Outdoor LiDAR Boundary Mapping

I need a concise boundary-definition plan that lets me track human movement in a small outdoor space—think a plaza or pocket-park. You may choose either laser range-finders or LiDAR sensors; I’m flexible as long as the final solution reliably flags when a person enters or exits the defined perimeter... (Budget: ₹600 - ₹1500 INR, Jobs: 3D Scanning, 3D Visualization, Data Processing, Linux, Machine Learning (ML), Python, Robotics, Software Architecture)