Crowdsourced detection of areas where GPS/GNSS positioning is degraded, unavailable, or potentially affected by interference.

Today, Waze does an excellent job using aggregated phone motion data to detect traffic speed, crashes, road hazards, and other conditions. A similar approach could help detect locations where many devices suddenly experience degraded GPS quality. The user-facing alert could be simple and non-alarming, such as: “GPS signal degraded ahead” or “Navigation accuracy may be reduced in this area.”

This would be useful because when GPS fails or becomes unreliable, users often blame the navigation app. A contextual warning would improve user trust, reduce confusion, and help drivers understand why navigation may temporarily behave poorly. It could also improve safety by reducing the need for drivers to troubleshoot their phones while driving.

The feature could be implemented passively and privacy-preservingly by aggregating GNSS-health indicators across multiple opted-in devices, rather than relying primarily on manual user reports. Useful indicators could include sudden loss of GNSS fix, degraded estimated accuracy, abnormal satellite C/N0 patterns, AGC changes where available, and disagreement between GNSS, inertial, cellular/Wi-Fi, and map-matched motion. The backend could require multiple devices and temporal/geographic consistency before surfacing any alert, which would help distinguish real GNSS degradation from tunnels, urban canyons, bad phone placement, or individual-device problems.

This could start as an internal map-quality signal before becoming a public alert. Even without naming the cause as “jamming,” identifying areas of degraded GPS reliability would help improve routing confidence, map matching, safety messaging, and overall navigation reliability.