GAOFEN -4 and CBERS 4 satellite images

Hi All
We are working on a project where we need to do analysis of satellite images with TIR bands. Currently we are looking in Landsat and Modis. But we need to get images from other sources, namely
a) Gaofen – 4 OR GF – 4 or later
b) Aster
d) HJ 1

Can someone please let us know from where I can directly download such images, the parent source. I am not able to find them as readily as I can for Landsat or Modis.

Looking them up, I do not believe their images are publicly available. Gaofen is described as a “spy satellite” in some places…