Jens Bosenberg Max-Planck-Institut fur Meteorologie, Bundesstr. 55,
D-20146 Hamburg, Germany TESLAS, which stands for Tropospheric
Environmental Studies by Laser Sounding, was formed in November 1987 as
a subproject of EUROTRAC to enhance the measurement capabilities for
vertical profiling of ozone in the troposphere by means of laser remote
sensing. For studies of several atmospheric processes related to the
formation and redistribution of photo-oxidants there was a clear need
for measuring extended time series with appropriate vertical and
temporal resolution. These could not be obtained by conventional in situ
techniques, at least not with affordable effort, so remote sensing
appeared to be the best way to obtain the required information. At the
beginning of the subproject, some Differential Absorption Lidar (DIAL)
systems for measuring the vertical distribution of ozone already
existed, but their use was restricted to very few laboratories and very
few measurement campaigns, since the instruments were highly complex,
rather unreliable, and required extensive efforts for maintenance and
operation by skilled scientists. In addition, the accuracy of these
measurements under a variety of meteorological conditions was not really
well established. The main tasks within TESLAS therefore were to develop
fully the DIAL-methodology for remote sensing of tropospheric ozone, and
to develop instruments which are accurate, reliable, easy to operate,
and suitable for field deployment or airborne operation.