https://en.wikipedia.org/wiki/Radar_cross-section#Factors_that_affect_RCS
(also called the normalized radar cross-section or backscatter coefficient) σ0 ("sigma naught"), which is the average radar cross-section of a set of objects per unit area:
- _ xml_ns="http://www.w3.org/1998/Math/MathML">σ 0 = ⟨ R C S i A i ⟩ {\displaystyle \sigma ^{0}=\left\langle {{RCS_{i}} \over {A_{i}}}\right\rangle }
![\sigma ^{0}=\left\langle {{RCS_{i}} \over {A_{i}}}\right\rangle](https://wikimedia.org/api/rest_v1/media/math/render/svg/d0b42a614058fc002c8a581449895436b35e94ce)
where:
- RCSi is the radar cross-section of a particular object, and
- Ai is the area on the ground associated with that object.[1]
_ xml_ns="http://www.w3.org/1998/Math/MathML">P r = P t G t 4 π r 2 σ 1 4 π r 2 A e f f {\displaystyle P_{r}={{P_{t}G_{t}} \over {4\pi r^{2}}}\sigma {{1} \over {4\pi r^{2}}}A_{\mathrm {eff} }} ![P_{r}={{P_{t}G_{t}} \over {4\pi r^{2}}}\sigma {{1} \over {4\pi r^{2}}}A_{\mathrm {eff} }](https://wikimedia.org/api/rest_v1/media/math/render/svg/182e7696caa0c1e8c40f34fbd2451bd0eee1606f)
where
- _ xml_ns="http://www.w3.org/1998/Math/MathML">P t {\displaystyle P_{t}}
= power transmitted by the radar (watts)
- _ xml_ns="http://www.w3.org/1998/Math/MathML">G t {\displaystyle G_{t}}
= gain of the radar transmit antenna (dimensionless)
- _ xml_ns="http://www.w3.org/1998/Math/MathML">r {\displaystyle r}
= distance from the radar to the target (meters)
- _ xml_ns="http://www.w3.org/1998/Math/MathML">σ {\displaystyle \sigma }
= radar cross-section of the target (meters squared)
- _ xml_ns="http://www.w3.org/1998/Math/MathML">A e f f {\displaystyle A_{\mathrm {eff} }}
= effective area of the radar receiving antenna (meters squared)
- _ xml_ns="http://www.w3.org/1998/Math/MathML">P r {\displaystyle P_{r}}
= power received back from the target by the radar (watts)
RCS를 계산하는 방법은 없고(링크에), RCS가 대략 어떤것에 관련되는지와
그리고, A26기의 실험결과가 있네요.
그리고, RCS가 복잡한 방향성의 함수라서 σ 라는 nomalized RCS를 정의해서 사용한답니다.
(표준 RCS값 정도...)
r이 레이다와 타겟과의 거리이고, 구하고자 하는 값이 r 값이면....
옮겨서 계산하면 σ와의 관계식을 알수가 있죠.