JED - February 2015 - (Page 42)

EW 101 Independently Maneuvering Decoys Radar Decoys - Part 8 By Dave Adamy I ndependently maneuvering decoys are used to protect both aircraft and DECOYS ships. Like expendable and towed TARGET decoys, they provide attractive false targets for hostile radars at locations away from the radar's intended targets. However, because this type of decoy maneuvers, it has the advantage that it can be placed in an optimum location and moved as required to provide optimum deception of the enemy radar (and hence optimum miss distance by an enemy misFigure 1: Independently maneuvered decoys can imitate the motion of targets to make it more sile guided by that radar). These decoys difficult for a radar to targets. can be maneuvered by command or can Figure 1: Independently distinguish them from can imitate the motion of targets to maneuvered decoys follow preprogrammed trajectories away make it more difficult for a radar totargets, butthem from targets. be close enough to require actual distinguish if not, they should from their launching locations. significant processing by the radar to reject decoys. The Journal of Electronic Defense | February 2015 42 SATURATION DECOYS DETECTION DECOYS In the September 2014 "EW 101" column, we discussed saturation decoys, which force a hostile radar to either attack a very large number of targets or to distinguish actual targets from decoys. Independently-maneuvering decoys can perform this mission ideally, since they can move in a realistic imitation of a radar's intended target as shown in Figure 1. However, they can avoid locations that would place an enemy missile in a position to reacquire the target or acquire an alternate friendly ship or aircraft. Ideally, decoys would be indistinguishable from Detection decoys, also discussed in the September 2014 column, must by their nature, maneuver independently. They can be payloads of unmanned aerial vehicles (UAVs) or can be air launched decoys which fly into protected enemy airspace well ahead of any controlling or attack aircraft. The decoy payloads must transmit signals close enough to actual skin returns to be accepted as real, high-priority targets by acquisition radars. Note that sophisticated modern radars may apply significant sophistication to their analysis of signals to differentiate between decoys and real targets. Thus, the decoy payloads must also be sophisticated. You may want to review the series of "EW 101" articles from October 2013 to JanuIndividual Skin Return ary 2014 which cover the applications of TARGET Digital RF Memories (DRFMs). Figure 2 compares a real skin return pulse from an idealized pulse. The flight paths of these decoy platforms must also accurately imitate atCombined Returns tacking aircraft. If successful, a detection decoy will cause an integrated air defense system to activate tracking radars. Then, when the tracking radar is active, it can be located and bombed or attacked by a Figure 2: A radar receives several skin returns from different parts of the target. Each return has a radar homing missile. different amplitude and is delayed by its individual round trip path length. Figure 2: A radar receives several skin returns from different parts of the target. Each return has a different amplitude and is delayed by its individual round trip path length.

Table of Contents for the Digital Edition of JED - February 2015

The View From Here
Conferences Calendar
Courses Calendar
From the President
The Monitor
World Report
Maritime SIGINT: Shipborne Ears for the “Five Eyes”
Technology Survey: Analog-to-Digital Converters
EW 101
AOC News
Index of Advertisers
JED Quick Look

JED - February 2015