Could radar really detect the trajectory of basically a slightly large bullet? Thing is if you could fit it into a truck you’ve got potentially miles or more from around the target to choose from. I guess microphones could triangulate the origin of the boom but you get to choose the less likely area to have them. Also maybe you could design a boomless “flinger”. Like this maybe - https://www.youtube.com/watch?v=JAczd3mt3X0