Precipitation radiometers provide additional degrees of freedom for interpreting rain and snow in clouds through the use of multiple passive frequencies (9 for TRMM and 13 for GPM). Brightness temperatures at each frequency are a measure of everything in their field of view. These frequencies from the low (10 GHz) end to the high (183 GHz) end transition from being sensitive to liquid rain drops to being sensitive to the snow and ice particles.
Content which is not specifically affiliated with GPM or TRMM, but which is about the Precipitation Measurement Missions in general.
The combined use of coincident active and passive microwave sensor data provides complementary information about the macro and microphysical processes of precipitating clouds which can be used to reduce uncertainties in combined radar/radiometer retrieval algorithms. In simple terms, the combined algorithms use the radiometer signal as a constraint on the attenuation seen by the radar.
The unique function of precipitation radars is to provide the three-dimensional structure of rainfall, obtaining high quality rainfall estimates over ocean and land. Radar measurements are typically less sensitive to the surface and provide a nearly direct relationship between radar reflectivities and the physical characteristics of the rain and snow in a cloud. Because of the complexities of operating radar in space, limited channels (frequencies) are designed for the instruments.
Precipitation Processing System (PPS)
Precipitation data sets, referred to as "products", are available at a variety of levels which denote the amount of processing that data has been through. These range from the raw instrument data to precipitation model outputs which are mathematically derived using the raw data as an input. Below are the definitions for each level:
This page will allow you to log into the PMM Science Team Portal to collaborate with your fellow scientists. Some of the features we are planning include:
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- A wiki / forum for communication and sharing of ideas.
- A tool to schedule meetings with your fellow scientists.
- A tool for sharing documents and files.
Check back here for updates on the status of this tool.
- Access the restricted 2011 PMM Science Team Meeting files (PMM Science Team members only).
- Request a password to access the PMM Science Team Meeting files.
This meeting is for NASA PMM Science Team members and invitees.