  We use the ultra-violet (UV) spectra in the range 230--300 nm from the
SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY
(SCIAMACHY) to retrieve the nitric oxide (NO) number densities from atmospheric
emissions in the gamma-bands in the mesosphere and lower thermosphere. Using
3-D ray tracing, a 2-D retrieval grid, and regularisation with respect to
altitude and latitude, we retrieve a whole semi-orbit simultaneously for the
altitude range from 60 to 160 km.
  We present details of the retrieval algorithm, first results, and initial
comparisons to data from the Michelson Interferometer for Passive Atmospheric
Sounding (MIPAS). Our results agree on average well with MIPAS data and are in
line with previously published measurements from other instruments. For the
time of available measurements in 2008--2011, we achieve a vertical resolution
of 5--10 km in the altitude range 70--140 km and a horizontal resolution of
about 9{\deg} from 60{\deg}S--60{\deg}N. With this we have independent
measurements of the NO densities in the mesosphere and lower thermosphere with
approximately global coverage. This data can be further used to validate
climate models or as input for them.
