  NEOs come close to the Earth's orbit so that any dust ejected from them,
might be seen as a meteor shower. Orbits evolve rapidly, so that a similarity
of orbits at one given time is not suffcient to prove a relationship, orbital
evolution over a long time interval also has to be similar. Sporadic meteoroids
can not be associated with a single parent body, they can only be classified as
cometary or asteroidal. However, by considering one parameter criteria, many
sporadics are not classified properly therefore two parameter approach was
proposed.
