A method for providing process tool correctables, comprising: performing a first measurement on a wafer of a first lot of wafers via an omniscient sampling process, wherein the omniscient sampling process includes measuring one or more parameter values at each measurement location of each field of the first wafer; calculating a first set of process tool correctables utilizing one or more results of the measurement performed via the omniscient sampling process, wherein the first wafer has N fields, wherein a first collection of process tool correctables is calculated for each field of the wafer of the first lot of wafers, and the first set of process tool correctables includes N collections of correctables; analyzing a process tool correctable signature across the wafer of the first lot of wafers by applying wavelet analysis to the first set of process tool correctables; determining a sub-sampling scheme utilizing the analyzed process tool correctable signature, wherein the sub-sampling scheme includes a set of field locations of the wafer and a set of measurement locations within each field of the wafer; performing a subsequent measurement on at least one wafer of a subsequent lot of wafers at each measurement location of each field of the sub-sampling scheme; calculating a second set of process tool correctables utilizing one or more results of the measurement performed utilizing the sub-sampling scheme, wherein a second collection of process tool correctables is calculated for each field of the sub-sampling scheme of the subsequent lot of wafers; and the second set of process tool correctables includes the collections of correctables of the fields of the sub-sampling scheme; and approximating a process tool correctable for each of a set of fields not included in the sub-sampling scheme of the at least one wafer of the subsequent lot utilizing one or more wavelet functions. performing a first measurement on a wafer of a first lot of wafers via an omniscient sampling process, wherein the omniscient sampling process includes measuring one or more parameter values at each measurement location of each field of the first wafer; calculating a first set of process tool correctables utilizing one or more results of the measurement performed via the omniscient sampling process, wherein the first wafer has N fields, wherein a first collection of process tool correctables is calculated for each field of the wafer of the first lot of wafers, and the first set of process tool correctables includes N collections of correctables; analyzing a process tool correctable signature across the wafer of the first lot of wafers by applying wavelet analysis to the first set of process tool correctables; determining a sub-sampling scheme utilizing the analyzed process tool correctable signature, wherein the sub-sampling scheme includes a set of field locations of the wafer and a set of measurement locations within each field of the wafer; performing a subsequent measurement on at least one wafer of a subsequent lot of wafers at each measurement location of each field of the sub-sampling scheme; calculating a second set of process tool correctables utilizing one or more results of the measurement performed utilizing the sub-sampling scheme, wherein a second collection of process tool correctables is calculated for each field of the sub-sampling scheme of the subsequent lot of wafers; and the second set of process tool correctables includes the collections of correctables of the fields of the sub-sampling scheme; and approximating a process tool correctable for each of a set of fields not included in the sub-sampling scheme of the at least one wafer of the subsequent lot utilizing one or more wavelet functions.