The vivax metrotech system for mapping underground assets like pipework and cable runs with a relatively high accuracy.
The equipment that has inspired this idea is the VIVAX METROTECH vSCAN range which can be viewed here. https://www.vivax-metrotech.com/
Like many utility detectors, It locates wires and buried metalic objects but what is so great about the direction of this product range is that it can combine with locating a sewer Inspection camera head which brings the ability to reality capture, with photogrammetry, inside of pipework or cable runs. Not the best result as it is only in one direction but there is nothing stopping this being developed into fore and aft cameras.
To do this, you send the vCamMX camera up the pipe or chamber which records all the image data while someone walks above the ground with the vLocCam2 Locator. This will provide the depth relative to the locator which records it geolocation.
It is also handy to be able to Geolocate all detected power lines and utility services like CATV, telephone and pipework over 50mm. I think thats a safe bet as the diameter of the smaller head is 18mm so might be able to be used in smaller bores to confirm the laying of a water pipe for instance but the manufacturer states 50mm.
There really is not much to say about this process as it is just amalgamating a current CCTV of sewers process with an upgraded utility detector with GPS but it is more the tool that makes it easy to process the data in an automated fashion.
Having said that, with the potential to 3D model the video, it can also aid non destructive computer based testing and defect detection of underground utility services.
The geolocation aspect of this also provides a way to satisfy much of the financial risk of PAS256 and the geographic linking between non-infrastructure assets.