coordinates.model.ts

export class Coordinates {
    latitude: string | number;
    longitude: string | number;
    accuracy?: number;

    constructor(that?: Coordinates) {
        if (that) {
            this.latitude = +that.latitude;
            this.longitude = +that.longitude;
            this.accuracy = +that.accuracy;
        }
    }
}

geolocation.service.ts

import {Injectable} from '@angular/core';
import {Observable} from 'rxjs/Observable';
import {Coordinates} from './models/coordinates.model';

const GEOLOCATION_ERRORS = [
    'Browser does not support location services',
    'You have rejected access to your location',
    'Unable to determine your location',
    'Service timeout has been reached'
];

@Injectable()
export class GeolocationService {

    public getLocation(): Observable<Coordinates> {
        return Observable.create(observer => {
            if (window.navigator && window.navigator.geolocation) {
                window.navigator.geolocation.getCurrentPosition(
                    (position) => {
                        observer.next(new Coordinates({
                            latitude: position.coords.latitude.toString(),
                            longitude: position.coords.longitude.toString(),
                            accuracy: position.coords.accuracy
                        }));
                        observer.complete();
                    },
                    (error) => observer.error(GEOLOCATION_ERRORS[+error.code]));
            } else {
                observer.error(GEOLOCATION_ERRORS[0]);
            }
        });


    }

}