The source designature process consists of two components: zero phasing and de-bubbling of the ghost-free far-field signature.
The process is known in PGS software environment as BOSS+ (Bandwidth Optimized Signature Solution).
The near-field source signature can be derived using both PGS Nucleus®+ modeling software and the near-field hydrophones. These hydrophones record the signal emitted close to each gun station. Using both Nucleus+ and the near-field hydrophones provides a hybrid signature. A hybrid signature can be generated for each shot or sail line, or one for the entire survey.
The calculated hybrid far-field signature includes the instrument response.
The desired output processing wavelet is derived from a zero phase equivalent of the modeled instrument response which is tapered to match the natural decay of the far-field's amplitude spectrum. The desired output wavelet is designed to preserve the total energy of the far-field signature. The designature operator is obtained by matching the raw far-field signature to the desired zero-phase wavelet.
The key benefit of the BOSS+ flow is the preservation of the full bandwidth as no predictive deconvolution is employed. PGS BOSS+ ensures that the low frequencies of the signal have been zero-phased appropriately.
The designature process is generally applied as a 1D filter but can also correct for variation in emergence angle through the application of a multi-dimensional designature operator.
The deghosted pressure wavefield before (left) and after (right) hybrid BOSS+ designature