iOS - Calculating distance, azimuth, elevation and relative position (Augmented Reality)

Question

I am starting to build an augmented reality app where you can place an image on the screen on your augmented reality camera view and it stays in that position on the Earth,

Answer 1

Swift 3

Gyroscope code update:

import CoreMotion
...
        motionManager.deviceMotionUpdateInterval = 0.1
        motionManager.startDeviceMotionUpdates(to: OperationQueue.current!) { deviceManager, error in
            guard let dm = deviceManager else { return }
            let roll = dm.attitude.roll
            let pitch = dm.attitude.pitch
            let yaw = dm.attitude.yaw

            print("r: \(roll), p: \(pitch), y: \(yaw)")
        }