GPR Survey in Mehrauli, South Delhi — Utility Detection & Mapping

Mehrauli presents Delhi quartzite close to the surface, with archaeological deposit through the settlement ground, and that is what sets the depth we can honestly report: typically 1.5 to 2.5 metres above rock, shallower still in parts of the old settlement. Coverage rate is secondary here; what matters is the depth the ground permits. For works below that ceiling we scope electromagnetic locating or trial holes alongside the radar rather than overselling one method.

How the survey is run here

How closely we run the lines in Mehrauli follows the material, not a fixed template. Where the ground itself reflects, we add perpendicular passes to separate the material from real utilities. Rather than one calibration per job, we take one per ground condition encountered. Owned systems and our own operators, which removes the usual reason a survey start slips.

What you receive

Drawings issued as layered DWG in your own standard, with per-feature depth, method and reliability held as attributes rather than as notes. Where a GIS exists we deliver into it as SHP or KML, and a PDF issue accompanies every package. A signed report recording coverage, achievable depth by section, refused access and the limits of what the method resolved. On Mehrauli work the report also records the authorities involved — the archaeological authority, South Delhi corporation zone, PWD, DDA on park land, forest authorities on ridge land — because the deliverable has to satisfy whichever of them receives it. Raw traces are stored indefinitely, which is what allows a finding to be defended rather than merely asserted.

Beyond the basics

Do you report archaeological findings? Yes, separately. A thousand years of settlement has left deposit well beyond the marked monument boundaries, and it registers clearly on radar.

Why is a bore priced differently here? Because rock sits close to the surface. A crossing priced on the standard Delhi alluvium assumption is revised at the first pilot.

Do you work in the farmhouse belt? Regularly. Large private plots carry servicing laid by individual owners with no consolidated record anywhere.

What does the Mehrauli report contain? Three schedules rather than one: utility positions, the rock profile along the alignment, and any archaeological anomalies.

Is the survey affected by traffic or vibration? Not materially. Radar is not a seismic method, so passing traffic does not corrupt the record, though it does constrain where and when a crew can stand.

Terms used on this page

Archaeological anomaly — a buried wall, floor or foundation detected alongside services and reported in its own category. Rock head — the level at which competent quartzite begins, below which radar cannot usefully see. Settlement deposit — accumulated material from centuries of continuous habitation, which reads as layered anomalies on radar. Unattributed find — a detected service that no asset owner claims, reported as such rather than assigned on plausibility. Quality level — a SUE grading describing how utility information was obtained, from records only through to physical verification.