We have investigated two energetic particle events (28 keV--145 keV) upstream of the earth's bow shock with two identical experiments of the Max-Planck-Institut/University of Maryland on ISSE-1 and ISSE-3. Close to the bow shock the particle distribution is more or less isotropic and indicates strong scattering of the particles in the upstream wave field. At ISSE-3 the particles move essentially scatter-free from the general bow shock direction. The temporal evolution of the particle bursts is discussed in terms of the interplanetary magnetic field topology and the scattering conditions.