Radar cross-section pattern
rcsSignature creates a radar cross-section (RCS) signature object. You can
use this object to model an angle-dependent and frequency-dependent radar cross-section
pattern. The radar cross-section determines the intensity of reflected radar signal power from
a target. The object models only non-polarized signals.
rcssig = rcsSignature
rcsSignature object with default property values.
sets object properties using one or more
rcssig = rcsSignature(
Name,Value pair arguments.
Name is a property name and
Value is the
Name must appear inside single quotes
''). You can specify several name-value pair arguments in any order
Name1,Value1,...,NameN,ValueN. Any unspecified properties take
You can only set property values of
rcsSignature when constructing the
object. The property values are not changeable after construction.
Pattern— Sampled radar cross-section pattern
[10 10; 10 10](default) | Q-by-P real-valued matrix | Q-by-P-by-K real-valued array
Sampled radar cross-section (RCS) pattern, specified as a scalar, a Q-by-P real-valued matrix, or a Q-by-P-by-K real-valued array. The pattern is an array of RCS values defined on a grid of elevation angles, azimuth angles, and frequencies. Azimuth and elevation are defined in the body frame of the target.
Q is the number of RCS samples in elevation.
P is the number of RCS samples in azimuth.
K is the number of RCS samples in frequency.
Q, P, and K usually match
the length of the vectors defined in the
respectively, with these exceptions:
To model an RCS pattern for an elevation cut (constant azimuth), you can
specify the RCS pattern as a Q-by-1 vector or a
1-by-Q-by-K matrix. Then, the elevation
vector specified in the
Elevation property must have length
To model an RCS pattern for an azimuth cut (constant elevation), you can
specify the RCS pattern as a 1-by-P vector or a
1-by-P-by-K matrix. Then, the azimuth
vector specified in the
Azimuth property must have length
To model an RCS pattern for one frequency, you can specify the RCS pattern as
a Q-by-P matrix. Then, the frequency vector
specified in the
Frequency property must have length
Azimuth— Azimuth angles
[-180 180](default) | length-P real-valued vector
Azimuth angles used to define the angular coordinates of each column of the matrix
or array, specified by the
Pattern property. Specify the azimuth
angles as a length-P vector. P must be greater
than two. Angle units are in degrees.
Elevation— Elevation angles
[-90 90](default) | length-Q real-valued vector
Elevation angles used to define the coordinates of each row of the matrix or array,
specified by the
Pattern property. Specify the elevation angles as
a length-Q vector. Q must be greater than two.
Angle units are in degrees.
Frequency— Pattern frequencies
[0 1e20](default) | K-element vector of positive scalars
Frequencies used to define the applicable RCS for each page of the
Pattern property, specified as a K-element
vector of positive scalars. K is the number of RCS samples in
frequency. K must be no less than two. Frequency units are in
Radar cross-section at specified angle and frequency
Specify the radar cross-section (RCS) of a triaxial ellipsoid and plot RCS values along an azimuth cut.
Specify the lengths of the axes of the ellipsoid. Units are in meters.
a = 0.15; b = 0.20; c = 0.95;
Create an RCS array. Specify the range of azimuth and elevation angles over which RCS is defined. Then, use an analytical model to compute the radar cross-section of the ellipsoid. Create an image of the RCS.
az = [-180:1:180]; el = [-90:1:90]; rcs = rcs_ellipsoid(a,b,c,az,el); rcsdb = 10*log10(rcs); imagesc(az,el,rcsdb) title('Radar Cross-Section') xlabel('Azimuth (deg)') ylabel('Elevation (deg)') colorbar
rcsSignature object and plot an elevation cut at azimuth.
rcssig = rcsSignature('Pattern',rcsdb,'Azimuth',az,'Elevation',el,'Frequency',[300e6 300e6]); rcsdb1 = value(rcssig,30,el,300e6); plot(el,rcsdb1) grid title('Elevation Profile of Radar Cross-Section') xlabel('Elevation (deg)') ylabel('RCS (dBsm)')
function rcs = rcs_ellipsoid(a,b,c,az,el) sinaz = sind(az); cosaz = cosd(az); sintheta = sind(90 - el); costheta = cosd(90 - el); denom = (a^2*(sintheta'.^2)*cosaz.^2 + b^2*(sintheta'.^2)*sinaz.^2 + c^2*(costheta'.^2)*ones(size(cosaz))).^2; rcs = (pi*a^2*b^2*c^2)./denom; end
 Richards, Mark A. Fundamentals of Radar Signal Processing. New York, McGraw-Hill, 2005.