Introduction The idea of GPS Meteorology is to use tropospheric delay of GNSS microwave for meteorology which is considered as noise in positioning. There are similar approaches in GPS (GNSS) environment monitoring. Multipath error is induced as synthesized GNSS waves between direct signal and reflected signals. Because reflected point of microwave from surface changes with snow depth and soil moisture, multipath can be used to monitor such information. GPS microwave attenuates when it passes through vegetation. Signal to noise (S/N) ratio observed in GPS(GNSS) is also used to monitor leaves of trees and vegetable.