2019_programme: IMPACT OF TEMPORAL DOPPLER ON CSAS IMAGERY



    • Session: 04. Towards Automatic Target Recognition. Detection, Classification and Modelling
      Organiser(s): Groen Johannes, Jans Wolfgang, Pailhas Yan, Myers Vincent
    • Lecture: IMPACT OF TEMPORAL DOPPLER ON CSAS IMAGERY [invited]
      Paper ID: 931
      Author(s): Herter Ulrich, Bonnett Blair, Schmaljohann Holger, Fickenscher Thomas
      Presenter: Fickenscher Thomas
      Presentation type: oral
      Abstract: Circular Synthetic Aperture Sonar (CSAS) coherently processes acoustic data acquired along a circular trajectory. One usual approximation applied is the stop-and-hop assumption (SHA) and, in particular, the assumption that the antennas are motionless during transmission and reception, i.e. the impact of temporal Doppler is ignored. However, in reality, for a particular ping half of the insonified area of a CSAS image centred around the point of rotation experiences pulse contraction while the other half experiences pulse dilatation. This phenomenon of temporal Doppler is incorporated into the simulation of raw data of point scatters for circular paths of a single transmitter multiple-receiver array. Results for images processed in time domain either with or without compensation of the temporal Doppler effect in the received signal are contrasted with each other. Comparative evaluation of the degradation is presented based on the shift and 6dB peak width of the point spread function (PSF) with the object locus, centre frequency, bandwidth, and pulse length as parameters. The errors caused by uncompensated temporal Doppler are compared with those caused by the SHA. Compensation of Doppler cell migration on CSAS data is presented and discussed.
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    • Corresponding author: Mr Herter Ulrich
      Affiliation: Helmut Schmidt University, Hamburg, Germany
      Country: Germany
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