The files contain the first version of the integrated water vapor (IWV) estimates obtained by use GPS (Global Positioning System) data collected during GPM-CHUVA experiment. There is a directory for each GPS stations belonging to campaign. These directories and files are denominated with 4 letters to indicate the station name. The names, coordinates and periods available of each GPS station are: DEFO: GPM-CHUVA-FORTALEZA Defesa Civil-CE Latitude: -3.727971 Longitude: -38.502194 Geometric Altitude: 10.4622 m Begin: 093 (03/04/2011) 00:00 End: 121 (01/05/2011) 23:55 Meteorological station used: - Anemometric Tower Chuva experiment. CEEU: GPM-CHUVA-FORTALEZA Euzébio-CE Latitude: -3.87754880 Longitude: -38.42554058 Geometric Altitude: 21.75 m Begin: 093 (03/04/2011) 00:00 End: 117 (27/04/2011) 23:55 Meteorological station used: - without meteorological station available. The data are presented in the following columns: 1. Date (YYYMMDDHHMI) (GMT) 2. Simple second Julian of the year - (GMT) 3. Integrated Water Vapor (IWV) - [kg/m˛] PS. Simple Second Julian is equal to number of second of the year in the required date. For instance a measurement done at 15:30:18 GMT at Marc 2nd, 2010 has Simple Second Julian equal to 5239818. Supplementary information about this version, contact: - Luiz Fernando Sapucci (luiz.sapucci@cptec.inpe.br);