  The Public European Southern Observatory Spectroscopic Survey of Transient
Objects (PESSTO) began as a public spectroscopic survey in April 2012. We
describe the data reduction strategy and data products which are publicly
available through the ESO archive as the Spectroscopic Survey Data Release 1
(SSDR1). PESSTO uses the New Technology Telescope with EFOSC2 and SOFI to
provide optical and NIR spectroscopy and imaging. We target supernovae and
optical transients brighter than 20.5mag for classification. Science targets
are then selected for follow-up based on the PESSTO science goal of extending
knowledge of the extremes of the supernova population. The EFOSC2 spectra cover
3345-9995A (at resolutions of 13-18 Angs) and SOFI spectra cover 0.935-2.53
micron (resolutions 23-33 Angs) along with JHK imaging. This data release
contains spectra from the first year (April 2012 - 2013), consisting of all 814
EFOSC2 spectra and 95 SOFI spectra (covering 298 distinct objects), in standard
ESO Phase 3 format. We estimate the accuracy of the absolute flux calibrations
for EFOSC2 to be typically 15%, and the relative flux calibration accuracy to
be about 5%. The PESSTO standard NIR reduction process does not yet produce
high accuracy absolute spectrophotometry but the SOFI JHK imaging will improve
this. Future data releases will focus on improving the automated flux
calibration of the data products.
