<!--
{
  "availability" : [
    "iOS: 14.0.0 -",
    "iPadOS: 14.0.0 -"
  ],
  "documentType" : "symbol",
  "framework" : "ARKit",
  "identifier" : "/documentation/ARKit/ARGeoAnchor/altitudeSource-swift.property",
  "metadataVersion" : "0.1.0",
  "role" : "Instance Property",
  "symbol" : {
    "kind" : "Instance Property",
    "modules" : [
      "ARKit"
    ],
    "preciseIdentifier" : "c:objc(cs)ARGeoAnchor(py)altitudeSource"
  },
  "title" : "altitudeSource"
}
-->

# altitudeSource

A record of the source from which an altitude came.

```
var altitudeSource: ARGeoAnchor.AltitudeSource { get }
```

## Discussion

The value of this property is [`ARGeoAnchor.AltitudeSource.userDefined`](/documentation/ARKit/ARGeoAnchor/AltitudeSource-swift.enum/userDefined) if you set the altitude yourself (see [`getGeoLocation(forPoint:completionHandler:)`](/documentation/ARKit/ARSession/getGeoLocation(forPoint:completionHandler:))).

If your app doesn’t set the altitude, ARKit populates this property to indicate the altitude’s expected accuracy (either [`ARGeoAnchor.AltitudeSource.precise`](/documentation/ARKit/ARGeoAnchor/AltitudeSource-swift.enum/precise), or [`ARGeoAnchor.AltitudeSource.coarse`](/documentation/ARKit/ARGeoAnchor/AltitudeSource-swift.enum/coarse)), depending on the level of confidence ARKit has with the altitude data that’s available at the time.

---

Copyright &copy; 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)