacing
- 7. SSR Questions (Modes) Who are you ? (Mode 1 and 3/A) What is your altitude ? (Mode C) What is your mission number ? (Mode 2) Are you FRIEND or FOE ? (Mode 4)
- 8. Mode Interlacing The ability of the system to automatically change modes. This enables more diverse information to be gathered.
- 9. Military transponder set to :- Mode 1, code = 1100 Mode 3/A, code = 4170 Mode C, code = h1 Civil transponder set to :- Mode 3/A, code = 2210 Mode C, code = h2 Military Civil No 2210 h2 No 2210 h2 No 2210 h2 1100 4170 h1 1100 4170 h1 1100 4170 h1 Coded Replies 1 3/A C 1 3/A C 1 3/A C Mode interlace pattern 1, 3A, C MODE INTERLACING h1 h2
- 10. EMERGENCY REPLIES CIVILIAN EMERGENCY GENERAL EMERGENCY - 7700 RADIO FAILURE - 7600 HI-JACK - 7500
- 11. ADVANTAGES OF SSR OVER PRIMARY RADAR POSITIVE IDENTIFICATION CLUTTER ELIMINATION LOWER POWER FOR EQUIVALENT RANGE ACCURATE HEIGHT INFORMATION EMERGENCY INFORMATION
- 12. DISADVANTAGES OF SSR INTERROGATIONS VIA SIDE LOBES FALSE REPLIES UNCORRELATED IN TIME (FRUIT) GARBLING TRACK WANDER
- 14. 200 Miles 80 miles Aircraft A Aircraft B P1 P2 P3 2 s INTERROGATION SIDE LOBE SUPPRESSION Aircraft C
- 15. Site A PRF 250Hz Site B PRF 260Hz F.R.U.I.T.
- 16. FRUIT Correct reply De-fruited video O/P DEFRUITER PRINCIPLE 1 PRF DELAY Coincidence Gate (Frame pulses + 2 information..) First PRP Replies Second PRP Replies
- 17. GARBLE A4 B2 D2 D4 F2 A2 C2 C4 F1 End of pulse train from aircraft A Beginning of pulse train from aircraft B Overlapping replies OVERLAPPING
- 20. THE MONOPULSE SYSTEM ELIMINATES TRACK WANDER BECAUSE ONLY ONE PULSE FROM A REPLY TRAIN IS NEEDED TO OBTAIN AN ACCURATE BEARING.
- 21. BORE SIGHT COMBINED SUM & DIFFERENCE PATTERNS
- 23. Cardion Secondary Surveillance Radar Antenna mounted on Tactical Watchman Mounted on T101 Air Defence Radar
- 24. AIR TRAFFIC CONTROL CIVILAIRCRAFT MILITARY AIRCRAFT MARITIME AIRCRAFT NAVAL SYSTEMS MISSILE SSR SYSTEM APPLICATIONS
- 26. This is my discrete address MODE S Bit 1 Bit 2 Bit 3 Bit 4 1 0 1 1 1 1 0 0 0 0 Bit N Preamble 8.0 s I am able to reply to your “ALL CALL” because I have Mode S Data block 56 s or 112 s 0.5 s 0.5 s
- 27. The future of SSR Mode S – becoming compulsory under EASA rules CSSR and MSSR don’t support Mode S
- 28. Airfield layout
- 29. Any Questions