Tractor GPS — Coverage Recording on iPhone

Marea’s tractor GPS feature turns your iPhone into a fieldwork coverage tracker. Mount your phone in the cab, start a job, and Marea draws the area you’ve actually covered onto the field map as you drive. No more guessing where you’ve been or doubling back over the same strip.

What It Does

When you start a coverage session, Marea:

Reads your iPhone’s GPS continuously while you drive
Paints the worked area behind you onto the satellite map — at the width of your implement
Tracks total area covered in acres, hectares, square metres or your unit of choice
Highlights skips and overlaps so you can spot missed patches and reduce double-coverage
Saves the job so you can re-open it next time you’re in the field

The covered area is drawn live. Look down at the screen at any point and you can see exactly which strips you’ve already done.

When to Use It

This is built for any pass-by-pass fieldwork where missing strips or overlapping wastes time and inputs:

Ploughing — see uncovered headlands and skipped middles
Spraying — avoid double-spraying (saves chemical, prevents crop damage)
Seeding & drilling — keep rows even and don’t skip strips
Spreading fertiliser & lime — every overlap costs money
Mowing & topping — quick visual confirmation the whole field is done
Cultivating — make sure every strip’s been worked

It works with any tractor — old, new, big, small. There’s no controller to install, no harness, no autosteer. Just your phone.

Setting Up

Mount your phone somewhere you can see it from the seat (a £15 vent or window mount works fine)
Open Marea and start a new coverage session
Set your implement width — this controls how wide a strip Marea paints behind you
Tap Start as you enter the field
Drive normally — Marea paints behind you in real time
Tap Pause at the headland turn if you want; Stop when the job’s done

Marea saves the session with the date, the field, the implement width and the total area covered. Re-open it later to see the heatmap or export it.

Coverage Accuracy

Coverage strip width is set from your input — typically the working width of the implement (sprayer boom, seed drill, mower deck, plough). Marea draws a strip that wide centred on your GPS track.

For accuracy that matters:

iPhone GPS is good enough for most fieldwork. Modern iPhones use multi-constellation GNSS (GPS + GLONASS + Galileo + BeiDou) and typically deliver 3–5 metre accuracy in open fields. For most pass-by-pass work that’s tight enough to spot missed strips, but it’s not survey-grade.
For tight tramlines (under 3 m boom width), expect some visible drift between passes. Consider this a coverage aid, not a replacement for proper autosteer.
Bigger booms forgive GPS drift. A 24 m sprayer overlap budget is much bigger than the phone’s positioning error.

What It Doesn’t Do (Yet)

To be straight about it:

No autosteer / guidance lines. Marea shows you what you’ve done, not where to drive next. You steer; Marea records.
No section control. Marea doesn’t talk to your sprayer or seeder. It paints the strip you tell it to paint, even if you closed sections at the headland.
No RTK / cm-level precision. This is consumer GPS. Good for visual coverage, not for replacing pro guidance gear.

If you want a free coverage tracker that runs on the phone you already own, this is built for you. If you need autosteer with cm accuracy, you’re looking at John Deere, Trimble, AgLeader or similar.

Save, Review & Export

Every coverage session is saved to your Marea library with:

Field name and date
Total area covered
Implement width used
GPS track and painted coverage polygon

Export to KML to bring the coverage into Google Earth, QGIS, FieldView, John Deere Operations Center or any GIS tool. Hand a customer the actual coverage you applied — useful for contract spraying, custom drilling and contract mowing where billing matches area worked.

Free, with No Subscription to Start

Tractor GPS coverage recording is included in Marea on iOS. Download the app, set your implement width, and start your first session in under two minutes.

Android support is on the roadmap. iOS first because of the more consistent GNSS hardware across devices.

Field area measure — measuring field boundaries before you start the job
GPS land measurement — using GPS to measure land
Acreage calculator — calculating field acreage
KML export — exporting jobs to other software
GPS area calculator — general GPS area measurement

Try Marea Today

Download Marea on iOS or Android and start measuring in seconds.