===== How does jamming a SAM site work? =====

First, a reminder that in JAS there are two types of jamming: The ability of an aircraft to jam the radar associated with a SAM site (to reduce the radar’s range), and the ability to jam the GPS guidance package on a munition (reducing the accuracy of the precision munition). Here, we’re discussing the former.

Jamming effectiveness is heavily dependent on the distance of the jammer from the AD site’s radar. Jamming curve data is provided in adjudicationData » SurfaceToAirAdjudicationData » Radar » [Specific Radar] » JamCurves » Standoff » [Specific Jammer] (the AIR_DEFENSE_JAM_STANDOFF table). Available fields are STANDOFF_JAMMER_RNG (the jammer’s distance from the AD site’s radar) and JAMMER_1SQM_BURNTHRU_RNG (the distance at which the radar is able to burn through the jamming enough to see a 1 m2 RCS target. Let’s review a fictitious example:

^STANDOFF_JAMMER_RNG    ^JAMMER_1SQM_BURNTHRU_RNG^
|0                      |0|
|5000                   |750                    |
|10000                  |2000                   |
|20000                  |5000                   |
|30000                  |15000                  |
|40000                  |30000                  |
|50000                  |50000                  |

{{:jas:samjamming.jpg|}}

In this example, at jammer standoff range of 5,000 m, the AD radar has a range of only 750 m, but as jammer stands off at 50,000 m, it has no effect on the AD radar’s range (still 50,000 m). Essentially, in JAS (as in real life) unless the jammer gets close enough to the radar it is trying to jam, it will have very little effectiveness, so place the SEAD points appropriately. This, of course, is complicated by overlapping radars.

In real life, many jammers are directional, where the jammer aircraft is placed on an appropriate bearing from the radar, and with the aircraft’s nose oriented relative to the radar. This mission-level degree of detail is not necessary in JAS. When the user places a JamSEADStandoff point in relation to a radar, the jammer affects all radars within its implicit range.

Additional notes:

    *
      Only S2A acquisition (AQ) & fire control (FC) radars are affected by jamming
    *
      The jammer has no explicit range; its “range” is reflected in how it affects the radar’s range
    *
      The jammer’s effectiveness (jammed and unjammed detection ranges) is instrumented in ADJ S2A JAMSEAD EFFECTS
    *
      Escort Jamming has not been implemented yet, so escort jamming data in adjudicationData » SurfaceToAirAdjudicationData » Radar » [Specific Radar] » JamCurves » Standoff is unused

