  Occultations of stars by asteroids have been observed since 1961, increasing
from a very small number to now over 500 annually. We have created and
regularly maintain a growing data-set of more than 5,000 observed asteroidal
occultations. The data-set includes: the raw observations; astrometry at the 1
mas level based on centre of mass or figure (not illumination); where possible
the asteroid's diameter to 5 km or better, and fits to shape models; the
separation and diameters of asteroidal satellites; and double star discoveries
with typical separations being in the tens of mas or less. The data-set is
published at NASA's Planetary Data System and is regularly updated. We provide
here an overview of the data-set, discuss the issues associated with
determining the astrometry and diameters, and give examples of what can be
derived from the data-set. We also compare the occultation diameters of
asteroids with the diameters measured by the satellites NEOWISE, AKARI AcuA,
and IRAS, and show that the best satellite-determined diameter is a combination
of the diameters from all three satellites.
