Global Precipitation Measurement (GPM) mission's core satellite has been collecting precipitation data from space for more than a year. This paper reviews the performance of precipitation retrieval algorithm and evaluates the rainfall rates estimated with the Dual-frequency Precipitation Radar (DPR) onboard the GPM's core satellite. Differences between the rain estimates with TRMM's Precipitation Radar (PR) and those with GPM's DPR are examined.

The analysis (verification, diagnosis, control, etc.) of discrete event systems requires a correct model of the system and of its specifications. In this paper, we present a new modeling formalism for generating valid models of complex systems. The class of systems this applies to is one which consists of signals that take binary values. The technique presented here makes the task of modeling considerably less cumbersome and less error-prone and is user-friendly. Another advantage of using this modeling formalism is that the size of the system model is polynomial in the number of signals, whereas the number of states in the automata models is exponential in the number of signals. We present automated techniques for deriving an automaton-based model from the model in the proposed formalism. We illustrate the modeling formalism using examples drawn from manufacturing systems and process control.