Process for mapping multiple-bounce ghosting artifacts from radar imaging data
View Patent ↗Described herein are frequency-domain back-projection processes for forming spotlight synthetic aperture radar (“SAR”) images that are not corrupted by the effects of multiple-bounce ghosting artifacts. These processes give an approximately exact reconstruction of the multiple bounce reflectivity function (MBRF) ƒ(x,y,γ). Specifically, the evaluation of ƒ(x,y,γ) in the γ=0 plane gives an approximately exact reconstruction of the true object scattering centers which is uncorrupted by multiple-bounce contributions to the phase history data G(ξ,θ). In addition, the non-zero dependence of ƒ(x,y,γ) upon the MB coordinate γ can be used to facilitate the identification of features-interest within the imaged region.
1. A process for analyzing radar scattering data from an object-of-interest comprising:
receiving radar scattering data from the object-of-interest, the object-of-interest includes at least two scattering points;
identifying the radar scattering data as containing multiple-bounce information resulting from reflection off of the at least two scattering points, wherein the radar scattering data containing multiple-bounce information further includes measured phase history data; and
imaging the object-of-interest using the multiple-bounce information.
2. The process of claim 1 , further comprising:
separating the identified radar scattering data.
3. The process of claim 2 , the imaging the object-of-interest using the multiple-bounce information comprises:
imaging the object-of-interest using the separated radar scattering data.
4. The process of claim 2 , the separating the radar scattering data comprises:
reconstructing the at least two scattering points according to the radar scattering data.
5. The process of claim 4 , the reconstructing the at least two scattering points comprises:
reconstructing a multiple bounce reflectivity function (“MBRF”) ƒ(x,y,γ) for each of the at least two scattering points based on measured phase history data as described according to the equation
G
(
ξ
,
θ
)
≡
∫
-
∞
∞
ⅆ
x
∫
-
∞
∞
ⅆ
y
∫
-
∞
∞
ⅆ
γ
f
(
x
,
y
,
γ
)
exp
(
-
j
2
π
[
x
cos
(
θ
)
+
y
sin
(
θ
)
+
γ
]
ξ
)
,
wherein ξ represents spatial frequency and θ represents measurement angle.
6. The process of claim 4 , further comprising:
transmitting at a first location a radar signal toward the object-of-interest; and
the receiving radar scattering data includes receiving at a second location the radar scattering data from a reflection of the radar signal, the second location is different from the first location.
7. The process of claim 6 , further comprising:
reconstructing a multiple bounce reflectivity function (“MBRF”) ƒ(x,y,γ) for each of the at least two scattering points based on measured phase history data as described according to the equation
G
(
ξ
′
,
θ
′
)
≡
∫
-
∞
∞
ⅆ
x
∫
-
∞
∞
ⅆ
y
∫
-
∞
∞
ⅆ
γ
f
(
x
,
y
,
γ
)
exp
(
-
j
2
π
[
x
cos
(
θ
′
)
+
y
sin
(
θ
′
)
+
γ
]
ξ
′
)
,
wherein ξ′ represents spatial frequency which is scaled by a factor cos(β/2), β being equal to an angle between the first location and the second location, and θ′ is a bisector angle between the angle β.
8. The process of claim 1 , the at least two scattering points include at least three scattering points, two of the at least three scattering points lie on a first plane and one of the at least three scattering points lie on a second plane.
9. The process of claim 8 , the first plane and the second plane are different planes.