16.1 Introduction

The users of ELINT are primarily concerned with emitter identification (as in radar warning receivers), and with countering the emitter once it is recognized. Other uses include driving simulation systems used in training. For identification, the interceptor makes use of the ELINT parameters and the parameter limits expected for each type of emitter as discussed in Chapter 15. For designing an electronic attack to counter an emitter, it is necessary to have more detailed information about how the radar operates and especially how the receiver processes signals. This is because only receivers are jammed not transmitters. For this, detailed technical information is needed and not all of it is available from ELINT. This gives rise to dividing the information into observed and assessed categories. Observed data is largely from ELINT. Assessed data is an analyst s best estimate of how the system performs based on all information available at the time and including engineering calculations and the limitations due to target motion.

ELINT can be divided into technical information (TECHELINT) and operational information (OPELINT) as shown in Figure 16.1. This book is mainly concerned with technical ELINT. But note that emitter location, an OPELINT parameter, makes use of highly technical signal processing techniques. Of course, data files of non-ELINT data are also maintained and used. SIGINT other than ELINT includes the data listed in Figure 16.2. Non-SIGINT intelligence files are listed in Figure 16.3.