Radar cross section is the measure of a target's ability to reflect radar signals in the direction of the radar receiver, i.e. it is a measure of the ratio of backscatter power per steradian (unit solid angle) in the direction of the radar (from the target)
to the power density that is intercepted by the target.
The RCS of a target can be viewed as a comparison of the strength of the reflected signal from a target to the reflected signal from a perfectly smooth sphere of cross sectional area of 1 m2 as shown in Figure 1 .
Concept of Radar Cross Section - RF CafeThe conceptual definition of RCS includes the fact that not all of the radiated energy falls on the target. A target’s RCS (σ) is most easily visualized as the product of three factors:
σ = Projected cross section x Reflectivity x Directivity .
RCS(σ) is used in Section 4-4 for an equation representing power reradiated from the target.
Reflectivity: The percent of intercepted power reradiated (scattered) by the target.