Measuring Volumes and Boxes Indoors/No GPS

Hello,

I am trying to measure volumes for a project, but the mounds are inside of a warehouse/garage. Also trying to measure and capture a box under a road (Stormwater box). I know I won’t be able to get GPS in the warehouse or in the box. Has anyone here done any projects like this? If so, how did you approach it and what worked best to accurately capture the volumes and areas?

Thank you,

Nick