Estimating the frequency dependent behavior of marine sediment sound speeds using low frequency aircraft sound

For investigating the dispersion behavior of sediment sound speeds, broadband sound speed measurements are required. Sediment sound speed dispersion models predict the largest sound speed variations typically at low frequencies. Aircraft fly‐over noise acquired on receivers placed in sediment proved to be a promising approach towards broadband low‐frequency measurements. Since the magnitude of the Doppler‐shift depends on sound speed at the receiver position, the observed Doppler‐shift can be used to derive the sound speed. We propose a new approach using the entire time series instead of employing only the two observed frequencies at approaching and departing. It is based on a model for received signals, accounting for the Doppler‐shifted frequency. By maximizing the match between modeled and measured time series as a function of sound speed and frequency in a least‐squares framework, estimates of the frequency‐dependent sound speed are obtained. The method is applied to data acquired at receivers placed...