HDF file opening error in Grads

I am using TRMM satellite 3 hourly rainfall data for my research. This data is in .HDF formate while I am opening in grads it gives following error.
For reference I am attaching one sample file so you will be able to see the problem.
What to do?

ga-> sdfopen 3B42.980101.12.6.HDF
Scanning self-describing file: 3B42.980101.12.6.HDF
SDF file has no discernable X coordinate.

Is HDF formate is comfertable to use in fotran programming.
I mean isthis formate data can be manipulated with simple tools available in linux or there is somesoftwares which is must for handling HDF Data.


Indian Centre for Climate and Sociatal Impacts Research

3B42.980101.12.6.HDF (4.42 MB)