  In this paper, the general radar measurement probfilems of determining range,
Doppler frequency and scatteringproperties parameters are investigated from the
viewpoint of Shannons information theory. We adopt the mutual information to
evaluate the accuracy of the classification and estimation. The range-Doppler
information is examined under the condition that the target is of radial
velocity. Its asymptotic upper bound and the corresponding entropy error (EE)
are further formulated theoretically. Additionally, the Doppler scattering
information induced by targets random motion characteristics is discussed. From
the derivation, it is concluded that the Doppler scattering information depends
on the eigenvalues of the target scattering correlation matrix. Especially in
the case where the pulse interval is larger than targets coherence time, we can
find that the formula of the Doppler scattering information is similar to
Shannons channel capacity equation, indicating the inherent consistency between
the communication theory and radar field. Numerical simulations of these
information contents are presented to confirm our theoretical observations. The
relationship between the information content and signal-to-noise ratio (SNR)
reflects the changes in information acquisition efficiency of a radar system,
providing guidance for system designers.
