In precision agriculture auto-guidance systems for tractors, Real-Time Kinematic (RTK) GNSS positioning achieves sub-inch pass-to-pass accuracy by using:
Options:
(A) Uncorrected standard civilian GPS L1 code-phase pseudo-ranges
(B) Carrier-phase differential corrections transmitted in real time from a local stationary base station or cellular network
- **RTK GNSS Principle:** Real-Time Kinematic positioning uses the high-frequency carrier wave phase (L1/L2/L5 bands) rather than binary pseudo-random code modulation.
- A local base station at a known surveyed benchmark calculates ionospheric and tropospheric delays in real-time and transmits differential phase corrections via radio/cellular link to the tractor rover, enabling horizontal accuracy within $\pm 2\text{ cm}$.