Long-period multiple suppression is a 2-step process: estimate multiples and then adaptively subtract. ISS and GP technologies estimate internal multiples using totally different methodologies. At well locations, GP synthetics validate ISS processing steps in the workflow. Well control is not necessary to estimate and/or suppress field seismic multiples … it validates the process.
With ISS estimation of internal multiples, the exact location of multiple generators is not as important as it is in the suppression of surface multiples.
Algorithm Validation – Multiple Estimation and Adaptive Subtraction 
Field Data – Multiple Estimation and Subtraction