IMERG降水產(chǎn)品主要來(lái)源于GMI和DPR。GSMap產(chǎn)品由JAXA 開發(fā)的一款高時(shí)空分辨率衛(wèi)星降水產(chǎn)品。GSMap算法中，紅外數(shù)據(jù)和被動(dòng)微波數(shù)據(jù)的結(jié)合將高分辨率和高精度同時(shí)實(shí)現(xiàn)，其主要產(chǎn)品為GSMap_MVK和GSMap_Gauge。GSMap_Gauge產(chǎn)品是在GSMap_MVK基礎(chǔ)上，引入地面數(shù)據(jù)對(duì)其進(jìn)行改進(jìn)，一定程度上提高了GSMap_Gauge產(chǎn)品的準(zhǔn)確度及產(chǎn)品質(zhì)量。
TMI/PR combined instrument (TCI)
TRMM Microwave Radiometer (TMI)
precipitation radar (PR)
TRMM Multi-satellite Precipitation Analysis (TMPA)
the real-time TMPA (TMPA-RT)
the Integrated MultisatellitE Retrievals for GPM (IMERG).
The Version 7 TRMM product 3B42 is being computed with the TMPA after real time, and
constitutes the research-grade archive of TMPA estimates. Note that the version numbering for
the TMPA-RT and official TRMM products are not necessarily related, although both are currently numbered 7. The post-real time computation allows several improvements in 3B42 compared to 3B42RT:
- Data are processed starting with the first full month of TRMM data, which begins 1 January 1998.
- The IR calibration period is the calendar month in which the observation time falls, rather
than a trailing 30-day accumulation. - The TRMM Combined Instrument product (2B31) is used as the calibrating standard monthto-
month, which should give better estimates than the climatological calibration used in the RT. - For each grid box, the individual 3B42 3-hourly precipitation values are scaled to sum to a
combination of monthly 3B42 and gauge analysis, which is TRMM product 3B43.
3B42, ”TRMM and Other Sensors - 3-Hourly”, provides precipitation estimates in the
TRMM regions that have the mean of the ”TRMM Combined Instrument” precipita-
tion estimate and the dense sampling of high-quality microwave data with fill-in using
microwave-calibrated infrared estimates. The 3-hourly satellite estimates are then rescaled
to the monthly precipitation gauge data. The granule size is 3 hours. The following sec-
tions describe the structure and contents of the format.
Dimension definitions:
nlat 400 Number of 0.25o grid intervals of latitude from 50o N to 50o S.
nlon 1440 Number of 0.25o grid intervals of longitude from 180o W to 180o E.
