IMERG Early Run
Near real-time low-latency gridded global multi-satellite precipitation estimates
Description
This algorithm is intended to intercalibrate, merge, and interpolate “all” satellite microwave precipitation estimates, together with microwave-calibrated infrared (IR) satellite estimates, precipitation gauge analyses, and potentially other precipitation estimators at fine time and space scales for the TRMM and GPM eras over the entire globe. The system is run several times for each observation time, first giving a quick estimate (IMERG Early Run) and successively providing better estimates as more data arrive (IMERG Late Run). The final step uses monthly gauge data to create research-level products (IMERG Final Run).
The main difference between the IMERG Early and Late Run is that Early only has forward propagation (which basically amounts to extrapolation) due to the short latency, while the Late has both forward and backward propagation (allowing interpolation).
Notes:
- The PPS has completed reprocessing GPM IMERG data for IMERG V07B. The IMERG dataset now includes TRMM-era data going back to January 1998.
- As of IMERG V7B, full coverage is provided at all latitudes, except for a few boxes very near the poles,
Processing Level
3
Current Algorithm Version
V07B
Dates Covered
Jan. 1998 - Present
Minimum Latency
4 hours
Spatial Resolution
10km / 0.1 Degree