Geospatial data and GPS accuracy

Why location data matters

quiXzoom clients — highway authorities, property managers, insurance assessors, and infrastructure operators — use GPS coordinates from your submissions to build and update geospatial asset databases. Every approved photo is stored against a set of coordinates that will be queried, compared against previous surveys, and used to dispatch maintenance teams.

A submission with accurate GPS coordinates adds a verified, georeferenced data point to a client's asset management system. A submission with degraded GPS accuracy creates a location uncertainty that may prevent the record from being associated with the correct asset — resulting in rejection.

GPS quality is not a technicality. It is a core data quality dimension, as important as image sharpness or correct framing.

GPS accuracy levels

Most smartphones report location using one of three accuracy modes. Always use precise mode for quiXzoom missions.

EXIF metadata: what is stored in your photos

Every photo taken on a smartphone contains Exchangeable Image File (EXIF) metadata embedded in the image file. quiXzoom's review system reads this metadata on every submission. The following fields are verified:

• GPS Latitude / LongitudeAsset location coordinates
• GPS AltitudeElevation above sea level
• GPS TimestampPrecise capture time (UTC)
• GPS DOP / AccuracyDilution of precision indicator
• Make / ModelDevice used for capture
• DateTimeOriginalLocal capture timestamp
• FocalLengthOptical zoom detection
• DigitalZoomRatioDigital zoom detection

Do not edit, strip, or post-process submitted photos before upload. Third-party photo editing applications may remove or alter EXIF data, causing automated rejection even if the image quality is acceptable.

Common GPS errors and how to avoid them

• Indoor GPS: GPS satellites cannot penetrate building structures. If you have been indoors, allow 45–90 seconds of open-sky exposure before your first capture. The GPS indicator in the quiXzoom app will show acquisition status.
• Moving while capturing: Taking a photo while walking causes a timestamp-position mismatch as GPS position lags the device's physical movement. Stop, wait 2 seconds, then capture.
• Tunnel exit drift: Exiting a tunnel, underground car park, or covered walkway causes GPS to re-acquire from a stale last-known position. A 60-second open-sky wait resolves this in most cases.
• Urban canyon effect: In dense city centres with tall buildings on both sides, GPS multipath errors reduce accuracy to 5–15 m. Position yourself at a road junction or open area to achieve better sky view before capturing.
• Location services disabled: The quiXzoom app requires location services to be enabled at all times during a mission. Disabling location mid-mission causes submissions to be stored without GPS data and automatically rejected.

How to verify GPS status before starting

Before beginning any mission cluster, run through the following check:

• Open device Settings and confirm location mode is set to high accuracy or precise GPS.
• Open a maps application and confirm your displayed position matches your actual location to within one or two metres. If the position shown is more than 10 metres off, wait for re-acquisition.
• In the quiXzoom app, the mission view displays your current GPS accuracy radius. Begin capturing only when the accuracy indicator is below 5 metres.
• If GPS acquisition fails after 90 seconds outdoors, restart the device's location services (toggle off and on) and wait again.

Impact on approval rate

Internal quiXzoom data shows a consistent relationship between GPS accuracy and mission approval outcomes:

• Missions submitted with GPS accuracy below 3 metres have an approval rate 23 percentage points higher than missions submitted with accuracy above 15 metres.
• GPS errors account for approximately 18% of all first-submission rejections across the platform.
• GPS-related rejections are entirely preventable with correct device configuration and pre-mission verification.