The Pulse Extension Loss of a Synthetic Aperture Radar Operating in the f-STEC Imaging Mode

The frequency-Scan for Time-of-Echo Compression (f-STEC) imaging mode considered in this paper utilizes the available bandwidth of a synthetic aperture radar (SAR) instrument to form a narrow frequency-scanning transmit antenna beam illuminating the imaged swath from far to near range. In this paper, a mathematical model for the antenna radiation pattern is developed taking the true time delays and complex beamforming coefficients into account and analyzed with respect to the effect on the frequency scanning properties. Further, a model for the radar return echo spectrum is presented taking the range compression filter into account. Deriving expressions for the signal and noise weighting factors give new insights into the Pulse Extension Loss (PEL) of f-STEC SAR