From 8th to 10th of May 2013, A. Martini and N. Viltard participated in the 1st International CHUVA meeting in Sao Paolo, Brazil. The meeting was meant to discuss the first results from this series of field campaigns taking place in various regions of Brazil. The main purpose of CHUVA is to characterize the wide variety of the Brazilian climates and is thus an excellent test bed for rain validation. The main instrument of interest here is an polarimetric X-band radar that can be used for both product validation (rain) and algorithm validation (microphysics using Particles IDentification). Two presentations were given by the Megha-Tropiques representatives, one on product validation (Viltard et al) and one on algorithm validation (Martini et al.).