Parameterising the lateral distribution function for the SD-750 array of Auger including small signals

Implementation of triggers sensitive to smaller signals in the surface detector array (SD) of the Pierre Auger Observatory requires changes to the signal likelihood formalism used in the reconstruction of the lateral distribution function (LDF) and the energy of events. In this contribution, we discuss the choice of the LDF shape and changes in the likelihood minimisation for events recorded by the array with 750 m detector spacing (SD-750) of the Observatory. We present a new approach for the SD reconstruction, which will enable us to retune the LDF parameterisation and derive an updated spectrum for the energy range of cosmic rays between 1017.5 to 1018.5 eV.