Level 2G through level 4 products are considered gridded products. Gridded data are defined in a global non-overlapping grid. Globally, there are 460 tiles, of which 317 contain land pixels. Each tile has fixed Earth-locations covering an area of approximately 1200 x 1200 km (10° x 10° at the equator). All V003 MODIS Land tile products are defined in the equal area Integerized Sinusoidal projection (Rossow and Garder, 1984). All V004+ MODIS Land tile products are defined in the equal area Sinusoidal projection (Snyder, J.P. 1987). The tile vertical and horizontal coordinates are reflected in the product file name such as: MOD09GHK.A2004150.h13v05.004.2004152161345.hdf
reference
http://modis-250m.nascom.nasa.gov/developers/grids.html