iOS：跟踪用户正在后台驾驶

Question

我的目标是知道用户何时旅行，即使该应用被杀或在后台。所以我实现了这个：

let locationManager = CLLocationManager()

private func setupLocationManager(){

        locationManager.delegate = self
        locationManager.requestAlwaysAuthorization()
        locationManager.desiredAccuracy = kCLLocationAccuracyNearestTenMeters
        locationManager.distanceFilter = kCLLocationAccuracyNearestTenMeters
        locationManager.allowsBackgroundLocationUpdates = true
        locationManager.activityType = .otherNavigation
    }

func startSignificantChangeLocationUpdates() {

        guard CLLocationManager.significantLocationChangeMonitoringAvailable() else {
            logger.error("significantLocationChangeMonitoringAvailable returned false")
            return
        }

        setupLocationManager()
        locationManager.startMonitoringSignificantLocationChanges()
    }

 func locationManager(_ manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) {

        // only save data above magical 5m/s => 18km/h
        var  filteredLocations = locations.filter{$0.speed > 5}

        //only save the fastest item if multiple data is delived
        filteredLocations = filteredLocations.sorted { (l1, l2) -> Bool in
            l1.speed > l2.speed
        }
        if let fastestLocation = filteredLocations.first{
            if (filteredLocations.count > 0){
                //save to DB
                locationModel.addLocations(clLocations: [fastestLocation])
            }
        }
    }

我的问题是这不是很准确。即使我乘坐火车10分钟内行驶超过10公里，我也只得到2或3个数据点，说我只走了2分钟。

我该如何改进？ kCLLocationAccuracyNearestTenMeters正在消耗大量精力。如果我与Moves比较，那么数据非常准确。但是，当我尝试保护用户隐私时，我不想整合他们的SDK。