why and how.
Why. Better distance measurement --> better values for anything that changes with distance. So tighter distance measurement (and presumably tighter range rate measurement) means having to carry less reserves for spacecraft going there. Obviously this would count for more if going to Saturn and Jupiter but that's not going to happen anytime soon.
How. The article points out they can use COTS lasers for this. It's the receivers that have to work hard. I'll take a wake and filter spec will be very tight to ignore most ambient light and they will use some kind of lockin detection to.
There's lots of subtle problems here. Constant offsets can be cancelled out but things like the Earths atmosphere are constantly changing (the biggest correction in GPS is for pulse delay through the ionosphere. The civilian code uses a model, the military system uses 2 frequencies to give something like 10x the accuracy).
Thumbs up for this. I suspect this will enable a whole lot of stuff to be improved.
Pity about the shark though....