Carrying both a dual frequency radar instrument and a passive microwave radiometer, the Core Spacecraft will serve as a calibration standard for the other members of the GPM spacecraft constellation.

The Core Spacecraft will be developed in-house at NASA Goddard Space Flight Center.

A scientific spacecraft carries numerous instruments designed to measure specific phenomena. Scientists must control, very precisely, where each instrument on the spacecraft is pointing, so that data is collected from the intended targets. Not only do the instruments have to be moved from target to target, they must be held steady on a target long enough, as the spacecraft moves through space, to collect the needed data.

GPM Instruments

GPM will be pointing toward Earth to measure precipitation. It will be vital to control the attitude (or physical orientation) of the Core Spacecraft accurately, so that we can map exactly where the resulting data originates on Earth. The Core observatory is uniquely instrumented with a conically-scanning radiometer and a cross-track scanning radar: :

+ GPM Microwave Imager (GMI)
+ Dual-frequency Precipitation Radar (DPR)

The well calibrated GPM Microwave Imager (GMI) measurements and the well characterized scene obtained from the Dual-frequency Precipitation Radar (DPR) will combine to provide an excellent reference against which to calibrate other microwave radiometers in the GPM constellation when overlapping measurements of same Earth scene are made. The DPR, will have the capability to make detailed, three-dimensional measurements of cloud structure, rainfall, and rain rates. These detailed measurements will provide further understanding of the microwave radiometric measurements made by the GMI.

Document Library

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that relate to the GPM Instruments