Charged particle data taken by the S3-3 satellite, reported by Mizera and Fennell (1977), are presented as contours of the velocity distribution function on a velocity-space diagram. This report focuses on the analytical technique used to interpret the particle data. Details of features exhibited by the electron and ion data in the velocity-space representations are discussed in terms of a simple electrostatic acceleration model. The observed particle populations are separated in velocity-space by recognizable demarcations calculated from the conservation laws in accordance with Liouville's theorem.