The applet displays the protection zones provided by an ECM jammer when operating in both the self-protect and area-defense modes.
The first plot option in the drop-down menu is the protection zone (to the right of the blue curve) for the self-defense/point defense jammer mounted on a platform of radar cross section equal to the Target RCS scrollbar setting. Jammer antenna pointing direction is broadside as shown and the protection curve assumes that the incoming radar antenna from any cross/down-range position points directly at the ECM location. The Jammer Beamwidth is important when countering multiple threat radars off the jammer antenna boresight.
The second menu option, shows the regions ( to the left or inside the blue curve) where targets up to a selected target RCS are covered in the area defense role. The option also covers the case when the radar is offset (Radar Offset scrollbar) away from broadside where the jammer antenna continues to track the radar platform direction.
Antenna beam shape is a modified sin(x)/x pattern with –24dB first sidelobes and lowest sidelobe related to the beamwidth (bw in degrees) by the function; –55 dB+10log(bw). The antenna sidelobe levels can be adjusted about this level using the Antenna S/L Adjust scrollbar.
Moving the mouse in the range/cross-range space displays the point coordinates.
The display automatically scales to the geometry specified in the range text boxes.

User Notes:
For point defense, careful selection of jammer antenna beamwidth enables tactical compromises between wide field-of-cover against multiple threats and minimum burn-through against high priority threats over narrower fields-of-view. In this role, the alignment accuracy of the ECM antenna need only be within its 3dB beamwidth.
For area defense, a high gain, high ERP, jammer antenna provides maximum area protection against emitters and good burn-through of radar sidelobes. Conversely, improving the radar antenna sidelobe performance can seriously reduce this advantage. Radar Down-Range 'from' value can be set negative to view the area protected behind the ECM.
The jammer beamwidth is a factor in the achieved ERP, but must also be able to encompass and track the radar platform. Multithreat capability is limited to emitters within this sector, which again defines the ECM alignment accuracy.
A high jam-to-signal ratio allows for some antenna and frequency alignment error whilst still ensuring that the jamming signal received by the radar exceeds the target return.