R. Stauffer (NASA/GSFC), H. Vömel (NCAR), and J. Andrés Diaz (Universidad de Costa Rica) – Monthly and campaign-based launches of the Cryogenic Frostpoint Hygrometer since July 2005. Water vapor data provided up to ~28 km.  In addition to the CFH, the payload includes an ECC ozonesonde and a radiosonde, initially the Vaisala RS80 radiosonde.  The RS80 was superseded in April 2010 with the iMet-1-RSB radiosonde, and iMet-4-RSB radiosondes are used since July 2020.  Ancillary data include PTU, GPS altitude and winds together with ozone partial pressure and mixing ratio to ~30 km. The current launch site is located on the campus of the Universidad de Costa Rica in San Pedro.  Earlier sites at Juan Sanatamaria International Airport, Alajuela, the Universidad Nacional, Heredia, and the UCR Estacion Fabio Baudrit, are 19.2, 10.2 and 25.2 km, respectively, west of the UCR site.