This data set contains visible-wavelength (0.435-0.925 micron) spectra for 1341
main-belt asteroids observed during the second phase of the Small Main-belt Asteroid
Spectroscopic Survey (SMASSII) between August 1993 and March 1999. The purpose of
the SMASSII survey was to provide a new basis for studying the compositional
diversity and structure of the asteroid belt. Based on experiences gained from the
earlier SMASS survey, SMASSII focused on producing an even larger, internally
consistent set of CCD spectra for small (D < 20 km) main-belt asteroids. The
observing strategies and procedures used during SMASSII roughly parallel those used
in the first survey (Xu et al. Icarus 115 1-35, 1995), though several minor changes
were made in instrumentation and in portions of the data reduction process.

This data set contains low-resolution, near-infrared (0.8 - 2.5 micron) spectra of asteroids obtained with SpeX at the NASA Infrared Telescope Facility (IRTF) on Mauna Kea. Since it was commissioned in June 2000, SpeX has been the premier instrument for producing high quality near-IR spectra of asteroids. These spectra have been used for both taxonomic studies of asteroids, and for more detailed mineralogical and compositional investigations. This data set archives the reduced, calibrated spectra that have been published in the peer-reviewed literature, and will be regularly updated as more data become publicly available.