Q: Why do many M-Lab measurements show identical latitude/longitude coordinates? Can I get more precise location data for fine-grained spatial analysis?
A: M-Lab’s geolocation data has intentional limitations due to privacy considerations and the inherent constraints of IP-based geolocation:
Geolocation Source and Privacy
- M-Lab uses MaxMind’s GeoLite2 database for IP geolocation
- Geographic precision is intentionally kept coarse (typically city-level) for privacy protection
- All M-Lab data is publicly accessible, so fine-grained location data could compromise user privacy
Common Limitations
- Multiple measurements may share identical coordinates within a city
- Geolocation accuracy varies significantly by region and ISP
- Rural or less-populated areas often have very broad location estimates
- The
client.Geo.AccuracyRadiusKmfield indicates the estimated accuracy radius
Improving Spatial Precision
- Filter by accuracy: Use
client.Geo.AccuracyRadiusKm <= 5to focus on more precise estimates - Alternative geolocation services: Consider using paid services like MaxMind GeoIP2, IPinfo, or similar to re-annotate M-Lab data with your own geolocation
- Grid-based analysis: Aggregate data into geographic grids rather than relying on exact coordinates
- Use newer datasets: The
ndt7_uniontable includes measurements from more servers and may provide better geographic coverage
For Fine-Grained Analysis
M-Lab’s built-in geolocation may not be suitable for block-level or infrastructure-specific analysis. Consider combining M-Lab data with external geolocation services or using statistical methods to estimate coverage areas based on network topology and known infrastructure locations.