The Monthly Global Joint Product contains roughly 800 statistical datasets derived from Level-2 MODIS Atmosphere parameters that are summarized over a monthly period. It should be noted that the content of this product is identical to the Eight-Day Global Joint Product, except for the time period covered. The ESDT names are MOD08_M3 (Terra) and MYD08_M3 (Aqua).
L3 Monthly (08_M3) File Specification
(Common Data Language (CDL) Format)
The link below allows one to download and view the complete Common Data Language (CDL) file specification. This file spec gives a complete description of the MODIS Atmosphere Monthly (08_M3) HDF product file, including all the Scientific Data Sets and their local attributes.
L3 Monthly (08_M3) C6.1 File Spec (2.1 MB)
Monthly Product (08_M3) File Format Basics
Equal Angle Grid
L3 Multiday (8-Day & Monthly) Algorithm
There are a number of general L3 Multiday algorithm characteristics:
a) Only the L3 Daily files are used as input. (Greatly improves algorithm efficiency.)
b) L3 Daily and Multiday HDF files use an identical grid, SDS dimensions, and histogram bin definitions. (This is an algorithm requirement.)
c) There is no “valid range” check, only “Fill_Value” grid cells are universally excluded.