A radar cross-section is a way of measuring how noticeable is an object from a radar. That's why it's also called an electromagnetic signature. So, a high radar cross-section for an object means that it is easy to be seen in radars.
Any object, including fast fighters or enormous military ships, reflects some of the waves back to the source, the radar. The factors that affect the reflection percentage of the object are these:
- the material that the object is built of
- the size of the target in relation to the wavelength of the radar
- the total size of the target
- the incident angle (the angle at which the radar waves hit the target – the angle is, depending on the shape of the target and the orientation of the radar)
- the reflected angle (the angle in which the radar waves come back from the target – the angle is depending on the incident angle)
- the polarization of the radiation (transmitted and received) in relation to the target orientation
Even if the power of the radar and the distance between the radar and the target are important factors in the tracking targets, they are not factors that affect the calculation of the radar cross-section, as the radar cross-section is a property of the reflectiveness of the target.
The interesting part is that stealth weapons like aircraft have design features that reduce the radar cross-section, a fact that results in stealth technology. On contrary, passenger airplanes have a high radar cross-section in order to be tracked easily.
The technology of this field is really important for stealth technology, especially for aircraft and ballistic missiles. The research of each nation about this science field is critically confidential and rarely revealed.
