Divine (1993) developed a mathematical model to use measurements of interplanetary dust to determine the orbital distributions of particles in interplanetary space. The power of the model is that it uses the fact that the dust particles are in Keplerian orbits to correct for the observation biases based on spatial density and velocity efifects of the orbits. In order to do this, he creates families of dust orbits; within each of which the particles have mathematically separable distributions of mass, periapsis, eccentricity, and inclination. He then uses a trial-and-error method to vary these distributions until an adequate fit is made to the data. Each of his distributions is loosely based on populations of interplanetary dust that are believed to be present in the Solar System.