During an indoor positioning survey, a device records Bluetooth Low Energy (BLE) or WiFi radio signals from the environment. Simultaneously, motion unit sensors provide additional input that is used for optimization of position estimations. The sensors must be calibrated for optimal performance. A built-in sensor check warns if one or more sensors are not calibrated or if required permissions are not granted.
Use the Sensors section in the user profile to verify the app permissions and the status of Bluetooth, location, compass, gyroscope, and accelerometer sensors. To access the Sensors section, tap the Profile button at the top of the map list.
The IPS Setup app includes support for both Bluetooth and WiFi. You can configure the data type to use for a survey in the Configuration section of the Profile page under Network. If you select WiFi, the Sensors list expands to include WiFi and WiFi Scanning Throttling options.
Verify app permissions
Verify app permissions by completing the following:
- Tap Profile
. The status of sensors are displayed in the Sensors section.
- Ensure that the following permissions are enabled:
- Location
- Google Location Accuracy
- Compass Calibration
- Bluetooth
Additionally, if Wi-Fi is selected as the option for Survey Radio Type:
- WiFi
- WiFi Scanning Throttling
Note:
The Wi-Fi scan throttling is enabled by default on Android devices and can be disabled in the developer mode. Learn more about configuring the Wi-Fi scanning throttling.
Verify compass accuracy
Use your device's compass to determine its heading. Compass accuracy is the deviation between the reported heading and the true geomagnetic heading.
Note:
Due to hardware variations among Android devices, the compass does not always satisfy the optimal performance requirements. Compass accuracy can register one of the following four states:
- High—The status is displayed as OK in green.
- Medium—The status is displayed as Medium in orange.
- Low—The status is displayed as Low in yellow.
- Poor/Unreliable—The status is displayed as Calibrate in red.
If the compass accuracy is high, medium, or low, you can perform a survey. If the compass accuracy is poor, calibrate the compass before conducting a survey.
To calibrate the compass of your device, complete the following steps:
- Open IPS Setup and sign in if necessary.
- Tap Profile at the top of the map list screen.
If the compass accuracy is poor, a request to calibrate it will appear in red. Calibrate the compass by moving the phone in a figure eight shape and pull down on the screen to refresh the status. If the accuracy is high, calibration is not necessary. When it is medium or low, calibration is optional, but recommended.
Alternatively, after loading a map from the list, tap the Sensor Check status bar when shown at the top of the map mode. The Sensor Check bar only appears in the map, survey, and test modes if one or more sensors are not calibrated, or if required permissions are not granted.
You can calibrate the compass at any time without accessing the Sensor Check list.
Note:
If your survey device is not equipped with a compass or a gyroscope, it may not meet sensor calibration requirements. If this is the case, switch to a device that is equipped with these sensors to successfully collect the necessary data.
Regardless of the compass accuracy, you can still access the Test mode of the IPS Setup app.
Configure Wi-Fi scan throttling
The IPS Setup app includes support for Wi-Fi and Bluetooth. You can configure the Survey Radio Type in the Configuration section of the Profile page under Network.
Note:
The app supports the Wi-Fi recorder data type on Android 10 and later.
After selecting Wi-Fi as the option for Survey Radio Type, the WiFi Scanning Throttling option appears in the Sensors section. The Wi-Fi throttling is enabled by default on Android devices. This means that each foreground app can scan four times in a two-minute period, allowing for a burst of scans in a short time, and background apps can scan once in a 30-minute period.
Learn more about the Wi-Fi scan throttling settings
To record Wi-Fi sensor data, you must disable Wi-Fi scanning throttling.
To disable Wi-Fi scan throttling, complete the following steps:
- Enable developer options on the Android device.
Once enabled, Developer options appear in the device's Settings app.
- Choose Developer options and turn off Wi-Fi scan throttling.
- Return to the IPS Setup app and ensure that WiFi Scanning Throttling is disabled.
Path snapping
During preparation of maps for survey and testing, you can configure pathways to enable path snapping functionality for their map. If pathways are configured for path snapping, the functionality is enabled by default. After the survey has been completed and reference positioning data is created, the positioning testing is performed. Optionally, during the positioning testing, you can compare the blue dot accuracy with the path snapping feature enabled and disabled. You can enable and disable the feature by turning Path Snapping on or off in the profile menu.
Turn Show Paths on to visualize the Pathways feature class.
Tip:
If you are surveying a facility that you are not familiar with, you can turn on Show GPS Location to enable the GPS location in Map mode. This functionality displays GPS location in Plan mode until the first survey point of planned survey path is specified. When available indoors, GPS location can help determine your approximate location before planning and surveying.