What’s the difference between an "Area" and a "Point" munition?
First, let’s dispel the idea that “area” vs. “point” implies something about the precision of the munition. It doesn’t--it implies something about the area of the effect of the munition at detonation. You can have a precise area munition (some CBUs); and you can have an imprecise point munition (some dumb bombs). Thus you can have both types in both the SSPD and GPS SSPD tables. The difference is in how adjudication is conducted.
Point: A (stick of) point munition(s) is designed to adjudicate a single resource (ex. one tank). During execution the adjudicator will apply the (GPS, if appropriate) SSPD (single stick probability of damage) against a single resource item, regardless of the size of the Standard Target. There will be no “collateral damage” effects against other resources.
Area: A (stick of) area munition(s) will be applied against a Standard Target. Standard targets are user-defined (ex. 4 tanks). During execution, the adjudicator will apply the (GPS) SSPD against each of the resources in the standard target individually. An SSPD of 0.5 doesn’t necessarily mean that 2 of the 4 tanks will be killed; a 0.5 SSPD against 4 tanks could result in anywhere from 0 to 4 killed. NOTE: The documentation in Vol 3 (Para 5.6) suggests that there is deterministic adjudication against non-fixed targets (see pseudo-code below). That was from an older version of the model; all A2G adjudication is now stochastic.
If the Condition of the StandardTarget is ‘FIXED’ then
Determine attrition stochastically with random draws against the SSPD for each element in the StandardTarget
Otherwise
Determine attrition deterministically by multiplying the SSPD by the number of elements in the StandardTarget
Additionally, an area munition can have “collateral” (or “unintended target”) effects. The ratio of each Standard Target’s area to the total area of all of the target BSE’s FCPs (fire concentration points) is calculated. For example, if the Standard Target X is 5% of the total area of all of the target BSE’s FCPs, then a random number draw of 0.05 or less means that Standard Target X will be adjudicated as an “unintended target” of the area munition. This is repeated for all of the Standard Targets for the target BSE.
Note: All resources are assumed to be located in an FCP. For example, a battalion normally has 3 FCP, representing company-level formations or groupings. Even fixed BSEs (such as installations) have at least on FCP, where the resources are assumed to be evenly distributed.
Why does this matter?
Each munition’s SSPD against a Standard Target is derived from a data generator (ex. WEPS). Since the inputs into WEPS are based upon the aircraft, weather band (non-GPS), munition, stick size, Standard Target element and area, and whether the munition is being employed as an area or point munition, the SSPD generated is dependent upon those factors. While the model allows users to check or uncheck the “Is Area Munition”, changing that value may negate the assumptions which went into the SSPD. Since each munition/Standard Target pairing has a single SSPD, changing the “Is Area Munition” without changing the SSPD is inappropriate.
If users want to be able to use the same munition/Standard Target pairing with both area and point munition designation, it is recommended that users create a separate munition ID for each case (area vs. point).