An Allpass Chirp for Constant Signal-to-Noise Ratio Impulse Response Measurement

A method for designing an allpass chirp for impulse response measurement that ensures a constant signal-to-noise ratio (SNR) in the measurement is presented. By using the background noise and measurement system's frequency responses, a measurement signal can be designed by specifying the group delay trajectory. This signal will have a small crest factor and will be optimally short such that the measured impulse response will have a desired and constant SNR.