Implementing IP-Based Location Positioning in QGIS

Preface: This article is compiled based on the author's experience with internet mapping services. While consumer map applications offer automatic location detection, professional GIS tools like QGIS lack this functionality natively. This guide demonstrates how to implement this feature.

Implementation Principle

Device positioning typically follows two technical approaches:

Using GPS hardware to obtain latitude/longitude coordinates
IP-based geolocation

This article focuses on IP-based positioning. For background on IP geolocation methods, refer to these resources:

QGIS Python API Implementation

The implementation involves three key steps:

Retrieve the user's public IP address
Obtain geographic coordinates associated with the IP
Display the location on the map and adjust the view

Implementation code:

from qgis.PyQt.QtWidgets import QMessageBox
from qgis.core import QgsProject, QgsVectorLayer, QgsFeature, QgsGeometry, QgsPointXY
import requests

def locate_by_ip():
    try:
        # Get current IP address
        ip_response = requests.get('https://api.ipify.org?format=json', timeout=5)
        ip_address = ip_response.json()['ip']

        # Get geographic coordinates from IP
        geo_response = requests.get(f'http://ip-api.com/json/{ip_address}')
        geo_data = geo_response.json()

        if geo_data['status'] == 'success':
            lat = geo_data['lat']
            lon = geo_data['lon']
            city = geo_data['city']
            country = geo_data['country']

            # Create temporary layer
            layer_name = f"IP_Location_{ip_address}"
            layer = QgsVectorLayer("Point?crs=EPSG:4326", layer_name, "memory")
            provider = layer.dataProvider()

            # Create point feature
            feature = QgsFeature()
            feature.setGeometry(QgsGeometry.fromPointXY(QgsPointXY(lon, lat)))
            provider.addFeature(feature)

            # Add to map
            QgsProject.instance().addMapLayer(layer)

            # Center map view
            canvas = iface.mapCanvas()
            canvas.setCenter(QgsPointXY(lon, lat))
            canvas.zoomScale(100000)  # Appropriate zoom level

            # Display information
            QMessageBox.information(iface.mainWindow(), "Location Positioning", 
                                   f"IP Address: {ip_address}\n"
                                   f"Location: {city}, {country}\n"
                                   f"Coordinates: {lat:.4f}, {lon:.4f}")
        else:
            QMessageBox.warning(iface.mainWindow(), "Error", "Failed to retrieve location data")

    except Exception as e:
        QMessageBox.critical(iface.mainWindow(), "Error", f"Operation failed: {str(e)}")

# Execute function
locate_by_ip()

Usage Instructions

Open QGIS Python Console
Create new editor window
Paste the provided code
Execute the script

Result demonstration:

Conclusion

The current implementation demonstrates basic IP-based positioning functionality. Note that the test result shows a location in the USA due to limitations in freely available IP geolocation APIs for Chinese regions. Future enhancements will include:

1.Integration with domestic IP geolocation services
2.Implementation of GPS-based positioning solutions
3.Accuracy improvements for regional positioning

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