Meteoroid stream identification: a new approach - I. Theory

We introduce a new approach to meteoroid stream identification, based on a distance function involving four geocentric quantities that are directly li nked to observations; the new distance function is thus defined in a space that has as many dimensions as the number of independently measured physica l quantities, at variance from the conventional orbital similarity criterio n of Southworth & Hawkins. Two of the new variables turn out to be near-inv ariant with respect to the principal secular perturbation affecting meteoro id orbits, the one associated with the cycle of omega.