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# startAbsoluteAltitudeUpdates(to:withHandler:)

Starts the delivery of absolute altitude data to the specified handler.

```
func startAbsoluteAltitudeUpdates(to queue: OperationQueue, withHandler handler: @escaping CMAbsoluteAltitudeHandler)
```

## Parameters

`queue`

The operation queue on which to execute your handler block. The altimeter object stores a strong reference to this object. This parameter must not be `nil`.

`handler`

The handler block to execute when new altitude data is available. This parameter must not be `nil`. For information about the format of this block, see [`CMAbsoluteAltitudeHandler`](/documentation/CoreMotion/CMAbsoluteAltitudeHandler).

## Discussion

Call [`isAbsoluteAltitudeAvailable()`](/documentation/CoreMotion/CMAltimeter/isAbsoluteAltitudeAvailable()) to verify that the current device supports absolute altitude updates before calling the `startAbsoluteAltitudeUpdates(to:withHandler:)` method.

> Note:
> Absolute altitude is only available on iPhone 12 and later and Apple Watch 6 or SE and later.

---

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