Unless someone has been through and opened them very recently I'd suggest one run to locate them, check not under pile of rubbish etc. and most importantly the lid is not seized! Make sure you exclude seized lid in your pricing. Second trip to do the actual surveying in production mode.
I just set in on a demo last week. The guys had came and did a scan around the company building office and had several manholes. They scanned and caught the tops of them all. Then they used some tripod inverted and dropped the scanner down and scanned one manhole was pushing 20 foot so a couple scans had to be done as it was lowered down. So they could register to the main cloud above ground. They had ran a good traverse around the site to tie the scanner to where they also had some building corners and top of manhole elevations and the inverts already done. Even the 20’ deep manhole came out very nice. One pipe was obstructed at the bottom and was easy enough to get the diameter of the pipe side ways then pick the top of pipe and based on size to compute the invert. I was amazed at how well everything worked with many independent checks.
