Observation nudging were not working!?

[wangxs]

I used radar to retrieve the data(u,v), and I had wrote the data(u,v) to little-r according to UCAR's help.
but it cannot make any change when I use observation nudging(&fdda).Can everyone help me? I am willing to your reply.
here is rsl.error.0000 OBS and namelist.input.

 

[Ming Chen]

It seems that this case is done successfully.

 

[wangxs]

but the V and U have nothing change when I use NCL to get some pictures. why？

 

[Ming Chen]

Can you extract U and V from the datafile before and after the nudging, then compare them? Note that the changes after nudging usually are not that big. NCL plots may not demonstrate obvious changes, even if the values are changed.