What is RTK Accuracy? How Many Centimetres - Reliable or Fake?

RTK navigation provides accuracy of 1-3 cm horizontally and 2-5 cm vertically. This isn't fake, but a proven technology with a 20-year track record. According to 2025 research, 84% of RTK Fixed mode measurements show errors below 5 cm.

How RTK Works

Standard GPS has an error of 5-10 metres. RTK uses a base station that calculates signal errors and transmits corrections to the mobile receiver. Carrier phase analysis improves accuracy by 200-500 times compared to GPS.

The technology operates on L1, L2, and L5 frequencies, compensating for atmospheric distortions. The effective distance to the base station is up to 30-35 km.

Real Accuracy Figures

Based on professional equipment tests in 2024:

• Horizontally: 8 mm + 1 mm/km (at 10 km = 18 mm, at 30 km = 38 mm)
• Vertically: 15 mm + 1 mm/km (at 20 km = 35 mm)

The University of Illinois achieved errors below 50 mm in 50% of budget receiver tests. Australian research confirmed 2-8 cm in 76% of cases.

Influencing Factors

Equipment. Geodetic receivers (1400+ channels) deliver 1-2 cm. Consumer modules at 250-300 euros - 3-10 cm.

Distance. Up to 15 km - optimal (1-2 cm), 30 km - 3-4 cm, beyond 35 km - Float mode (10-50 cm).

Conditions. Open sky is ideal. Under trees - 1-2 m, near buildings - spikes up to 50 cm.

RTK Modes

• Fixed (1-3 cm): requires 5+ satellites
• Float (10-50 cm): works with 4 satellites
• DGPS (30-100 cm): backup mode

Practice Confirms Theory

Equipment tests: spacing between passes with RTK - 2-5 cm versus 30-50 cm without RTK. In Romanian forests, accuracy of 1.6-2 m in 30 seconds, which is 5-10 times better than GPS.

RTK is an ISO 17123-8 standard. Over 35 countries have RTK networks, commercial systems operate in Ukraine. With proper setup, 2 cm is reality.