%0 Journal Article %A Laws, Robert %A Landrø, Martin %A Amundsen, Lasse %T An experimental comparison of three direct methods of marine source signature estimation %D 1998 %J Geophysical Prospecting, %V 46 %N 4 %P 353-389 %@ 1365-2478 %R https://doi.org/10.1046/j.1365-2478.1998.980334.x %I European Association of Geoscientists & Engineers, %X Three methods for estimation of the pressure wavefield generated by a marine airgun array are tested experimentally and compared. In the trial a variety of radiation angles and array configurations were used and some large synchronization errors were deliberately introduced. The source was equipped with near‐field hydrophones and a subsource ministreamer. A tethered far‐field hydrophone was used so that the three estimated far‐field signatures could be compared with an independent measurement. The knowledge of the source signature is important for on‐board source array QC, deconvolution, multiple attenuation, stratigraphic trap prediction, modelling and inversion, AVO analysis and reservoir monitoring. The methods perform very well and give estimates whose frequency‐domain spectra match the measured spectra to within a few dB and within a few tens of degrees of phase over the tested bandwidth of 3.5–110 Hz. The time‐domain error‐energy is typically only a few per cent of the signal energy for radiation angles within about 30° of the vertical. The third method proved to be sensitive to an experimental shortcoming leading to overloading of the ministreamer and meaningful comparison was not possible for some test configurations. %U https://www.earthdoc.org/content/journals/10.1046/j.1365-2478.1998.980334.x