GPS and map accuracy

Turfile is a satellite-based map. Everything you place, every head, drain, bunker, and tree, sits on top of satellite imagery. That makes it worth a minute to understand how accurate that imagery is, so you know exactly what you’re working with.

Best practice: start from a drone survey

The best foundation you can give your map is an RTK-grade drone survey of your property, uploaded into Turfile before you start mapping. It’s not a requirement, just a good safety net, and it pays off in two ways:

• Survey-grade accuracy. An RTK survey is georeferenced to within centimetres. Map on top of it and everything you place lands exactly where it really is, with no satellite drift in the picture.
• A base map that never shifts. Satellite imagery gets refreshed over time, and when it does, its alignment can move slightly. Your mapped infrastructure doesn’t actually go anywhere, its coordinates stay the same, but it can start to look a little off against the new imagery. A survey you own stays exactly as it was flown, so your map always lines up.

You can order a drone survey directly through Turfile: open the Layers widget, click Manage layers, and choose Request imagery. Requesting drone imagery walks through the whole flow, from outlining the area you want flown to the finished imagery landing in your workspace as a layer. If you already have your own survey imagery, uploading it is covered in Managing your layers.

Your base map

Satellite imagery is georeferenced, meaning each pixel is tied to a real-world coordinate. In and around cities and developed areas, that referencing is usually spot on.

Out in more rural areas, where a lot of golf courses sit, it can be a little looser. The imagery itself is sharp, but its alignment to true coordinates can drift by a couple of metres. So a head you place dead on the satellite image might sit a metre or two off from its exact real-world position. For finding things and tracking work, that’s a non-issue. It’s just good to know it’s there.

Your phone’s GPS

When you’re out in the field placing things by your own location, keep in mind that phone GPS isn’t perfect either. It’s typically good to within a few metres, and it gets less precise under heavy tree canopy or right up against buildings. Give it a moment to settle when you’re dropping something by your position.

What’s coming

Turfile doesn’t yet connect to external RTK or GNSS receivers in the field, so you can’t currently pair a survey rover to place points at centimetre accuracy live. It’s something we’re actively working on. If you need it, let us know at support@turfile.com; that feedback helps us prioritize.