This ancillary ICESat-2 data set contains the linear impulse response in units of time-of-flight (TOF), which was measured over the Salar de Uyuni using ATL02 photon data. The linear impulse response describes the observed shape of the laser pulse after it returns from a flat surface through the ATLAS instrument. The data can be used to model (sub-)surface scattering or remove instrument effects such as after-pulses from surface return data.