# Positions

Last updated:

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October 18, 2026

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\| 4 minutes read

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This page covers position data representation using `GemPosition` and `GemImprovedPosition` classes for GPS-based systems.

tip

Don't confuse `Coordinates` with `Position` classes. The `Coordinates` class represents geographic locations (latitude, longitude, altitude) and is widely used throughout the SDK. In contrast, `GemPosition` and `GemImprovedPosition` classes contain additional sensor data and primarily represent the user's location and movement details.

## Create positions[​](#create-positions "Direct link to Create positions")

Instantiate the `GemPosition` class using methods in the `SenseDataFactory` class. You can also access it through methods exposed by the Maps SDK for Flutter.

For more details, refer to the [Get Started with Positioning](/docs/flutter/guides/positioning/get-started-positioning.md) guide.

## Raw position data[​](#raw-position-data "Direct link to Raw position data")

Raw position data represents unprocessed GPS sensor data from devices. It corresponds to the `GemPosition` interface.

## Map matched position data[​](#map-matched-position-data "Direct link to Map matched position data")

Map matching aligns raw GPS data with a digital map, correcting inaccuracies by snapping the position to the nearest logical location (such as roads). It corresponds to the `GemImprovedPosition` interface.

## Compare position types[​](#compare-position-types "Direct link to Compare position types")

Map matched positions provide more information than raw positions:

| Attribute            | Raw | Map Matched | When is available     | Description                                                                                                           |
| -------------------- | --- | ----------- | --------------------- | --------------------------------------------------------------------------------------------------------------------- |
| acquisitionTime      | ✅  | ✅          | always                | The system time when the data was collected from sensors.                                                             |
| satelliteTime        | ✅  | ✅          | always                | The satellite timestamp when position was collected by the sensors.                                                   |
| provider             | ✅  | ✅          | always                | The provider type (GPS, network, unknown)                                                                             |
| latitude & longitude | ✅  | ✅          | hasCoordinates        | The latitude and longitude at the position in degrees                                                                 |
| altitude             | ✅  | ✅          | hasAltitude           | The altitude at the given position. Might be negative                                                                 |
| speed                | ✅  | ✅          | hasSpeed              | The current speed (always non-negative)                                                                               |
| speedAccuracy        | ✅  | ✅          | hasSpeedAccuracy      | The current speed accuracy (always non-negative). Typical accuracy is 2 m/s in good conditions. Not available on web. |
| course               | ✅  | ✅          | hasCourse             | The current direction of movement in degrees (0 north, 90 east, 180 south, 270 west)                                  |
| courseAccuracy       | ✅  | ✅          | hasCourseAccuracy     | The current heading accuracy is degrees (typical accuracy is 25 degrees). Not available on web.                       |
| accuracyH            | ✅  | ✅          | hasHorizontalAccuracy | The horizontal accuracy in meters. Always positive. (typical accuracy 5-20 meters)                                    |
| accuracyV            | ✅  | ✅          | hasVerticalAccuracy   | The vertical accuracy in meters. Always positive.                                                                     |
| fixQuality           | ✅  | ✅          | always                | The accuracy quality (inertial – based on extrapolation, low – inaccurate, high – good accuracy, invalid – unknown)   |
| coordinates          | ✅  | ✅          | hasCoordinates        | The coordinates of the position                                                                                       |
| roadModifiers        | ❌  | ✅          | hasRoadLocalization   | The road modifiers (such as tunnel, bridge, ramp, etc.)                                                               |
| speedLimit           | ❌  | ✅          | always                | The speed limit on the current road in m/s. It is 0 if no speedLimit information is available                         |
| terrainAltitude      | ❌  | ✅          | hasTerrainData        | The terrain altitude in meters. Might be negative. It can be different than altitude                                  |
| terrainSlope         | ❌  | ✅          | hasTerrainData        | The current terrain slope in degrees. Positive values for ascent, negative values for descent.                        |
| address              | ❌  | ✅          | always                | The current address.                                                                                                  |

Web

On web, position data comes from the browser [Geolocation API](https://developer.mozilla.org/docs/Web/API/Geolocation_API) rather than raw device sensors. As a result:

* `speedAccuracy` and `courseAccuracy` are never available.
* `altitude`, `accuracyV`, `course`, and `speed` may be null depending on the device and browser.

info

The `speedLimit` field may not always have a value, even if the position is map matched. This can happen if data is unavailable for the current road segment or if the position is not on a road. In such cases, the `speedLimit` field will be set to 0.

tip

To check if a user is exceeding the legal speed limit, use the `AlarmService` class. Refer to the [speed warnings guide](/docs/flutter/guides/alarms/speed-alarms.md) for more details.