Start here to understand the GRaND archive: Dawn GRaND Archive Description
Custom IDL software is available for ease of access and processing of raw GRaND data for scientific analyses, at the NASA GitHub Dawn GRaND Toolbox . However, the IDL software is not necessary to access and use the GRaND data, as all information to do so is available in the PDS4 labels.
GRaND is a nuclear spectrometer which measures the spectrum of planetary gamma rays and neutrons which originate from galactic cosmic ray interactions and the decay of radio elements within the regolith of the target body. This instrument uses a total of 21 sensors with a very wide field of view to measure the elemental composition of both Vesta and Ceres.