Ingredient
GPS-RTK
Also known as: Real-Time Kinematic GNSS, centimeter-precision GPS, u-blox ZED-F9P
Real-Time Kinematic positioning — high-precision satellite navigation that uses carrier-phase measurements and a nearby base-station correction stream to produce centimeter-accurate positions instead of the meter-accurate fixes of standard GPS. The right ingredient for any outdoor autonomous machine that needs to know where it is on a field with row-precision: autonomous tractors, weed-spraying rovers, transplanting robots, drone-precision mapping. Works by combining a *rover* receiver with a *base* receiver streaming RTCM corrections (NTRIP over cellular or local radio); some networks (NTRIP casters) provide free public correction streams. u-blox ZED-F9P boards run ~$200; full RTK base+rover kits ~$500–1000.
Inputs / outputs
- Frequency bands: L1, L2 (multi-band receivers like ZED-F9P do better than single-band)
- Output: NMEA sentences (GGA, GSV, etc.) over UART, USB, or I²C; or u-blox UBX binary
- Position accuracy: cm-level with RTK fix; ~1 m without correction
- Update rate: 1–25 Hz typical
- Power: ~100 mA active
Solves / unlocks
- Autonomous-rover row-following with cm-precision (no row-camera needed if RTK is reliable)
- Automated transplanting on geo-located plant spacing
- Precision drone mapping (geo-tagged images for orthomosaic generation)
- Field-boundary recording with surveyor-grade accuracy
- Multi-machine coordination (synchronized passes by sub-meter offset)
Constraints
- Sky-view dependent — RTK fix needs clear sky; tree canopy blocks satellite signals.
- Base station required — within ~10–20 km of rover; or use NTRIP casters (need cellular data).
- Settling time — initial RTK-fix acquisition takes 30 seconds to several minutes.
- Multipath — reflective surfaces (metal buildings, water) degrade accuracy.
- Cost versus standard GPS — 10× more expensive for cm vs meter accuracy.
Source
- u-blox ZED-F9P: https://www.u-blox.com/en/product/zed-f9p-module
- ArduSimple kits: https://www.ardusimple.com/
- RTKLIB (open-source RTK processing): https://github.com/tomojitakasu/RTKLIB (BSD)
- NTRIP casters: https://www.rtcm-ntrip.org/
See also
Auto-generated from this entry’s typed relations: frontmatter, grouped by relation type so the editorial signal isn’t flattened.
- Member of: [[ingredient]]
- Combines with: [[ros2]] · [[acorn-rover]] · [[nvidia-jetson]] · [[imu-mpu6050]] · [[lorawan]]
What links here, and how
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Practical
contains
- Farm-tech toolkit sensor / centimeter-precision outdoor positioning
combines with
- IMU (MPU6050 / BNO085) RTK-GPS gives position; IMU gives orientation; fused via EKF they give pose
- Meshtastic T-Beam boards include GPS; mesh nodes share position for crew tracking and asset location
- PX4 / ArduPilot autopilot Pixhawk + RTK-GPS = cm-precision drone for orthomosaic mapping and precise spray missions
combines
- Recipe: autonomous row-crop weeder row-following at cm precision; fallback when computer vision uncertain
- Recipe: livestock & equipment tracking mesh GPS for position; cm-precision unnecessary for cattle but useful for equipment-recovery
- Recipe: NDVI crop-scouting drone cm-precision geotagging for accurate orthomosaic stitching
7 inbound links · 6 outbound