Estudio de las observaciones de tropopausa sobre el cono sur de Sudamérica mediante GPS a bordo de los satélites SAC-C y CHAMP

validation of radio occultation technique by global positioning system (gps), carried out on board the sac-c and champ satellites, is analyzed over three stations of chile and four for argentine, as a reference for south america during 2001-2003. the discussion is based on the statistical comparison of the data of gps with data from nearby radiosonde measurements. though the occultation concept for obtaining profiles of atmospheric parameters, data derived from gps, were used to calculate tropopause temperature, pressure and altitude. the comparison of the two data sets shows that gps sounding are in good agreement with expected results, especially at [0,10] km of altitude. extratropical tropopause (80°s -60°) height values derived from gps shows levels around 9 - 15.3 km , while temperatures data provides a range of (204 - 222) k. water vapour pressure estimation provide a trend with a significant change of behaviour between upper troposphere and lower stratosphere, where the parameter decrease while altitude increase, especially near the tropopause region.