GPM

Data Source Homepage
Description

The official website for NASA's Global Precipitation Measurement mission. 

IMERG Land-Sea Mask Binary

This file is the percent water surface coverage file used for the IMERG products in binary format. It is on a 0.1°x0.1° grid as REAL*4 (3600,1800). The orientation is the same as the IMERG data. The file displays percent water surface coverage with 100% = all water and 0% = all land.