Enhanced imaging for through-the-wall radar with noise power spectrum estimation

Due to the attenuation effects of walls, the signal to noise ratio (SNR) for targets indoor is unavoidably decreased, which seriously influences the quality of through-the-wall imaging (TWI) results. To suppress the deterioration of noise and clutters yield by walls, an adaptive noise power spectrum estimation method is put forward in this paper to enhance the performance of TWI. Through a combination of a pre-treatment on the received signal and a replacement of the short-time power spectrum with the Frequency-Doppler spectrum, the minimum statistic based noise estimation method can be effectively performed in TWI. A threshold based on the method is chosen then to suppress the interference of noise. Experiment on practical TWI radar echo data validates the proposed method.