21.2. Urmărirea live a GPS-ului
There are three possible screens in this GPS tracking window:
Options:GPS options screen (see Fig. 21.5)
With a plugged-in GPS receiver (has to be supported by your operating system), a simple click on Connect connects the GPS to QGIS. A second click (now on Disconnect) disconnects the GPS receiver from your computer. For GNU/Linux, gpsd support is integrated to support connection to most GPS receivers. Therefore, you first have to configure gpsd properly to connect QGIS to it.
With the Recenter button the map will jump to the current GPS position.
If you want to record your position to the canvas, you have to create a new vector layer first and switch it to editable status to be able to record your track.
When a GPS device is connected and the user moves the cursor over the map canvas, a live status bar message displays the distance and bearing from the cursor to the GPS position. Project distance and bearing settings are respected in this display.
Touch Screen Devices
On a touch screen device use a tap-and-hold event to trigger the live status bar message.
Here you can specify:
The Calculate bearing from travel direction can be used if the device reports faulty bearing measurements and it will calculate the GPS bearing based on the previous two recorded locations.
Cursor: you can use a slider to shrink and grow the position cursor on the canvas.
Filtering: You can also set an Acquisition interval (seconds) and a Distance threshold (meters) parameters to keep the cursor still active when the receiver is in static conditions.
Map Centering and Rotation
Activating Map centering allows you to decide in which way the canvas will be updated. This includes «always», «when leaving», if your recorded coordinates start to move out of the canvas, or «never», to keep map extent.
Activating Rotate map to match GPS direction will automatically rotate the map canvas so that it is oriented in the same direction as the GPS bearing.
Activating Show Bearing Line will show a line from the GPS location pointing in current path direction of the GPS.
With QGIS you can connect a Bluetooth GPS for field data collection. To perform this task you need a GPS Bluetooth device and a Bluetooth receiver on your computer.
At first you must let your GPS device be recognized and paired to the computer. Turn on the GPS, go to the Bluetooth icon on your notification area and search for a New Device.
On the right side of the Device selection mask make sure that all devices are selected so your GPS unit will probably appear among those available. In the next step a serial connection service should be available, select it and click on Configure button.
Rețineți numărul portului COM atribuit conexiunii GPS, după cum rezultă din proprietățile Bluetooth.
După ce GPS-ul a fost recunoscut, creați asocierea pentru conexiune. De obicei, codul de autorizare este
Now open GPS information panel and switch to GPS options screen. Select the COM port assigned to the GPS connection and click the Connect. After a while a cursor indicating your position should appear.
If QGIS can’t receive GPS data, then you should restart your GPS device, wait 5-10 seconds then try to connect again. Usually this solution work. If you receive again a connection error make sure you don’t have another Bluetooth receiver near you, paired with the same GPS unit.
Easiest way to make it work is to use a middleware (freeware, not open) called GPSGate.
As for Windows the easiest way is to use a server in the middle, in this case GPSD, so
sudo apt install gpsd
Apoi, încărcați nucleul
sudo modprobe garmin_gps
And then connect the unit. Then check with
dmesg the actual device being
used bu the unit, for example
/dev/ttyUSB0. Now you can launch gpsd
Și, la final, conectați-va la instrumentul de urmărire în direct din QGIS.
Folosirea GPSD (în Linux) sau GPSGate (în Windows) se face fâră efort.
The live tracking works both with GPSD
or without it, by connecting the QGIS live tracking tool directly to the
device (for example
The live tracking works both with GPSD
or without it, by connecting the QGIS live tracking tool directly to the device