On the Possibility of Assessing the Geometric Characteristics of an Asteroid Using Radar Signatures

Abstract

The problem of backscattering of short radio pulses (broadband radio signals) from moving asteroid is considered. The Stratton-Chu diffraction integral is used, generalized to take into account the Doppler effect. A convex asteroid is approximated by a triaxial ellipsoid. A non-convex asteroid is modeled by two ellipsoidal bodies of different sizes connected to each other (model of the contact double asteroid 486958 Arrokoth). A series of radar portraits was constructed depending on the ratio between the lengths of the main semi-axes ellipsoid. A radar portrait of a non-convex asteroid is given for some non-coaxial with the line sighting the orientation of its parts. It is concluded that it is possible to restore the main geometric characteristics of the asteroid according to the radar portrait. It is noted that this approach allows us to find in real time the geometric characteristics of asteroids that interest us (simultaneous determination of the size of an object in the tangent plane and along the line of sight).