The Old Cat and Mouse Game Continues

Transcription

1 The Old Cat and Mouse Game Continues or, How Advances in Radar Development Drive Testing Requirements for Next Generation EW Systems by: Walt Schulte Agilent Technologies Microwave and Communications Division Feb 2012 EWCI

2 What is Important to You? If you fly one of these... Or the latest hot rod 2 10/16/2012

3 EW Threat Identification Yesterday Early RWRs were only able to identify a limited number of threats Threat environment was fairly stable: Radar transmitter characteristics were rigidly constrained by single high-power master oscillator power amplifier devices, like magnetrons Radar systems had limited pulse parameter flexibility due to analog pulse generation circuitry Radar antenna characteristics were constrained by single large aperture antennas Radars were generally single-mode and single function systems making them easy to identify because their signature was the same yesterday, today, and tomorrow. 4 10/16/2012

4 EW Threat Identification Yesterday An F4 pilot s worst nightmare Early radar transmitter s magnetron SA-2 track while scan fire control radar could track six targets simultaneously Most magnetrons were single frequency devices with limited power control capabilities 5 10/16/2012

5 EW Threat Identification Today Modern RWRs must keep up with today s threats and must be highly adaptable Today s threat environment is constantly evolving with modern digital processing and as international relations can change on a moments notice: Modern radar systems use frequency agile TR modules that can be programmed to adapt to a dynamically changing electromagnetic environment and specific mission requirements Modern radar systems pulse characteristics are dynamically programmed to extract the most information from the target Modern radar systems generally utilize phased array antenna systems which allow for dynamic changes in antenna characteristics and allow tracking of multiple targets at the same time. Most modern radar systems are multi-mode multi-functions systems whose RF signature is constantly changing, complicating identification. 6 10/16/2012

6 EW Threat Identification Today Modern RWRs must keep up with today s threats and must be highly adaptable Today s threat environment is constantly evolving with modern digital processing and as international relations can change on a moments notice: Modern radar systems use frequency agile TR modules that can be programmed to adapt to a dynamically changing electromagnetic environment and specific mission requirements Modern radar systems pulse characteristics are dynamically programmed to extract the most information from the target Modern radar systems generally utilize phased array antenna systems which allow for dynamic changes in antenna characteristics and allow tracking of multiple targets at the same time. Most modern radar systems are multi-mode multi-functions systems whose RF signature is constantly changing, complicating identification. 7 10/16/2012

7 EW Threat Identification Today Electronically Scanned Phased Array Radar Typical radar TR module Can track multiple targets simultaneously with multiple antenna beams Several thousand TR modules would be used in a typical AESA radar Module controls amplitude and phase for each antenna array element Frequency diversity can be simply programmed at the manifold feed. 8 10/16/2012

8 Maintaining RWR Performance Considering the dynamic nature of today s radar systems and dynamics of the modern electronic battlefield, radar threat tables must be constantly updated As threat tables are updated and verified, RWR reprogramming must be pushed out to operational aircraft. How do program managers ensure that RWRs can correctly respond to newly programmed threats? RWRs must be tested with signals that simulate realistic radar signatures EW threat simulators are generally the accepted test tool, but can sometimes be slow to respond to newly identified threats. 9 10/16/2012

9 Electronic Warfare Threat Simulators Complex multi-emitter simulators are well suited for EW testing in a complex electromagnetic environment, however: Can be overkill for simple RWR threat identification testing Can be costly and time consuming to reprogram, as new threats are added /16/2012

10 Need: Simplified EW Threat Simulation RWR testing and verification requires: Ability to quickly verify RWR performance for newly programmed threats Simple set up Minimum programming time Lower cost solution, as opposed to large multi-emitter simulators A threat simulator must be able to correctly simulate: Radar pulse characteristics Modulation on pulse Correct RF Frequency and spectral characteristics Correct signal amplitude levels Radar antenna patterns Antenna scanning 11 10/16/2012

11 Agilent N7620B Signal Studio For Pulse Building Software I Q 12 10/16/2012

12 Signal Studio for Pulse Building N7620B software Provides: A simple graphical user interface Pulse repetition interval patterns Pulse width timing patterns Modulation on pulse (MOP) Antenna radiation patterns Antenna scanning patterns Import and Export CSV files defining waveform generation /16/2012

13 Pulse Timing / Pattern Controls Pulse Repetition Interval Constant (none) Gaussian Jitter Uniform Jitter U shaped Jitter Linear Ramp Stepped Staggered Bursted Saw tooth Wobbulation Sinusoidal Wobbulation Triangle Wobbulation Pulse Width Patterns Constant Gaussian Jitter Uniform Jitter Linear Ramp Stepped MOP Barker Code Frank Code FM Chirp User defined 14 10/16/2012

14 Example of Staggered PRI PRI Time 15 10/16/2012

15 Supported Antenna Parameters Antenna Scanning Modes Custom Circular Conical Bidirectional Sector Unidirectional Sector Bidirectional Raster Unidirectional Raster Antenna Properties Azimuth 3 db Beam Width Elevation 3 db Beam Width Null depth - db Antenna Radiation Patterns Blackman Hamming Hanning Rectangular 3 Term Cosine1 Cosine2 Cosine3 Cosine4 Cosine5 Programmable 16 10/16/2012

16 Example of Antenna Scan Patterns 17 10/16/2012

17 Bidirectional Raster Antenna Scan 18 10/16/2012

18 Scenario Data Base Import/Export Threat Data Bases EWIR Pulse Builder Scenario.CSV File KILTING Next Gen /16/2012

19 Scenario Data Base Import & Exporting CSV Comma Delimited File created in Excel Scenario Name Source Parameters Pulse Envelope properties tr, tf, PW Pulse Width Patterns PRI Patterns Modulation on Pulse Properties Chirp, Barker, FSK, etc Antenna Scanning Type Antenna Radiation Type Antenna Beam Width AZ, El Antenna Null Depth Receiver Location 20 10/16/2012

20 Summary Radar Warning Receiver programming must be kept up to date with current threat data Testing is required to ensure the RWR responds to newly programmed threats Commercial off-the-shelf test equipment can provide a cost effective method to verify RWR performance New software tools can greatly simplify the development complex radar and EW simulations /16/2012