RTK GPS for Drone Survey in India: A Practical Buyer's Guide (2026)
Drone survey work is growing quickly across India – land records, mining volumetrics, solar sites, road corridors and agriculture all use it – and clients now ask for centimetre-level results that a standard GPS module cannot deliver. This guide explains how RTK GPS for drones works, what you need around it, what to look for in a module and what RTK GNSS modules cost in India in 2026.
Updated 15 November 2026 · Aerostem engineering team
RTK vs standard GPS: what is the difference?
A standard GNSS receiver calculates its position from satellite signals alone. Atmospheric delay, satellite clock and orbit errors and signal reflections all add error. In practice, a typical drone GPS is accurate to a few metres horizontally. That is fine for Loiter and Return-to-Launch, but not for mapping.
RTK (Real-Time Kinematic) adds a second receiver at a known, fixed point. This is the base station, or a correction service that does the same job. The base works out the errors it sees and streams correction data to the drone (the rover) in real time. Both receivers see nearly the same errors, so the rover can cancel most of them. Under good conditions, RTK systems usually reach centimetre-level relative accuracy.
| Standard GNSS | RTK GNSS | |
|---|---|---|
| Typical horizontal accuracy | A few metres | Centimetre-level (when "RTK Fixed") |
| Needs corrections? | No | Yes (base or NTRIP) |
| Best for | Navigation, hobby flying | Survey, mapping, precision landing |
| Cost | Low | Higher |
Figures are typical industry ranges. Actual accuracy depends on the receiver, antenna, sky view, baseline length and correction quality.
RTK Fixed vs RTK Float
Your ground station will show one of two RTK states. RTK Fixed means the receiver has resolved its position to centimetre level. RTK Float means it is using corrections but has not fully converged, and accuracy is usually at decimetre level. For survey work, only capture data while the receiver shows Fixed.
What about PPK?
PPK (Post-Processed Kinematic) applies the same corrections after the flight, using logged raw data. Teams often choose it where the radio link or internet coverage is unreliable. Many survey teams use both, or add ground control points (GCPs) to check the results.
Where do RTK corrections come from?
Option 1: Your own base station
You set up a second RTK receiver on a tripod over a known point, or let it "survey-in" its own position. It sends corrections to the drone through the telemetry radio. In ArduPilot's Mission Planner, the RTK/GPS Inject screen sends base-station corrections over MAVLink.
- Pros: works anywhere, including remote mines and farms with no mobile signal.
- Cons: you need a second receiver, so cost goes up, along with setup time.
Option 2: NTRIP (network corrections)
NTRIP streams corrections over the internet from a reference station or a network of them (CORS). Your laptop or ground station receives the stream on a mobile connection and forwards it to the drone. Mission Planner can connect to an NTRIP caster directly. In India, the Survey of India runs a national CORS network, and private networks are also appearing; check current access terms with the provider before you plan a job around them.
- Pros: no base hardware to carry, and survey-grade reference positions.
- Cons: you need mobile data in the field, accuracy drops as you move further from the reference station, and subscriptions may apply.
What to look for in an RTK GNSS module
- RTK support and correction format. Check that the module accepts the corrections your workflow uses (usually RTCM3) and that your flight stack supports it. ArduPilot and PX4 both support RTK GPS.
- Constellations and bands. Multi-constellation receivers (GPS, GLONASS, Galileo, BeiDou, NavIC where supported) see more satellites. Multi-band (L1/L2/L5) receivers usually reach a Fix faster and hold it better.
- Update rate. 5–10 Hz or more helps the autopilot and gives smoother position data.
- Integrated compass quality. A good magnetometer, such as the PNI RM3100, which many builders prefer for its low noise, gives more reliable heading.
- Interface. Check whether the module uses UART + I²C or CAN/DroneCAN, and whether its connector matches your flight controller.
- Base capability. Find out whether the same module can also work as your base station.
- Local support and documentation. Look for pinouts, datasheets, firmware files and an Indian GST invoice.
RTK GNSS module price in India (2026)
The figures below are listed prices we observed for popular RTK options sold in India. Prices change often, so check with each seller.
| Product | Indicative price (INR) | Notes |
|---|---|---|
| Aero A20 RTK GNSS (Aerostem) | ₹16,000 + GST | RTK, 10 Hz, RM3100 compass, made in India |
| Aeroatoms Orbit Nano RTK | ₹20,999 | Indian brand, compact RTK module |
| Here RTK kit (CubePilot ecosystem) | ₹21,712 | Widely used with Cube autopilots |
| u-blox ZED-F9P-based boards | from ₹23,599 | Popular multi-band chipset, many vendors |
Prices seen on Indian retailer listings in November 2026; check current prices before buying.
Typical range: most RTK modules for drones in India sell for ₹16,000–₹27,000 each. Remember that a full RTK setup may need a second unit as a base, unless you use NTRIP.
Every product listed here has users who rely on it. The right choice depends on your autopilot, the accuracy you need, your interface and your budget. Compare the published specs side by side before you decide.
Where the Aero A20 RTK GNSS fits
The Aero A20 RTK GNSS is Aerostem's satellite-navigation module. It offers:
- RTK positioning using correction data
- 10 Hz position output
- An integrated RM3100 compass
It is priced at ₹16,000 + GST, with volume tiers of ₹15,167 (11–49), ₹14,333 (50–99) and ₹13,500 (100+), all + GST. Aerostem designs and manufactures it in India, and every order comes with a GST invoice.
If you are building on the Aero H743 Flight Controller, its GPS connector carries UART3 + I²C, and its datasheet lists u-blox F9P-class RTK modules as a supported type. Ask Aerostem to confirm wiring for your specific setup.
Not yet published, so ask Aerostem: positioning accuracy, weight, GNSS bands, interface and whether the A20 can act as a base. Contact the team to confirm the module suits your survey workflow before you buy.
Getting the best drone survey accuracy
RTK is only one part of drone survey accuracy. These steps help you get the most from it:
- Mount the antenna well. Put it high, with a clear view of the sky, away from the VTX, power wires and carbon plates.
- Wait for RTK Fixed before take-off, and watch for drops back to Float during the mission.
- Keep baselines short. Accuracy falls as the drone moves further from the base or reference station.
- Account for camera timing. Geotag accuracy depends on camera-trigger timing and the antenna-to-camera offset, not only on the GNSS module.
- Use check points. Even with RTK, a few GCPs or check points show your client that the accuracy figures are real.
- Stay compliant. Follow India's Drone Rules and Digital Sky requirements for your operating zone.
Setting up the flight controller side? Read our Aero H743 ArduPilot setup guide.
Frequently asked questions
What accuracy can RTK GPS give a drone survey?
Under good conditions, RTK systems usually reach centimetre-level relative accuracy once the receiver shows "RTK Fixed". Real-world results depend on the receiver, antenna placement, sky view, baseline length and the quality of the corrections.
How much does an RTK GNSS module cost in India?
In 2026, RTK modules for drones in India are listed at roughly ₹16,000–₹27,000 each. The Aero A20 RTK GNSS is ₹16,000 + GST. A full setup may also need a base station, unless you use NTRIP corrections.
Do I need a base station for RTK, or can I use NTRIP?
Either works. A base station gives you corrections anywhere, with no internet needed. NTRIP streams corrections from a reference network over mobile data, so you carry no base hardware, but you need coverage in the field.
Is RTK the same as PPK?
No. RTK applies corrections in real time during the flight. PPK applies them afterwards using logged data. Both can reach survey-grade accuracy, and many teams use them together with ground control points.