OFC & Telecom Duct Route Feasibility Survey with GPR

Rates and page checked: 23 October 2026

What is GPR scanning for OFC routing?

GPR scanning for OFC routing is a survey done before any duct is laid. It answers one practical question for the network planner: can the fibre go along this alignment without hitting what is already buried, and if not, where should it go instead?

Our crew runs ground penetrating radar along the proposed duct line and electromagnetic locators over any conductive services. The result is a picture of existing cables, pipes, ducts and chambers along the route, marked on the ground and written into a signed report.

This page covers the survey only. If you also need the duct laid, cable blown and the route built, that work is described on our OFC laying service page. Many clients order the two separately: survey first, then a laying contract based on what the survey found. For a step-by-step technical read, see our guide to GPR scanning for OFC routing.

What does a telecom duct route feasibility survey check?

A telecom duct route feasibility survey is not just a list of utilities. It tests whether the planned route can actually be built. On each stretch we look for:

• Parallel services – power cables, water mains, sewers, gas lines and other operators' ducts running alongside the planned duct, and how close they are.
• Crossings – every point where an existing service passes under or across the alignment, with its approximate depth.
• Congested strips – stretches where so many services share the verge or footpath that a new duct has no clear space.
• Chambers and manholes – visible and buried structures that the duct must avoid or connect to.
• Obstructions – culverts, buried foundations, old abandoned lines and unidentified objects, recorded as unidentified when no owner is evident.
• Ground limits – sections where soil or moisture reduced radar depth, so a deeper service could be present undetected.

From these findings the planner can confirm the route, shift it to the other side of the road, change the planned depth, or switch a section from trenching to a bore.

How is a fibre route scanned in the field?

The method is the same whether the route runs through a city or along a rural highway, though line spacing changes with congestion:

1. Route file check. We start from your KML or route drawing, the total length, the planned side of the road and any alternatives already under consideration.
2. Walkover. The crew notes visible chambers, poles, marker posts, valve covers and recent trench scars, which hint at what lies below.
3. Radar lines along the alignment. Continuous passes follow the planned duct line, with extra passes on an offset if the planner wants a fallback position.
4. Cross-lines. Short lines across the route at regular gaps, and at every junction, chamber and crossing, catch services that cut across the path.
5. EM locating. Conductive services such as live cables and metal pipes are traced and confirmed with an electromagnetic locator.
6. Ground marking. Detected services are painted or pegged on site with approximate depth.
7. Report. Findings, depth reached on each section, stretches we could not access and the reasons are written up and signed.

On open corridors with few obstructions, crews working day and night shifts have reached 100 km in a day, and our highest monthly output so far is 700 km in 30 days. Night working is quoted separately.

Which crossings decide whether a fibre route is feasible?

Long fibre routes are usually won or lost at a handful of crossings. These are the points we scan most closely:

• Railway lines – usually crossed by HDD, with strict rules on where pits can sit. We scan the bore path and both pit areas.
• National and state highways – carriageway crossings and junctions, where services from several owners converge.
• Canals, drains and nalas – where the duct must pass beneath a water body or culvert, and existing services may already use the same crossing.
• Bridge approaches – where ducts are often forced into a narrow strip beside the abutment.

For a crossing that will be bored, the scan gives the drilling team a clear path and depth band. Our HDD route survey page explains that work in more detail, and our own HDD rigs can drill the crossing after the survey if you want one contractor for both. Permissions to enter railway or highway land, and traffic arrangements, remain separate items arranged with the land owner.

How does an underground fiber optic network survey find existing ducts?

Existing telecom ducts are the hardest thing to find on most fibre routes, and the ones most likely to be hit. Many are HDPE pipes, which do not conduct electricity, so an EM locator cannot follow them unless a tracer wire or metallic cable is inside. Radar can still detect them, because the duct differs from the surrounding soil, but the signal depends on duct size, depth and ground moisture.

In an underground fiber optic network survey we therefore rely on radar for ducts and use EM wherever an armoured cable or tracer can be energised or picked up. Chambers and joint pits seen on the walkover help confirm a duct's path between them. Where the radar picture is weak, the report says so, and we can open a trial pit at a chosen point to confirm. Our article comparing the EM cable locator and GPR explains why both tools are needed.

What does the route survey deliver to the network planner?

The standard survey output is practical and site-focused:

• ground marks for every detected service along the alignment;
• a signed report listing each find, its approximate depth and the method that found it;
• a note of the radar depth achieved on each section;
• a list of stretches we could not scan, with the reason – parked vehicles, flooding, locked premises or permission limits.

If the work order asks for a depth profile, the L-section GPR survey adds the depth of detected services along the route at ₹32 a metre. CAD or GIS drawing sets can be prepared from the survey data on request; they are quoted separately and are not part of the metre rate.

How is an OFC route survey priced?

Pricing follows our standard rate card. A route survey costs ₹24 a metre (₹24,000 a kilometre), and the L-section version costs ₹32 a metre. The smallest order we bill is 4 km. For projects outside Delhi NCR, a ₹1,00,000 per-project minimum also applies; inside Delhi NCR, only the 4 km rule does. GST is extra.

The discount covers the whole order once it crosses a slab – 25% above 100 km, 40% above 500 km, 50% above 1,000 km. Mobilisation, night shifts, traffic arrangements and permissions, and CAD/GIS drawing sets are always charged separately. Full details are on the GPR survey price list.

When in the project should the route survey happen?

The survey is most useful after a route has been drawn on the map but before the laying contract is fixed. At that stage, a clash can still be solved by moving the line, changing the depth or adding a bore, without variation claims or idle crews. Surveying after laying has begun leaves only expensive options.

Operators and EPC contractors building telecom networks commonly order it at the feasibility or detailed-design stage, sometimes over several alternative routes. Our telecom operators page describes how survey work fits into wider network programmes. With 58 company-owned GPR systems and in-house crews mobilising from Faridabad, we can run long routes in sections so design can move forward as each section's findings are issued.