Two methods for estimating the pressure wavefield generated by a marin
e air-gun array are tested. Data have been acquired at a ministreamer
located below the source array. Effective source signatures for each a
ir gun are estimated. In the first method a nonlinear inversion algori
thm is used, where the forward modeling scheme is based upon a physica
l modeling of the air bubble generated by each air gun. In the second
method a linear inversion method is used, with the assumption that the
physics in the problem can be described by the acoustic wave equation
with explosive point sources as the driving term. From the estimated
effective source signatures, far-field signatures have been calculated
for both methods and compared with measured far-field signatures. The
error energy between the measured and estimated far-field signatures
was approximately 8 percent for both methods.