What is a DGPS Survey, and Why is it So Accurate?
The GPS in your phone is accurate to a few metres — fine for finding a road, but nowhere near enough to fix a plot boundary. Two people standing on the same corner with two phones can get readings five metres apart. On a 2-guntha plot, five metres is a serious amount of land.
This is where DGPS comes in.
What is DGPS?
DGPS stands for Differential Global Positioning System. It uses a base station at a known location together with a rover that moves around the site.
Satellite signals are distorted on the way down — by the ionosphere, by the atmosphere, by tiny timing errors in the satellites themselves. Because the base station is sitting on a point whose position is already known exactly, it can work out how wrong the satellites are at that moment, in that place. It sends that correction to the rover, which applies it to its own reading.
The result: positions accurate to within a few centimetres, repeatable day after day.
Ordinary GPS vs DGPS
| Ordinary GPS | DGPS | |
|---|---|---|
| Accuracy | 3–5 metres | A few centimetres |
| Corrections | None | From a base station or CORS network |
| Used for | Navigation | Surveying, demarcation, layout |
| Repeatable? | No — drifts between readings | Yes — same corner, same numbers |
| Accepted for legal / banking records | No | Yes |
In a land transaction, even a few centimetres can matter a great deal — which is exactly why DGPS is the standard for demarcation, and why a screenshot from a phone app is not a survey.
What DGPS is used for
- Plot demarcation — marking the exact boundaries and corners on the ground, the core of any jaga mojni.
- Layout marking / stake-out — transferring an approved layout onto the site, so roads and plots get built where the drawing says.
- Boundary and control surveys — establishing precise reference points that every later measurement on a large site is tied back to.
- GIS data collection — capturing utilities and assets in real-world coordinates, such as the drainage line GIS surveys PMC now asks contractors for.
- DGPS + drone — ground control points that make drone mapping survey-grade rather than merely pretty.
Where the corrections come from
There's more than one way to get the correction, and it matters:
- Your own base station. We set a base on site and the rover works against it. Reliable anywhere, including places with no mobile signal — which covers a lot of Maval, Mulshi and Bhor.
- A CORS network. Permanently operating reference stations broadcast corrections over the internet. No base to set up, but you need mobile data at the site, and for some certifications — such as the elevation certificate for PMC sanction — CORS specifically is what's required.
- PPK (post-processed kinematic). Readings are corrected afterwards in software rather than live. This is what we use for drone work, where the aircraft can't wait for a correction mid-flight.
When DGPS isn't the right tool
An honest surveyor tells you where the limits are.
DGPS needs a clear view of the sky. Under dense tree cover, between tall buildings, or inside a compound with high walls, the satellite signal degrades and accuracy falls away. In those conditions we use a Total Station, which measures angles and distances from a known point and doesn't care about satellites at all.
Most real sites use both: DGPS to establish accurate control points in the open, then a Total Station to work from those points into the awkward corners. Our drone vs total station guide covers how the three tools divide up the work.
What you receive
From a DGPS survey we deliver corner coordinates, a CAD drawing and an area statement — permit-ready deliverables suitable for banking, RERA and municipal approvals. Where the job needs it, we also provide the data as KML, shapefile or Excel.
Call now — +91 96577 17268Tap to speak to a surveyor directly.Common questions
How accurate is "a few centimetres", really?
For horizontal position, typically 1–3 cm under good conditions. Vertical accuracy is always looser than horizontal — usually about twice the number — so where levels matter, we say so and measure accordingly.
Can I just use a phone app instead?
No. Phone GPS has no correction source and no survey-grade antenna. It's off by metres, it isn't repeatable, and no bank, municipal office or court will accept it. It's a genuinely useful tool for finding a plot; it is not a tool for measuring one.
Does DGPS work everywhere in and around Pune?
Yes, with the right correction method. Built-up areas and dense canopy need more care, and that's where a Total Station comes in alongside it.
Do you own your equipment?
Yes — our own DGPS units and our own trained team, not hired in. That's why we can stand behind the accuracy of what we submit.
Need a DGPS survey?
Tell us the plot location and roughly how big it is, and we'll tell you which method suits the site, what it costs and when we can be there.
Call now — +91 96577 17268Tap to speak to a surveyor directly.You can also send the site details and we'll call you back.