Dual-frequency radars offer the benefit of reduced complexity, fast computation time, and real-time target tracking in
through-the-wall and urban sensing applications. Compared to single-frequency (Doppler) radar, the use of an additional
frequency increases the maximum unambiguous range of dual-frequency radars to acceptable values for indoor target
range estimation. Conventional dual-frequency technique uses phase comparison of the transmitted and received
continuous-wave signals to provide an estimate of the target range. The case of multiple moving targets is handled by
separating the different Doppler signatures prior to phase estimation. However, the dual-frequency approach for range
estimation can be compromised due to the presence of noise and multipath. In this paper, we investigate a sparsity-based
ranging approach as an alternative to the phase difference based technique for dual-frequency radar measurements.
Supporting results based on computer simulations are provided that illustrate the advantages of the sparsity-based
ranging technique over the conventional method.