We have used data from the European Incoherent Scatter (EISCAT) facility to determine the characteristics of particle precipitation before and within auroral breakups and westward traveling surges. The EISCAT data of electron density versus altitude were transformed into energy spectra of the precipitating electrons [Kikrwood and Osepian, 1995>. We have used other ground-based data such as auroral images and magnetic recordings to put the EISCAT observations into the context of the substorm development. In particular, we tried to determine the exact location of EISCAT with respect to the initial auroral forms of an onset. Characteristic differences are found in the deduced energy spectra of the precipitating electrons for the onset and the WTS events. Both the WTS and onset spectra showed a tendency of superposed spectral peaks at 10 keV and 20--30 keV respectively, which could be related to a near Earth acceleration mechanism. The conductance ratio in the onset events was twice as high as in the WTS events and also the measured particle fluxes were higher. We will discuss the implementations of our results for our understanding of particle acceleration mechanisms during the very onset of the substorm. ¿ American Geophysical Union 1996