With geeky HRM Maps from the Strike Eagle in mind, i was playing around a bit with the - at least from me- much neglected A/G Radar of the Jeff and did some small test setups.
As it turns out, some Vehicles seem not to have a Radar return.
Attached there are 2 Screenshots - The Setup and the best Picture i could get in DBS 2 - Zoomed in as much as possible.
Whilst 2 Command Centers, BMP3 and T80U give clear radar returns, a DSHK Pickup does not (okay, i can dig that. its small) nor does A Scud Launcher (thats the part i cant understand).
This sounds like the sort of thing you used to be able to look at in the lua files, but sure if that's still possible. Have you tried looking at the same targets in something else? I'm not so up on what has good A/G radars, but maybe the f-16 might be worth a try.
The JF-17 is a really under-represented model, I wish there was more single player content for it.