When target sizes are comparable to the inherent resolution of a synthetic aperture radar (SAR) imaging system, images only produce representative points which can be used to detect and locate different targets but not distinguish any further between them. Using those representative points from the reconstructed image, we introduce a method that recovers a frequency spectrum from the same set of measurements. We show theoretically that this spectrum is related to the radar cross-section (RCS) of the target. For special cases when the proposed method is not able to distinctly image or recover frequency spectra from two different targets, we introduce modifications that resolve those issues. Using numerical simulations, we show that this spectrum provides valuable information allowing for differentiating targets that would otherwise be indistinguishable. Moreover, this method does not require any additional data than that already used for imaging. Including this spectral characterization opens opportunities to consider alternate strategies for managing resources for collecting and recovering target features contained in SAR measurements.