Effect Of Photoacoustic Radar Chirp Parameters On Profilometric Information

Continuous wave photoacoustics has been under investigation for more than a decade. Matched-filtering and pulse compression techniques, which use a chirp waveform as input light source, have been implemented into this imaging modality to improve signal to noise ratio (SNR) and resolution. However, the chirp parameters’ effects on SNR are still not clear. The theory behind chirp parameters’ effects on SNR is discussed in this paper. It is found that in order to get a higher SNR, chirp duration T should be maximized, chirp center frequency 0 f should be controlled to make the chirp spectrum overlap with absorber spectrum, and chirp bandwidth  should be smaller or equal to the absorber bandwidth.