  Utilizing the all-sky imaging capabilities of the LWA1 radio telescope along
with a host of all-sky optical cameras, we have now observed 44 optical meteor
counterparts to radio afterglows. Combining these observations we have
determined the geographic positions of all 44 afterglows. Comparing the number
of radio detections as a function of altitude above sea level to the number of
expected bright meteors we find a strong altitudinal dependence characterized
by a cutoff below $\sim$ 90 km, below which no radio emission occurs, despite
the fact that many of the observed optical meteors penetrated well below this
altitude. This cutoff suggests that wave damping from electron collisions is an
important factor for the evolution of radio afterglows, which agrees with the
hypothesis that the emission is the result of electron plasma wave emission.
