JED - December 2010 - (Page 31)

TECHNOLOGY SURVEY EW Simulators for Laboratory Testing By Ollie Holt T his month’s technology survey takes a look at EW simulators for supporting integration and lab testing of EW systems covering the RF, UV, IR and laser spectra. Testing and evaluation of EW systems is about as challenging as building an EW system. The task of verifying the specified operation of an EW system requires being able to simulate the operational environment, including threats, friendly emitters and other signals emitted by neutral commercial and government sources. This requires the generation of the signal density and signal dynamics observed by the EW platform. The threat system dynamics include spatial change due to platform movement and changes in the operational modes of the threat systems as the environment changes (missiles get launched and RF signals change modes and/or frequency). Because of the high cost of providing a real operational environment and the large spatial area which this type of range would require, such resources are few and usually unavailable for initial integration and test. These resources are reserved for final acceptance testing and training. Because of the cost and availability of these resources, EW simulators that can simulate one or many threat signals and include both spatial dynamics and signal mode changes are required. These simulators provide a lower cost method of integration and initial system testing. 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 moving spatially following a preprogrammed scenario. In the past, most EW simulators were developed for airborne EW scenarios. With the growing IED threat, however, more companies are touting the communications simulation capabilities of their systems. In the UV/IR spectrum, the simulators can simulate the launch of a missile and the flyout of that missile, including modifying plume spectrum and intensity as the missile moves through a predetermined flight path. A laser threat simulator can vary the signals modula- tion, PRF and pulse width as it follows a predetermined scenario. As the number of signals and spatial dynamics of each signal become more complex, the cost of these EW simulator systems goes up, and it can go into the tens of millions of dollars. This survey includes RF, UV, IR and laser simulators. Some companies had some of each type. The results were grouped into simulators of a similar type for ease of comparison. The first column identifies the company that developed the simulator and the simulator model number. The next column defines the purpose of the simulator. It can be seen that the main purpose of the simulators is to emulate some or all of the identifiable components of a threat signal. That component could be the RF signal pattern, the missile plume or the laser signal pattern. Some of the higher-fidelity systems generate multi-spectral signals to simulate all the various components of a threat system. The spectrum column identifies the operational spectrum of the simulator. Some are just RF with the RF frequencies ranges defined while others operate in the UV, IR or laser spectra. The operational spectrum defines operational range within the spectrum where the threat signals can be simulated. If the threat to be simulated lies outside the operational range of the simulator it cannot emulate the threat. The “RF Out” column defines the method of injecting the signal into the EW system to be tested or evaluated. For the RF systems the simplest method is either a direct connection to the antenna ports or with a coupler (also known as an “RF hat”) to radiate into the antenna. For RF systems that are also simulating spatial characteristics of the RF signal, each antenna operating at the signal’s RF frequency has to be stimulated with the simulated waveform if direct antenna connection or couplers are used. If free space (radiated) RF is used, then the spatial component is created by just the placement of the radiated signal. For UV, IR and laser systems, free space radiation is the method of signal injection. Again the spatial component for UV, IR or laser signals is controlled by the radiator’s location and signal amplitude. The Journal of Electronic Defense | December 2010 31

Table of Contents for the Digital Edition of JED - December 2010

JED - December 2010
The View From Here
Conferences Calendar
Courses Calendar
From the President
The Monitor
Washington Report
World Report
EW Battle Management
Technology Survey: EW Simulators
2011 EW/SIGINT Resource Guide
EW 101
AOC News
Index of Advertisers
JED Quick Look

JED - December 2010