---
title: NIDLTDOAMeasurement
framework: nearbyinteraction
role: symbol
role_heading: Class
path: nearbyinteraction/nidltdoameasurement
---

# NIDLTDOAMeasurement

Information from a Downlink Time-Difference-of-Arrival anchor that you use to derive a range estimate.

## Declaration

```swift
class NIDLTDOAMeasurement
```

## Overview

Overview Your app runs on a receiver device that fields messages from nearby physical base stations, or anchors. The framework processes the messages into instances of this class and provides them to your app through the  session(_:didUpdateDLTDOA:) callback. Your app analyzes the measurements to calculate the receiver’s position relative to the anchors in the tracked area. Only sessions that run a NIDLTDOAConfiguration receive Downlink Time-Difference-of-Arrival measurements.

## Topics

### Identifying the anchor

- [address](nearbyinteraction/nidltdoameasurement/address.md)
- [clusterInitiatorAddress](nearbyinteraction/nidltdoameasurement/clusterinitiatoraddress.md)

### Locating the anchor

- [coordinates](nearbyinteraction/nidltdoameasurement/coordinates.md)
- [coordinatesType](nearbyinteraction/nidltdoameasurement/coordinatestype.md)
- [signalStrength](nearbyinteraction/nidltdoameasurement/signalstrength.md)
- [floorElevation](nearbyinteraction/nidltdoameasurement/floorelevation-swift.property.md)
- [NIDLTDOAMeasurement.FloorElevation](nearbyinteraction/nidltdoameasurement/floorelevation-swift.class.md)

### Assessing time difference

- [receiveTime](nearbyinteraction/nidltdoameasurement/receivetime.md)
- [transmitTime](nearbyinteraction/nidltdoameasurement/transmittime.md)

### Evaluating the message

- [measurementType](nearbyinteraction/nidltdoameasurement/measurementtype.md)
- [carrierFrequencyOffset](nearbyinteraction/nidltdoameasurement/carrierfrequencyoffset.md)
- [responderClockFrequencyOffset](nearbyinteraction/nidltdoameasurement/responderclockfrequencyoffset-8wu5r.md)

### Creating a measurement

- [init(coder:)](nearbyinteraction/nidltdoameasurement/init(coder:).md)

## Relationships

### Inherits From

- [NSObject](objectivec/nsobject-swift.class.md)

### Conforms To

- [CVarArg](swift/cvararg.md)
- [CustomDebugStringConvertible](swift/customdebugstringconvertible.md)
- [CustomStringConvertible](swift/customstringconvertible.md)
- [Equatable](swift/equatable.md)
- [Hashable](swift/hashable.md)
- [NSCoding](foundation/nscoding.md)
- [NSCopying](foundation/nscopying.md)
- [NSObjectProtocol](objectivec/nsobjectprotocol.md)
- [NSSecureCoding](foundation/nssecurecoding.md)
- [Sendable](swift/sendable.md)
- [SendableMetatype](swift/sendablemetatype.md)

## See Also

### Measurements

- [NIDLTDOACoordinatesType](nearbyinteraction/nidltdoacoordinatestype.md)
- [NIDLTDOAMeasurementType](nearbyinteraction/nidltdoameasurementtype.md)