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# isRelativeAltitudeAvailable()

Returns a Boolean value indicating whether the current device supports generating data for relative altitude changes.

```
class func isRelativeAltitudeAvailable() -> Bool
```

## Return Value

<doc://com.apple.documentation/documentation/Swift/true> if the device supports relative altitude changes or <doc://com.apple.documentation/documentation/Swift/false> if it does not.

## Discussion

Use this method to determine if altitude updates are available before calling the [`startRelativeAltitudeUpdates(to:withHandler:)`](/documentation/CoreMotion/CMAltimeter/startRelativeAltitudeUpdates(to:withHandler:)) method.

---

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