Knowledge of radar scattering characteristics is very important to the development of radar detection technology on aircraft wake vortices. In this paper, the high range resolution (HRR) profile of the wake vortex is investigated. The HRR profile is observed to have a particular structure, from which the wingspan of the aircraft can be easily identified. This characteristic could be very useful to identify the wake vortex from the ambient air. At the same time, the Bragg scattering, whose characteristic and applicability are further explored, is used to explain the mechanism of such particular HRR profiles.