1. Using PRI Prediction to Improve ECM Effectiveness By Scott McDonald & Ken McRitchie Ottawa, Ontario, Canada Visit us at http://www.mc-cm.com MC Countermeasures Inc.

2. Sept 042Visit us at http://www.mc-cm.com Overview Introduction Benefits of Prediction PRED Features PRED Performance Timeshare Basics Applications Summary

3. Sept 043Visit us at http://www.mc-cm.com PRI Prediction Prediction vs Tracking Typical radar environments are complex – Many emitters -scanning/non-scanning – Conventional pulse, pulse Doppler, etc. Focus is on DRFM-based ECM – other applications such as VCOs also possible – DRFM generally “single threat” device

4. Sept 044Visit us at http://www.mc-cm.com Single Emitter

5. Sept 045Visit us at http://www.mc-cm.com A Problem – Interleaved PRI Patterns

6. Sept 046Visit us at http://www.mc-cm.com DRFM Enables Uprange FT

7. Sept 047Visit us at http://www.mc-cm.com But Only for Constant PRI!

8. Sept 048Visit us at http://www.mc-cm.com Benefits of PRI Prediction Works in many cases where trackers won’t Generate up-range false targets even with staggered PRI patterns Compensate for jammer throughput delay Fade + Fast re-acquisition on scanning radars Operate in dense environment –Pulse train sorting –DRFM write control

9. Sept 049Visit us at http://www.mc-cm.com RGPI >> PRI, 4 el Stagger

10. Sept 0410Visit us at http://www.mc-cm.com (5sec) Fade + Re-Acq

11. Sept 0411Visit us at http://www.mc-cm.com PRED Series Features Fast “learning” –No a priori data used –Not susceptible to war modes 0.5 µs < PRI < 20 ms > 128 stagger positions Adaptive acquisition Prediction < 250 ns

12. Sept 0412Visit us at http://www.mc-cm.com Features (2) 4 parallel predictor channels Real-time de-interleaving Automatic channel selection, timesharing, ECM selection Integrated coherent ECM –RGPI –CRBM (v.s. head-to-tail) –FT Range >> PRI Embedded user memory

13. Sept 0413Visit us at http://www.mc-cm.com Jamming 1 of 6

14. Sept 0414Visit us at http://www.mc-cm.com Head to Tail

15. Sept 0415Visit us at http://www.mc-cm.com CRBM

16. Sept 0416Visit us at http://www.mc-cm.com Performance

17. Sept 0417Visit us at http://www.mc-cm.com PRED Block Diagram

18. Sept 0418Visit us at http://www.mc-cm.com Operating Modes Acquisition –Adaptive process –One complete pattern frame max. –Multiple threads for more efficient pattern handling Verification –Ensures proper PRED lock –User defined # PRIs: usually >10

19. Sept 0419Visit us at http://www.mc-cm.com Prediction Algorithm

20. Sept 0420Visit us at http://www.mc-cm.com Operating Modes (2) Track –Monitors PRI, breaks if error > tolerance –DRFM Write command “gated” to prevent overwriting memory Fade mode –False target strobes generated for defined period –Fast reacquisition

21. Sept 0421Visit us at http://www.mc-cm.com TGPre-trigger

22. Sept 0422Visit us at http://www.mc-cm.com Integral FT Generator

23. Sept 0423Visit us at http://www.mc-cm.com Adaptive Prediction Does not require a priori radar information Responds very quickly – great for long staggers or small illumination times Improved performance against scanning radars –Predictions can be accurate during acquisition of pattern –fast reacquisition – typically only a few PRI – increased ECM effectiveness. Multiple Adaptive Processes during acquisition –Refine prediction within PRI as needed

24. Sept 0424Visit us at http://www.mc-cm.com Adaptive Prediction

25. Sept 0425Visit us at http://www.mc-cm.com Dwell Shift

26. Sept 0426Visit us at http://www.mc-cm.com Dwell Shift

27. Sept 0427Visit us at http://www.mc-cm.com Challenges Missing pulses: fades, effective jamming, scanning radar modes, receiver blanking Extra pulses: interleaved pulse trains, jammer OOB response (spurs, harmonics) –Time gating and frequency sorting very effective Sine or wobbulated PRI patterns

28. Sept 0428Visit us at http://www.mc-cm.com (25%) Missing Pulses

29. Sept 0429Visit us at http://www.mc-cm.com Missing Pulses

30. Sept 0430Visit us at http://www.mc-cm.com Dense Environment

31. Sept 0431Visit us at http://www.mc-cm.com Sinusoidal PRI patterns

32. Sept 0432Visit us at http://www.mc-cm.com Wobulation/Sine Pattern Tests >10,000 waveforms tested (variations about nominal parameters) On average, PRED locked on in ~100 PRI Overall accuracy during acq: ~40% Overall accuracy during track: ~99%

33. Sept 0433Visit us at http://www.mc-cm.com RF & Time Gating Composite video sorted and RF windows assigned dynamically to each channel Active channel selected based on: –Signal activity –Scanning/non-scanning priority –ECM: channel not selected if NO_ECM specified Up to 8 RF reject bands defined by user, updated real-time

34. Sept 0434Visit us at http://www.mc-cm.com Timesharing (IR&D) application of PRI Prediction Use a single DRFM to jam multiple radars simultaneously Encompasses both: –Real-time pulse de-interleaving –Real-time control of DRFM Read and Write Algorithm calculates optimal allocation

35. Sept 0435Visit us at http://www.mc-cm.com Timeshare Architecture

36. Sept 0436Visit us at http://www.mc-cm.com Timeshare, ECM Selection 1 of 8 ECM techniques assigned based on: –PRI range (low, medium, high) –PW range (narrow or wide) –Scanning or non-scanning Permits selective jamming of specific emitters or radar modes simply with time gating DFD/IFM.

37. Sept 0437Visit us at http://www.mc-cm.com Signal Environment

38. Sept 0438Visit us at http://www.mc-cm.com Signal Environment

39. Sept 0439Visit us at http://www.mc-cm.com Timeshare & ECM Select

40. Sept 0440Visit us at http://www.mc-cm.com Auto ECM Selection

41. Sept 0441Visit us at http://www.mc-cm.com Jam 1 – 6 of the Emitters

42. Sept 0442Visit us at http://www.mc-cm.com Benefit of RF Sorting

43. Sept 0443Visit us at http://www.mc-cm.com Applications - Isolation Many antennas compete for little space in most EW installations –Leads to insufficient isolation to transmit and receive simultaneously –Precludes cover pulse ECM OR –Prevents DRFM contents from being updated Situation corrected with PRI prediction

44. Sept 0444Visit us at http://www.mc-cm.com A Second Problem Situation Weapon Systems that use separate Acquisition and Track radars –(Generally) not good enough to jam just the tracker

45. Sept 0445Visit us at http://www.mc-cm.com Timeshare Track & Acq

46. Sept 0446Visit us at http://www.mc-cm.com RF Agility Many non-Coherent threats RF Agility can be implemented as: –Switching between preset channels –Spin tuned magnetron The process involved in attempting RF prediction is quite similar to PRI prediction

47. Sept 0447Visit us at http://www.mc-cm.com RF Agile Sources

48. Sept 0448Visit us at http://www.mc-cm.com RF Prediction

49. Sept 0449Visit us at http://www.mc-cm.com Adding RF PRED

50. Sept 0450Visit us at http://www.mc-cm.com Typical RF Agility 200 Hz or 5 ms cycle If PRI < 1ms, can get shape of curve RF made "random" by staggering the PRI Need to predict PRI first, then get next RF from curve

51. Sept 0451Visit us at http://www.mc-cm.com Summary (1) PRI prediction greatly improves the effectiveness of a DRFM in modern EA applications –Prediction circuitry is not standard in most systems MC Countermeasures has developed a line of predictors that can be easily interfaced to existing systems –Can be integrated with existing TG –Provide additional TG capability –Work around insufficient antenna isolation

52. Sept 0452Visit us at http://www.mc-cm.com Summary (2) PRI prediction channels can be used to selectively track or ignore specific emitters. PRI prediction reduces the effects of overlapping or missing pulses. Timesharing – jam multiple radars with a single ECM asset –Automatic ECM selection (mini-receiver)

53. Sept 0453Visit us at http://www.mc-cm.com Summary (3) RF Prediction can be added to a PRI predictor in order to extend the capability of the jammer. Chipset to be available in 2005 for OEM requirements.

54. Questions For further information, please feel free to contact us at: MC Countermeasures Inc. http://www.mc-cm.com 39 Robertson Road, Suite 256 Nepean, Ontario, K2H 8R2 Canada Tel: +1 (613) 721-1552 scott@mc-cm.com Fax: +1 (613) 721-1553 ken@mc-cm.com