RTK GPS for Makers: Why Consumer GPS Drift Happens and How Correction Helps

Post by **Gensys** » Sat Aug 15, 2026 10:50 am

Consumer GPS is magical until you try to map a garden bed or guide a robot and watch the point jump several meters. That is not your module “being cheap” alone — it is physics, geometry, and atmospheric error.

GreatScott!’s RTK GPS project video is a friendly on-ramp into why real-time kinematic correction exists:

https://www.youtube.com/watch?v=y0UkxnTC1p4

Where consumer GPS error comes from

Satellite clock and orbit uncertainties
Ionosphere/troposphere delays
Multipath reflections near buildings
Limited constellation visibility under trees
Receiver noise and antenna quality

What RTK changes

RTK uses a base station at a known location (or a network base) to compute correction data for a rover. With a good fix, position error can drop from meters toward centimeter-class relative accuracy — transformative for surveying-style hobby projects, precision agriculture tinkering, and robotics.

Maker practicalities

RTK is a system (base + rover + correction link), not a single “better chip”
Antenna placement matters more than people want to admit
“Fix” vs “float” solution states are not the same thing
Power, radio link reliability, and sky view dominate weekend project success

Discussion

If you have tried RTK or high-precision GNSS on a budget, what correction source did you use — your own base, an NTRIP service, or something else — and how solid was it in the real world?