NHRA
They dont use a stop watch number one. Number two how do you think they get top speed number if they dont use radar or laser. Number three all vehicles have a radar signature and can be clocked accurately and precisely.
My radar gun will clock a BB. Im sure some cheapo models are not very useful. My gun gets the dust over 1000 feet away. The whiplash less than that.
10 years ago is an eternity in electronics.