The AG-820 integrates receiver, radio modem, and tilt sensor into a single weatherproof roof mount, eliminating the separate receiver box and cable management of earlier systems. Trimble CenterPoint RTX correction service delivers 15 cm global accuracy on a satellite subscription without a local base station, covering fields with no cellular or local RTK service. Terrain Compensation uses the tilt sensor to correct position errors when the tractor traverses hillside furrows, maintaining row-to-row accuracy in rolling terrain. CANbus output sends steering commands directly to compatible auto-steer valves on John Deere, AGCO, and CNH tractors using OEM integration kits.