# IR Sensor to detect fast moving object

I have a somewhat specific need for a project I'm building: I am trying to create a sensor grid of 1.5m height by 2m wide that has to be able to detect objects, ~10cm in diameter, in potentially high light that are moving a maximum of 185kmh.

I want this grid to be as tight as possible because I want to then build x/y coordinates out of it through triangulation.

I'm looking for help on finding the correct type of sensors I should be using. I had considered some IR sensors, but experimenting with them I haven't found any that really give me the correct type of distance I'm looking for.

I have also considered ultrasonic sensors, but it looks like they are too slow to really handle anything moving as fast as I'm looking for.

Could I get some help and get pointed in the correct direction to find the type of sensors I'm looking for?

Generally speaking, intensity falls off with $$r^2$$, because a point source spreads light over an angular swath, so you can get some decent estimates with an IR sensor for most objects.