AWARE: Locations

The locations sensor provides the best location estimate for the users’ current location, automatically. The location data is provided by Core Location.

Requirements

iOS 13 or later.

Installation

1. Open Package Manager Windows

   • Open Xcode -> Select Menu Bar -> File -> App Package Dependencies...

2. Find the package using the manager

   • Select Search Package URL and type https://github.com/awareframework/com.awareframework.ios.sensor.locations.git

3. Import the package into your target.

4. Add NSLocationAlwaysAndWhenInUseUsageDescription and NSLocationWhenInUseUsageDescription into Info.plist.

Public Functions

LocationsSensor

• init(config:LocationsSensor.Config?): Initializes the locations sensor with the optional configuration.
• start(): Starts the locations sensor with the optional configuration.
• stop(): Stops the service.

LocationsSensor.Config

Class to hold the configuration of the sensor.

Fields

• sensorObserver: LocationsObserver?: Callback for live data updates. (default = nil)
• sampleIntervalSeconds: Double: How often to check the location, in seconds. By default, every 180 seconds. (default = 180)
• accuracy: Int: the minimum acceptable accuracy of GPS location, in meters. By default, 100 meters. (default = 100)
• distanceFilter: Double: The minimum distance, in meters, before Core Location sends another standard location update. Set 0 to disable distance filtering. (default = 0)
• expirationTime: Int64: the amount of elapsed time, in seconds, until the location is considered outdated. By default, 300 seconds. (default = 300)
• saveAll: Bool: Whether to save all the location updates or not. (default = true)
• statusGps: Bool: Whether to use continuous GPS location tracking via startUpdatingLocation. (default = true)
• statusSignificantLocationChanges: Bool: Whether to also use significant-location-change monitoring as a background wake-up/recovery mechanism. Standard location updates remain enabled when statusGps is true. (default = true)
• enabled: Bool: Sensor is enabled or not. (default = false)
• debug: Bool: Enable/disable logging. (default = false)
• label: String: Label for the data. (default = "")
• deviceId: String: Id of the device that will be associated with the events and the sensor. (default = "")
• dbEncryptionKey: String?: Encryption key for the database. (default = nil)
• dbType: DatabaseType: Which db engine to use for saving data. (default = .none)
• dbPath: String: Path of the database. (default = "aware_locations")
• dbHost: String?: Host for syncing the database. (default = nil)

Broadcasts

Fired Broadcasts

• LocationsSensor.ACTION_AWARE_LOCATIONS: fired when new location available.
• LocationsSensor.ACTION_AWARE_GPS_LOCATION_ENABLED: fired when GPS location is active.
• LocationsSensor.ACTION_AWARE_GPS_LOCATION_DISABLED: fired when GPS location disabled.

Received Broadcasts

• LocationsSensor.ACTION_AWARE_LOCATIONS_START: received broadcast to start the sensor.
• LocationsSensor.ACTION_AWARE_LOCATIONS_STOP: received broadcast to stop the sensor.
• LocationsSensor.ACTION_AWARE_LOCATIONS_SYNC: received broadcast to send sync attempt to the host.
• LocationsSensor.ACTION_AWARE_LOCATIONS_SET_LABEL: received broadcast to set the data label. Label is expected in the LocationsSensor.EXTRA_LABEL field of the intent extras.

Data Representations

Locations Data

Contains the locations profiles.

Field	Type	Description
latitude	Double	The latitude in degrees.
longitude	Double	The longitude in degrees.
course	Double	The direction in which the device is traveling, measured in degrees and relative to due north.
speed	Double	The instantaneous speed of the device, measured in meters per second.
altitude	Double	The altitude, measured in meters.
floor	Int	The logical floor of the building in which the user is located.
horizontalAccuracy	Double	The radius of uncertainty for the location, measured in meters.
verticalAccuracy	Double	The accuracy of the altitude value, measured in meters.
deviceId	String	AWARE device UUID
label	String	Customizable label. Useful for data calibration or traceability
timestamp	Int64	Unixtime milliseconds since 1970
timezone	Int	Timezone of the device
os	String	Operating system of the device (e.g., ios)
jsonVersion	Int	JSON schema version

Heading Data

Contains compass/heading data.

Field	Type	Description
magneticHeading	Double	The heading (in degrees) relative to magnetic north.
trueHeading	Double	The heading (in degrees) relative to true north.
headingAccuracy	Double	The maximum deviation (in degrees) between reported and true heading.
x	Double	The geomagnetic data (x-axis) measured in microteslas.
y	Double	The geomagnetic data (y-axis) measured in microteslas.
z	Double	The geomagnetic data (z-axis) measured in microteslas.
deviceId	String	AWARE device UUID
label	String	Customizable label. Useful for data calibration or traceability
timestamp	Int64	Unixtime milliseconds since 1970
timezone	Int	Timezone of the device
os	String	Operating system of the device (e.g., ios)
jsonVersion	Int	JSON schema version

Location Event Data

Contains Core Location lifecycle events, including authorization changes, failures, and pause/resume callbacks.

Field	Type	Description
eventType	String	Event type: authorization_changed, failed, paused, or resumed.
message	String	Human-readable event detail.
errorDomain	String	Error domain for failure events.
errorCode	Int	Error code for failure events.
authorizationStatus	String	Current Core Location authorization status.
accuracyAuthorization	String	Current accuracy authorization on iOS 14 and later.
latitude	Double	Last known latitude, if available.
longitude	Double	Last known longitude, if available.
horizontalAccuracy	Double	Last known horizontal accuracy, if available.
deviceId	String	AWARE device UUID
label	String	Customizable label. Useful for data calibration or traceability
timestamp	Int64	Unixtime milliseconds since 1970
timezone	Int	Timezone of the device
os	String	Operating system of the device (e.g., ios)
jsonVersion	Int	JSON schema version

Example Usage

// To initialize the sensor
let locationSensor = LocationsSensor.init(LocationsSensor.Config().apply { config in
    config.sensorObserver = Observer()
    config.debug = true
    config.dbType = .sqlite
    // more configuration...
})
// To start the sensor
locationSensor?.start()

// To stop the sensor
locationSensor?.stop()

class Observer:LocationsObserver {
    func onLocationChanged(data: LocationsData) {
    // your code here
    }
}

Author

Yuuki Nishiyama (The University of Tokyo), nishiyama@csis.u-tokyo.ac.jp

Related Links

• Apple | Core Location
• Apple | CLLocation

License

Copyright (c) 2025 AWARE Mobile Context Instrumentation Middleware/Framework (http://www.awareframework.com)

Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at

http://www.apache.org/licenses/LICENSE-2.0 Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.