On the evaluation of scattered power and radar cross section of a space vehicle in warm plasma.

The scattering of electromagnetic waves and plasma waves by a space vehicle, excited by a ground source, in an isotropic warm plasma is studied. By considering the propagation constant for the induced current and charge on the vehicle due to ground excitation to be general, expressions for scattered power and radar cross section of the vehicle are obtained and the effect of generation of electroacoustic waves by the vehicle on the scattered power and radar cross section is discussed. By giving three different values to the general propagation constant, different theoretical curves for the radar cross section are obtained and compared with the available experimental graphs, and the possibility of neglecting the presence of current having propagation constant equal to <bgr><SUBp> is explored. The power re-radiated by the space vehicle is also computed and it is shown that the behavior of power re-radiated by a cylindrical space vehicle is similar to the power radiated by a thin cylindrical antenna in plasma.
7. Discussions and concluding remarks
A similar problem has been considered by Seshadri (1964), but his expressions for the scattered power are in the form of infinite series. Using a propagation constant equal to that of the EM wave in plasma, Chen (1965) has determined induced current and charge on the surface of a space vehicle and their effect on the radar cross sections of the vehicle. It is pointed out here that the expressions for scattered power W <SUBe> and W <SUBp> given in (35) and (38) do not involve any approximation in the evaluation of integrals. The phase propagation constant <Bgr> is general and can be put equal to <Bgr><SUB0>, <Bgr><SUBe>, <Bgr><SUBp> or any other value determined experimentally. The corresponding values for W <SUBe> and W <SUBp> can then be found out. Equations (41) and (42), in which the functions of Si, Ci and Cin are approximated for very large values of c/v<SUB0>=10<SUP3>, are for the case when... [ABSTRACT FROM AUTHOR]