44
3 Radar Targets and Its Reflecting Properties
Table 3.1 RCS average
values for different aerial, sea
and ground radar targets
Target type
RCS, m 2
Cruiser
15,000
Commercial sea craft
150…15,000
Submarine
100
Transport aircraft
50
Long-range aircraft
50
Long-range passenger airplane
20–25
Medium-range passenger airplane
15–20
Two-propeller small passenger airplane
20–25
Single-rotor light aircraft
5–10
Helicopter
1–3
Stealth aircraft
0.1–1
Cruise missile
0.01–0.03
where d
2
A is dispersion of RCS of j-target.
As we can see, even in simplest problem, we have to inevitably deal with statistical
approach to calculation of RCS.
Table 3.1 shows RCS average values for different target types.
The calculation technique of complex body RCS is given bellow.
The sequence of approximate calculation of complex body RCS is composed of
the following stages:
• body division into elements;
• its surface segments approximation by simple bodies;
• calculation of its bodies RCS and results integrating for receiving of RCS value
of a body as a whole.
Body division into elements is carried out on the base of its structural features
and physical representation on reflective capability of different surface segments. For
example, the elements of the aircraft are engines, wings, antenna under radiotransparent radome, fuselage, cockpit, tail assembly. In its turn, on each of the mentioned
segments, there could be more selected small parts that are segments of local reflection. It is obvious that an amount of selected elements, joined into a table, depends
on direction of observing. So, complex body elements are defined in some (little)
sector of observation angles: For another sector, there will be different table.
At approximation of selected element by a simple body, it is guided not only
by requirements of geometric similarity as much as by aiming to provide value
coincidence of element RCS and its approximated simple body in the examined
sector of observation angles. A part of elements is not modeled by geometrically
similar bodies, an equivalent to it in RCS disks, angular constructions and other
bodies in observation angles sector which are selected for them.
Another part of moments during modeling simplifies and is approximated by
simple bodies.
3 Radar Targets and Its Reflecting Properties
Table 3.1 RCS average
values for different aerial, sea
and ground radar targets
Target type
RCS, m 2
Cruiser
15,000
Commercial sea craft
150…15,000
Submarine
100
Transport aircraft
50
Long-range aircraft
50
Long-range passenger airplane
20–25
Medium-range passenger airplane
15–20
Two-propeller small passenger airplane
20–25
Single-rotor light aircraft
5–10
Helicopter
1–3
Stealth aircraft
0.1–1
Cruise missile
0.01–0.03
where d
2
A is dispersion of RCS of j-target.
As we can see, even in simplest problem, we have to inevitably deal with statistical
approach to calculation of RCS.
Table 3.1 shows RCS average values for different target types.
The calculation technique of complex body RCS is given bellow.
The sequence of approximate calculation of complex body RCS is composed of
the following stages:
• body division into elements;
• its surface segments approximation by simple bodies;
• calculation of its bodies RCS and results integrating for receiving of RCS value
of a body as a whole.
Body division into elements is carried out on the base of its structural features
and physical representation on reflective capability of different surface segments. For
example, the elements of the aircraft are engines, wings, antenna under radiotransparent radome, fuselage, cockpit, tail assembly. In its turn, on each of the mentioned
segments, there could be more selected small parts that are segments of local reflection. It is obvious that an amount of selected elements, joined into a table, depends
on direction of observing. So, complex body elements are defined in some (little)
sector of observation angles: For another sector, there will be different table.
At approximation of selected element by a simple body, it is guided not only
by requirements of geometric similarity as much as by aiming to provide value
coincidence of element RCS and its approximated simple body in the examined
sector of observation angles. A part of elements is not modeled by geometrically
similar bodies, an equivalent to it in RCS disks, angular constructions and other
bodies in observation angles sector which are selected for them.
Another part of moments during modeling simplifies and is approximated by
simple bodies.