>>2854433Not being a dick, but I'm not quite sure what you're trying to achieve here.
Accurately map your basement?
Surely all you need is a tape measure.
Why is this important? Wouldn't it be easier just to get the plans for your house?
If plans vs. construction are anything like where I live, tolerances are as follows. Surely this is accurate for any conceivable purpose?
Location on Site: Within 15mm of the plan.
Building Footprint/Wall Location: ±5mm for every 200mm of length (e.g., ±5mm on a 200mm wall).
Vertical Deviation (Out of Plumb): Around 15mm per two storeys (or 5mm per 2.4m height).
Surface Flatness: Different finishes have different rules (e.g., U3 trowelled floors: <3mm abrupt changes, <5mm gradual).