The article is kind of vague. What they seem to be doing is operating a ground penetrating radar under the vehicle so that underground details can be used as positional references. This is useful only if you have a map which includes that data. At best, this tells you where you are. It tells you nothing about what's ahead.

LIDAR units that return "first and last" returns are helpful in dealing with rain and fog. The first return (nearest thing seen) will be noisy in rain, but last (most distant thing in that direction) should be stable if it's from a solid object. "First and last" is used with aerial LIDAR surveying; "first" gives you the treetops, "last" gives you the ground.

Range gated imagers for seeing through fog and dust have been available for over a decade. These are active devices which allow filtering out anything that's outside a narrow image range gate. You can adjust the gate and get images layer by layer. This technology is used by the military and seems to be somewhat restricted.[1][2][3] In addition to fog, it can show what's behind a camouflage net, objects concealed by brush, and such.

The submillimeter radar people are slowly making progress, too.[4] Automotive radars are currently running at 77GHz, which is low resolution compared to LIDAR. The resolution gets better with frequency. There are now systems in the 300GHz range.

So the sensors needed are available now, in expensive forms, and can get cheaper.

[1] http://www.dvsmil.com/PDF/Imaging_Lidar_Seeing_Through_Cloud... [2] https://www.youtube.com/watch?v=hOTo-6jXOYo [3] http://www.sensorsinc.com/applications/military/laser-range-... [4] http://consortis.eu/