Gate Mapper AR: measure a ski course with one phone

Professional teams can survey a course with RTK/GNSS and achieve higher positional accuracy, but that requires specialist hardware. A tape measure may handle straight-line distance; recording every interval together with lateral offset and vertical change—and turning it into a reusable course map—is not realistic for everyday training.

Gate Mapper AR makes that workflow possible with one phone.

One gate, a few seconds

AI detects the top of the gate and its contact point with the snow. The app converts the gate's apparent height on screen into an angle, then uses the known gate height and a camera field of view calibrated for that phone to solve the distance with trigonometry. Device pitch estimates vertical change; the operator confirms course direction so the app can calculate offset.

Center the gate, hold the phone still, and automatic recognition can record distance and vertical change in a few seconds per gate. If recognition is uncertain, the same screen is immediately available for manual measurement.

Gate Mapper AR automatically measuring a red GS gate on snow — AI has recognized the gate top and snow contact point and confirmed a 30.8 m distance.

MAP and Data, immediately

Every accepted measurement is added to the MAP and Data views. Distance, offset, slope change and course rhythm remain visible instead of disappearing into field notes.

The MAP shows course rhythm together with the elevation profile.

Gate Mapper AR Data table showing distance, angle, offset and slope — The Data view keeps each gate's measurements available for analysis.

Practice data can reveal recurring patterns and guide countermeasures. The same information can support discussion of line choice and speed strategy before a race.

Preview the measured course in Run No.0

Export the course as .gmap.json and open it in Run No.0. The measured set becomes a first-person 3D preview that is easier to remember and discuss.

A measured GS course opened as a first-person 3D preview in Run No.0 — The same measured GS course viewed from the athlete's perspective in Run No.0.

The safety idea is deliberately modest: make an unfamiliar course a little less unfamiliar. A clearer pre-run picture may reduce delayed reactions and rushed decisions when the rhythm changes. Research on slalom visual behaviour found that expert skiers maintained a larger visual buffer and looked farther ahead, which supports this pathway—but does not prove that Gate Mapper reduces injuries. Read the study.

Gate Mapper is not a replacement for official FIS surveying, RTK measurement or on-snow course inspection. Results depend on device calibration, sensors, weather, visibility and how the phone is held.

Measure it. See it. Rehearse it.

Measure the course with Gate Mapper AR, then preview the same data in Run No.0.

Open Gate Mapper AR Open Run No.0

Questions, requests or ideas? Send me a DM on Instagram!