JED - October 2011 - (Page 51)
PORTABLE AND FLIGHTLINE EW TESTERS
By Ollie Holt
his JED survey examines equipment that supports field or flightline testing of EW systems covering the RF, UV, IR and laser spectrum. These types of simulators typically differ from laboratory simulators in a few key ways. They must be designed for portability and ease of use in an open or outdoor environment. They are used to test an EW system – a radar warning receiver (RWR), missile warning system (MWS), laser warning system (LWS), improvised explosive device (IED) jammer, etc. – that is installed on an aircraft, ship or ground vehicle and confirm the EW system is working properly. Finally, they must be able to simulate one or more threats with enough fidelity to activate the EW system. Threat signals may reach the EW system via free space radiation, by fitting a coupler (or RF hat) over an antenna, or directly injecting the threat signal into the EW system. RF EW simulators vary from simple signal generators that can simulate a single RF pulse or CW signal to a combination of signal generators that, under computer control, can simulate multiple RF threats following a preprogrammed scenario. In the UV/IR spectrum, the simulators can simulate the launch of a missile, as well as the fly out of that missile. A laser threat simulator can mimic the signals from laser rangefinders, beamriders and designators. As multispectral EW suites become more common on platforms such as helicopters, some of the simulators can operate in more than one spectrum to stimulate the various EW sensors. A new category of simulators tests IED jammers. Three companies – two from the US and one from Israel – currently serve this growing market. The survey also includes several countermeasures dispenser system (CMDS) testers. These devices are used to check that the dispensers will eject the correct chaff or flare countermeasures in the proper sequence in response to different types of threats.
In the survey table, the second column defines the types of EW systems or sensors that are stimulated by the simulator device. The third column identifies the operational spectrum of the simulator. Some operate only in the RF or IR portion of the electromagnetic spectrum, while others operate in multiple portions of the spectrum. The operational spectrum or spectrums define operational range within the spectrum where threat signals can be simulated. RWR testing can be done via free space (radiated) RF energy, an antenna coupler, or direct injection into the system. For missile warners and laser warning systems, free space radiation is the typical method of signal injection. The “Number of Signals” column specifies the total number of different threat signals the simulator can be programmed to emulate. The next column, which is the “Number of Simultaneous Signals,” tells you how many signals the simulator can create at a single time. This allows the simulator to create a dense environment of more than a single threat. Typically, for pulsed RF signal simulations, more than one threat can be simulated with a single RF signal generator, but with some dropped pulses. Most multi-signal simulations will attempt to simulate all the pulses of a signal but will have to drop some pulses because of pulse-on-pulse conditions. The “Programmable” column defines if the system is user programmable or if it is designed to only generate a specific signal type that cannot be changed by the user. Most of the systems listed can be programmed within the device or by connecting to a portable computer. Some already come supplied with some pre-programmed threat simulations. This month’s survey includes a wide variety of portable EW testers from 15 manufacturers. Next month’s JED will include a survey of receivers and tuners for COMINT/DF applications.
The Journal of Electronic Defense | October 2011
Table of Contents for the Digital Edition of JED - October 2011
The View From Here
From the President
RF EW Program Forecast
EW Ideas and Innovation
Technology Survey: Portable and Flightline EW Testers
Index of Advertisers
JED Quick Look
JED - October 2011