A meteoroid in orbit around the Sun has a heliocentric velocity in the vicinity of Earth of about 42.1 km/s. So if a meteoroid has a heliocentric velocity exceeding that, it will have an open (hyperbolic) orbit and would not have originated in the solar system. As a meteoroid encounters Earth's atmosphere it encounters atmospheric atoms and molecules, generating heat that causes atoms to boil off and collide with those in the atmosphere. This produces ionized particles which surround the meteoroid with a glowing envelope leaving a column of plasma. The meteoroid is now seen as a meteor.
Meteor velocities measured by radar and optical means have indicated the detection of many hyperbolic meteoroid orbits (heliocentric velocities exceeding 42.1 km/s), but velocity measurement errors which occur in the 10% range have cast doubt on their interstellar meteoroid status. However, it's clear that the solar system must be embedded in dusts and gasses originating from nearby star systems, so the existence of hyperbolic meteoroids should not be in doubt.
What is the technical difficulty in obtaining sufficiently accurate velocity measurements to prove or disprove the existence of interstellar meteors?