I just got off work and was fixing to go up a overpass I got a very brief Ka alert of 1. As i came up over the overpass a DOT DPS Tahoe lit me up with a KA9 for just a millisecond not even half a second at 200ft while moving. I'm guessing he lit up the car in front of me and I got a brief scatter before going up the overpass. I was doing 80 in a 65 and maybe had 2 seconds to react to the encounter. There was no traffic on the other side. The person in the car ahead did not have a RD cause i passed them later to scope. Be careful out there people. I was in FILTER mode. I believe FILTER 2 would have been to late.