Is the TSI being used by the US National Weather service?
Yes, the US National Oceanic and Atmospheric Administration (NOAA), the parent agency of the National Weather Service, has TSI-440s at 5 SURFRAD sites. There is also a live TSI-880 system at the Albany, New York NWS office at http://tsi880.asrc.cestm.albany.edu Operational TSI systems are located all over the planet but many are behind firewalls due to agency security policies. The original TSI concept was developed in part by a partnership between USDA, NOAA and YES.