Guide · GNSS & survey
Survey of India CORS: registration, subscription and NRTK setup
How to register on the Survey of India CORS portal, choose a plan, connect a rover and check your results. Reviewed on 30 October 2026 against the official portal.
Uday GeoAnalytics Consultancy Private Limited is not affiliated with Survey of India. Rates, IP addresses and procedures change; the Survey of India CORS portal is the authoritative source.
Survey of India operates a national network of Continuously Operating Reference Stations (CORS). Its services let surveyors get real-time corrections in the field, download reference data and process static observations against the network. This guide brings the official steps together and adds the field checks we use before a coordinate goes into a deliverable.
What the CORS network offers
| Service | What it gives you | Stated accuracy | You need |
|---|---|---|---|
| Network RTK (NRTK) | Real-time corrections for centimetre-level relative positioning | 3–4 cm (relative), with best practices | RTK-enabled GNSS rover, internet at site |
| DGNSS | Real-time differential corrections | 30–40 cm (relative), with best practices | DGNSS-enabled rover, internet at site |
| Reference Data Services (RDS) | Download past CORS data; generate virtual RINEX at a location in the network | Depends on your processing | Your own static observations and processing software |
| Online GNSS Processing (OPS) | Process your geodetic-receiver observations against the CORS network on the portal | Depends on data quality and duration | RINEX observations from a geodetic receiver |
Who pays, and how much
Registration is free. A subscription is needed for each service you use. The portal lists Central Government users, State Government users and Government academic institutions as eligible for free subscriptions. PSU and private users buy a plan through the portal.
| Plan | Validity / limit | Total (₹) |
|---|---|---|
| RTK1 | Unlimited NRTK, 1 month | 5,900 |
| RTK3 | Unlimited NRTK, 3 months | 17,700 |
| RTK6 | Unlimited NRTK, 6 months | 35,400 |
| RTK12 | Unlimited NRTK, 1 year | 70,800 |
| DGNSS1 | Unlimited DGNSS, 1 month | 2,360 |
| DGNSS12 | Unlimited DGNSS, 1 year | 28,320 |
| RDS6 | Data download up to 3,60,000 epochs (about 100 hours at 1 s) | 566 |
| OPS1 | Online processing up to 36,000 epochs (about 10 hours at 1 s) | 212 |
Combined plans are also listed, for example NRTK with data download, or NRTK with online processing. See Survey of India CORS subscription charges for the full list.
How to register on the CORS portal
- Open the registration form at cors.surveyofindia.gov.in/registration and enter your name, address, mobile number, email and organisation.
- Download the annexures (PDF) from the portal, fill and sign them.
- Upload the annexures with copies of your personal and organisational ID cards. This is the KYC step.
- Wait for approval of the registration, then log in.
- Buy or request a subscription for NRTK, DGNSS, data download or online processing. Government users follow the free-subscription route.
The portal publishes a revised SOP for CORS registration. Read it before you start, because it lists the current documents.
Connecting your rover to Survey of India NRTK
Find your region on the portal’s region map first. Then enter these settings in your controller’s NTRIP client, with the username and password from your subscription:
| Region | IP address | Port |
|---|---|---|
| Region 1 | 103.205.244.106 | 2101 |
| Region 2 | 103.206.29.4 | 2105 |
The portal notes that Region 2 corrections moved to 103.206.29.4 from the earlier 43.240.5.42. If an older controller profile stops connecting, check this first. Each login gives one stream at a time; two rovers working together need two logins.
Field settings the portal asks for
- Use an RTK-enabled GNSS receiver and confirm mobile data coverage across the project area.
- Set the elevation mask to 10–15 degrees and the minimum tracked satellites to six.
- Plan survey times with mission-planning software and keep receiver firmware current.
- Record only fixed solutions. Set the receiver’s QC threshold slightly tighter than the project accuracy requirement.
Checks we add before a coordinate is used
A fixed solution on the controller is not, by itself, evidence that a point is right. Before NRTK results go into a drawing or a report, we recommend:
- Occupy a known control point at the start and end of the day and compare against its published value.
- Re-observe a sample of points at a different time of day, so satellite geometry changes between the two fixes.
- Keep the metadata: mountpoint, reference frame and epoch, antenna height and type, fix status, PDOP and number of satellites for each point.
- Confirm the coordinate reference your client needs, and document any transformation from the CORS reference frame. A wrong datum or epoch can shift a whole project.
NRTK, DGNSS or static post-processing?
Use NRTK when you need centimetre-level positions in real time and have mobile coverage. Use DGNSS for mapping and asset location where decimetre-level positions are enough. Use static observations with Reference Data Services or online processing for control points, long baselines, or sites without reliable mobile data. Longer sessions give more reliable static results.
Common problems
- Cannot connect: check the region, IP address and port, and whether another device is already using the same login.
- Float solution that will not fix: check sky view, multipath from walls and trees, elevation mask and mobile signal.
- Results disagree with old drawings: compare the datum and epoch of both datasets before treating it as a field error.
Frequently asked questions
Is Survey of India CORS registration free?
Yes. Registration on the CORS portal is free for Indian entities and needs an online form and KYC documents. Using a service needs a subscription.
Who gets a free CORS subscription?
The portal lists Central Government users, State Government users and Government academic institutions as eligible for free subscriptions. PSU and private users buy a paid plan.
What accuracy does Survey of India NRTK give?
The portal states a relative positioning accuracy of 3–4 cm for Network RTK and 30–40 cm for DGNSS, when best practices are followed. Your result still depends on your receiver, site conditions and field method.
Can one CORS login be used on two rovers at the same time?
No. Each login gives one stream at a time. Using two or more devices together needs multiple logins.
Which IP address and port should I use?
The portal lists Region 1 as 103.205.244.106, port 2101, and Region 2 as 103.206.29.4, port 2105. Check the region map on the portal first, because these settings can change.
Can I download CORS RINEX data for post-processing?
Yes. Reference Data Services let subscribers download past CORS data and generate virtual RINEX within the network, subject to the epoch limit of the plan.
Need a second check on CORS-based survey data?
We review GNSS observations, processing choices and coordinate references, and prepare a quality record that explains what the results can and cannot support. See our GNSS processing and survey QA service or send us your project details.
Sources
- Survey of India CORS portal: registration, subscription and connection settings
- Services offered by the Survey of India CORS network
- CORS subscription charges
- Requirements at user end
- Revised SOP for CORS registration (PDF)
Last reviewed on 30 October 2026.