Tech guide — Buying a survey
How to Choose GPR Survey Company Quotes: 10 Checks
Ten questions that separate a capable GPR contractor from one that only owns a radar, with good answers and red flags.
Quick AnswerKnowing how to choose GPR survey company quotes comes down to ten checks. Look for owned equipment and crews, trained interpreters, radar plus locator, a site-specific method and on-site depth calibration. Add confidence grades with trial pits, survey-grade positioning, a sample deliverable, a safety and traffic plan, and a written per-metre price. Specific answers beat promises. For why two instruments matter, see more on EM Cable Locator vs GPR.
How do you choose a GPR survey company?
Ask ten practical questions about equipment, people, method, verification, deliverables, safety and price, and judge the answers by how specific they are. Ground penetrating radar, a geophysical tool that maps buried objects from reflected radio pulses, is now easy to buy. The skill to plan, collect, process and grade the data is not. A good firm names its antenna and depth calibration, and states what it cannot see on your site, while a weak one promises to "find everything".
The checks suit a single plot, a city road or a 500 km fibre route. They apply to us as much as to any other bidder you are considering.
Send every bidder the same short brief covering the site, the underground utilities you expect from existing records, the deepest one, the purpose of the drawing and your coordinate system. Ask for replies point by point against the ten checks, and visit the site first on anything longer than a few hundred metres.
Checks 1–3: who owns the equipment and who does the work?
Check 1, owned equipment, own crews: Ask how many GPR systems the firm owns and whether its own staff will be on site. Hired-in kit and sub-let crews break the link between planning and data collection, and they make dates harder to keep across several sites.
Check 2, trained operators and a named reviewer: Radar interpretation is a skill, so ask who processes the data and who checks it. PAS 128:2022 added guidance on practitioner training for this reason, and a named engineer signing the drawing is a good sign.
Check 3, radar and locator together: An electromagnetic locator finds conductive lines and tells you which cable is live, while radar finds plastic pipes, empty ducts and voids. A firm offering only one sells half a survey.
Checks 4–6: is the method right for your site?
Check 4, a method statement written for your ground: Antenna frequency, scan spacing and direction should follow from your target depth, soil and layout. Clay, saline ground and reinforced slabs all limit radar, and a frank contractor says where.
Check 5, a stated way of calibrating depth: Depth from radar depends on wave speed in the soil. Ask whether the crew calibrates on site against a hyperbola or a known-depth service, and how depth tolerance is reported. Our own approach is set out in more on GPR Depth Accuracy.
Check 6, confidence grading and trial pits: Every line should carry a quality level, and critical crossings should be offered for exposure by hand or vacuum excavation. That step helps reduce risks of accidental utility strikes and the service disruptions they cause. The framework is explained in SUE survey for site teams.
Checks 7–8: what will you receive?
Check 7, survey-grade positioning on your coordinate system: Marks should be fixed by DGPS or total station on the project coordinate system and height datum, not sketched from tape offsets. Ask for the coordinate list with the drawing, because accurate utility maps and reliable utility data both depend on it.
Check 8, a sample deliverable and evidence: Request a sample drawing and report, with a legend of quality levels, depth references, clearly shown gaps and radargram snapshots at doubtful points. To read those images, see GPR Radargram Library explained with real examples. Raw data on request is a further mark of confidence.
Checks 9–10: safety, permits and price
Check 9, safety system, permits and road plans: Ask for safety certification, a traffic method for live roads and the permit routine for plants and campuses. UK HSE guidance (HSG47) splits safe excavation into planning, locating services and safe digging, and a survey firm should cover the middle step without gaps.
Check 10, a transparent written quotation: The quote should give the rate per metre and drawing type, minimum order, distance discounts, GST, mobilisation, crew days and drawing delivery date. Vague lump sums make comparison impossible and invite disputes when the measured length changes.
The 10 checks at a glance
| # | Check | A good answer | A red flag |
|---|---|---|---|
| 1 | Equipment and crews | Company-owned systems, own staff on site | "We will arrange a machine" |
| 2 | Competence | Named processor and reviewer | Nobody owns the interpretation |
| 3 | Methods | GPR plus EM locator and sondes | One instrument only |
| 4 | Method statement | Antenna, spacing and limits for your site | Same plan for every job |
| 5 | Depth | On-site calibration, stated tolerance | Depth "guaranteed to the centimetre" |
| 6 | Confidence and pits | Quality level per line; pits offered | "We find 100% of services" |
| 7 | Positioning | DGPS or total station, your coordinate system | Hand sketch with tape offsets |
| 8 | Deliverables | Sample drawing, radargrams, raw data on request | No sample available |
| 9 | Safety | Certified system; traffic and permit plans | No plan for live roads |
| 10 | Price | Rate, minimum, discounts, GST, dates in writing | Lump sum with no basis |
For an open area instead of a route, also ask whether the firm will scan a dense grid; see: 3D GPR vs 2D GPR for what that changes.
Which warning signs should make you look elsewhere?
Promises of certainty, no sample work, no stated limits, and a price that cannot be broken down. Ask a direct question when:
- radar is claimed to see every service at any depth in any soil;
- depth is promised to the centimetre without a trial pit, or nobody can name the antenna and line spacing;
- the drawing shows no gaps, even where cars or water blocked scanning;
- the quotation is a single figure with no length, rate or delivery date.
How does Mezux Touch answer these checks?
Briefly: 58 company-owned GPR systems, our own crews with no sub-letting, combined radar and locator work, ISO 9001, 14001 and 45001 certification, and a published rate card. We have run utility survey work since 2003 across more than 1.5 lakh km of routes. Delhi NCR crews reach site the same day or within 1 working day. A colleague is based in every city on our list, so work outside NCR opens at once or by the following working day. Travel or mobilisation is priced only where it applies.
Standard GPR scanning costs ₹24 per metre and ₹32 per metre with an L-section, GST extra. Minimum order is ₹50,000 in Delhi NCR and ₹1,00,000 elsewhere in India. Lengths beyond 100 km earn 25% off the full order, beyond 500 km 40%, and beyond 1,000 km 50%. Put us through the same ten checks: talk to the survey desk and ask for a sample drawing with your quotation.
Sources
- American Society of Civil Engineers, “Newly updated ASCE 38-22 utility engineering standard and new companion standard ASCE 75-22 now available”, July 2022. www.asce.org
- BSI, PAS 128:2022 “Underground utility detection, verification and location. Specification” (training and qualification guidance). knowledge.bsigroup.com
- Health and Safety Executive (UK), HSG47 “Avoiding danger from underground services”, third edition, 2014. www.hse.gov.uk
Frequently asked questions
What should I ask a GPR survey company before hiring?
Ask what equipment they own and who will do and review the work. Then ask which methods they use, how they calibrate depth, what the drawing will show and how the price is built up.
Is the cheapest GPR quote a good idea?
Only if it covers the same length, methods, deliverables and verification as the others. Compare the per-metre rate and what is included, not only the total.
Should a GPR survey include trial pits?
For critical crossings, yes: radar gives detection, while a pit gives measured position and depth.
Can a GPR company guarantee finding all services?
No honest firm will, because radar and locators have limits in clay, salty ground and under metal, which a good report states.
What deliverables should a GPR survey include?
A coordinated CAD drawing, a point list, a short report with limits and confidence, and radargram images at doubtful points.
Where can I check the terms used in a GPR quote?
Our glossary explains them; learn about GPR, SUE & Land Survey Glossary entries such as QL-B, L-section and sonde.
Get a written quote to compare
Know what you are buying
Written by Saniya Parveen · Technically reviewed by Rahul Rai · Updated 8 November 2026