Mobile location-based apps. University of Tartu Jaak Laineste, Oct. 2015

Transcription

1 Mobile location-based apps University of Tartu Jaak Laineste, Oct. 2015

2 Location-based service overview Part 1

3 Jaak Laineste GIS/LBS experience 18 years in GIS/mapping, 14 years in LBS Regio/Reach-U, Mobile operator LBS in all over the world Nutiteq since 2006 Nutiteq and mobile development Nutiteq Maps SDK key product Part of Mobi Solutions Android and iphone teams: Mobi Labs J2ME and Blackberry past Naval navigation apps

4 Location-Based Services 1. Location-based: 80% of data 2. Service (or mobile application) 3. Mobile technologies (phones, networks) 4. Mobile positioning LBS is a technology, not application type, or business Can be aspect of any application type

5 Android app with map Part 2

6 What can be done (easily) Display map MapView API interactive map: Google Maps, 2D, online Add clickable points to map (annotations, clusters) Add overlays (rasters) Show user GPS location Geocoding android.location.geocoder API, online Reverse-geocoding android.location.geocoder getfromlocation() Find nearest neighbour(s) Find objects in radius (buffer) Depends on data source Calculate distance between objects Location.distanceTo() method Find Point in area (and other georelations) Spatial-enabled GIS engine: PostGIS in server or Spatialite in phone Routing find optimal path in graph Google online API, other on-line routing engines Spatialite routing, in small area Graphhopper offline open source Navigation Turn by turn Telenav SDK

7 Practical coding on Android 1. Adding MapView to app 2. Add layers and objects to map Make pin clickable 3. Manipulate with map view 4. Get and show user location 5. Using geo back-end service CartoDB service Speed camera app

8 If you get stuck Code snippets Guides: Working sample

9 Add Maps SDK to your project 1. Create new project, with single view Domain: nutiteq.ut.ee - important! Minimum SDK : 15, Phone and Tablet Blank activity 2. Copy nutibright-v2.zip to project Assets (no other downloads needed!) 3. Automatic Nutiteq SDK dependency to project build.gradle, add to existing lines buildscript { dependencies { classpath 'com.nabilhachicha:android-native-dependencies:0.1.3' } } apply plugin: 'android-native-dependencies' native_dependencies { artifact 'com.nutiteq:nutiteq_maps_sdk:3.2.0' } dependencies { compile 'com.nutiteq:nutiteq-sdk:3.2.0' } 4. Sync gradle

10 Add MapView to Layout Make sure your AndroidManifest.xml defines INTERNET permission Add com.nutiteq.ui.mapview to your Layout, fullscreen: <LinearLayout xmlns:android=" android:layout_width="fill_parent" android:layout_height="fill_parent" android:orientation="vertical" > <com.nutiteq.ui.mapview android:layout_width="fill_parent" android:layout_height="fill_parent" /> </LinearLayout>

11 Initial code into public void oncreate(bundle savedinstancestate) { super.oncreate(savedinstancestate); setcontentview(r.layout.main); // 1. The initial step: register your license. This must be done before using MapView! MapView.registerLicense("YOUR_LICENSE_KEY", getapplicationcontext()); // Create map view MapView mapview = (MapView) this.findviewbyid(r.id.mapview); // Create base layer. Use vector style from assets VectorTileLayer baselayer = new NutiteqOnlineVectorTileLayer("nutibright-v2.zip"); } // Add layer to map mapview.getlayers().add(baselayer);

12 Data models Raster Vector PNG for maps, lossless JPG for aerials GeoTIFF, coverages Key parameters: bitmap resolution, size, channels Base objects: points, lines, polygons Collections: multi-polygon, multi-line, multi-point Attributes (fields): text/boolean/numeric/binary etc Texts on map - labels from attributes Layer same as table in DB Special cases: topological models, graphs, 3D vectors

13 GIS Layers

14 Other data models Elevation models DEM Digital Elevation Model TIN - triangulated irregular network 3D worlds Collada, X3D, KMZ CityGML, IndoorGML Point clouds Lidar laser measurements

15 Hillshade from DEM

16 TIN

17 Point cloud

18 3D model

19 GIS layers in a map One base layer Background map: Google, OpenStreetMap etc Raster-based Overlay layer(s) Points of Interest, markers GPS location dynamic info Lines, Polygons Clustered points

20 Add pin to map // Initialize a local vector data source Projection proj = mapview.getoptions().getbaseprojection(); LocalVectorDataSource vectordatasource1 = new LocalVectorDataSource(proj); // Create marker style MarkerStyleBuilder markerstylebuilder = new MarkerStyleBuilder(); markerstylebuilder.setsize(30); MarkerStyle sharedmarkerstyle = markerstylebuilder.buildstyle(); // Add marker to the local data source MapPos mappos = proj.fromwgs84(new MapPos( , )); Marker marker1 = new Marker(mapPos, sharedmarkerstyle); vectordatasource1.add(marker1); // Create a vector layer with the previously created data source VectorLayer vectorlayer1 = new VectorLayer(vectorDataSource1); // Add the previous vector layer to the map mapview.getlayers().add(vectorlayer1);

21 Make map pin interactive 1. Add metadata to object marker1.setmetadataelement("id","my PIN"); 2. Add Listener

22 Projections

23 Coordinate systems Geographical spherical Units: Latitude and Longitude Based on an ellipsoid, e.g. WGS-84 Datums, also WGS84 for GPS DMS for display, decimal degrees for programming Projected - cartesian Units: usually meters (can be km, miles) Hundreds of named projections, mostly for local regions Reduce distortions: keep angles, distances, areas equal

24 Geographical coordinate space

25 Cartesian (projected) coordinate space

26 Different projections Extreme examples In real life Plate Carre, Latitude/Longitude, WGS84 (EPSG:4326) Web map Spherical Mercator (EPSG:3857) Mercator UTM with zones Robinson equal-area world map Lambert Conformal Conic, L-EST (EPSG:3301)

27 Robinson

28 Mercator

29 Short and long projection description <EPSG:3301> EPSG codes: 4-5 digit numbers EPSG:4326 WGS84 EPSG:3301 Estonian system EPSG:3857 Google web Mercator A.k.a EPSG: PROJCS["Estonian Coordinate System of 1997", GEOGCS["EST97", DATUM["Estonia_1997", SPHEROID["GRS 1980", , , AUTHORITY["EPSG","7019"]], TOWGS84[0,0,0,0,0,0,0], AUTHORITY["EPSG","6180"]], PRIMEM["Greenwich",0, AUTHORITY["EPSG","8901"]], UNIT["degree", , AUTHORITY["EPSG","9122"]], AUTHORITY["EPSG","4180"]], UNIT["metre",1, AUTHORITY["EPSG","9001"]], PROJECTION["Lambert_Conformal_Conic_2SP"], PARAMETER["standard_parallel_1", ], PARAMETER["standard_parallel_2",58], PARAMETER["latitude_of_origin", ], PARAMETER["central_meridian",24], PARAMETER["false_easting",500000], PARAMETER["false_northing", ], AUTHORITY["EPSG","3301"], AXIS["Y",EAST], AXIS["X",NORTH]]

30 View manipulation and some Options // Set view mapview.setfocuspos(proj.fromwgs84(new MapPos( , )), 0); mapview.setzoom(10, 0); // zoom 2, duration 0 seconds (no animation) mapview.setmaprotation(0, 0); mapview.settilt(90, 0); // Some options mapview.getoptions().setrotatable(false); // make map not rotatable mapview.getoptions().settilethreadpoolsize(4); // faster tile downloading mapview.getoptions().setzoomrange(new MapRange(8, 20)); // Use MapView coordinate system like this: mapview.getoptions().setpanbounds(new MapBounds(new MapPos( , ), new MapPos( , )));

31 Web map tiling system (OSM) zoom = 0 zoom = 1 zoom = 2 y X=0 Y=0 X=0 Y=0 X=1 Y=0 X=0 Y=0 X=1 Y=0 X=2 Y=0 X=3 Y=0 X=0 Y=1 X=1 Y=1 X=0 Y=1 X=1 Y=1 X=2 Y=1 X=3 Y=1 X=0 Y=2 X=1 Y=2 X=2 Y=2 X=3 Y=2 X= Y=78432 Zoom=18 X=0 Y=3 X=1 Y=3 X=2 Y=3 X=3 Y=3 x

32 User location on map Android Location API GPS+network+cell Alternative positioning methods External GPS (BlueTooth) Mobile Positioning Indoor positioning

33 Location API in Android Location Provider Selected automatically based on set requirements: Cell-id,WiFI or GPS Features Listen for updates most common Last known location (cached) not suggested Proximity alerts not guaranteed Best strategy depends on app

34 Using Android location API code 1. Define permission in AndroidManifest.xml <uses-permission android:name="android.permission.access_fine_location"/> 2. Add a Polygon (circle) to map Can reuse Layer+DataSource of pins 3. Define LocationListener Get location updates, always async Get provider status updates 4. Define LocationManager with location Criteria Time and accuracy criteria Do not consume too much power

35 Add a circle to map // style for GPS My Location circle PolygonStyleBuilder polygonstylebuilder = new PolygonStyleBuilder(); polygonstylebuilder.setcolor(new Color(0xAAFF0000)); PolygonStyle gpsstyle = polygonstylebuilder.buildstyle(); MapPosVector gpscircleposes = new MapPosVector(); final Polygon locationcircle= new Polygon(gpsCirclePoses, gpsstyle); // initially empty and invisible locationcircle.setvisible(false); vectordatasource.add(locationcircle);

36 Define locationlistener final LocationListener locationlistener = new LocationListener(){ public void onlocationchanged(location location) { Log.debug("GPS onlocationchanged "+location); if (locationcircle!= null) { locationcircle.setposes(createlocationcircle(location, proj)); locationcircle.setvisible(true); mapview.setfocuspos(proj.fromwgs84( new MapPos(location.getLongitude(), location.getlatitude())), 0.5f); } public void onstatuschanged(string s, int i, Bundle bundle) public void onproviderenabled(string s) public void onproviderdisabled(string s) {}

37 Define LocationManager LocationManager locationmanager = (LocationManager) getsystemservice(context.location_service); // user has maybe disabled location services / GPS if(locationmanager.getproviders(true).size() == 0){ Toast.makeText(this, "Cannot get location, no location providers enabled. Check device settings",toast.length_long).show(); } // use all enabled device providers with same parameters for(string provider : locationmanager.getproviders(true)){ Log.debug("adding location provider " + provider); locationmanager.requestlocationupdates(provider, 1000, 50, locationlistener); }

38 Create circular polygon private MapPosVector createlocationcircle(location location, Projection proj) { // number of points of circle int N = 50; int EARTH_RADIUS = ; float radius = location.getaccuracy(); double centerlat = location.getlatitude(); double centerlon = location.getlongitude(); } MapPosVector points = new MapPosVector(); for (int i = 0; i <= N; i++) { double angle = Math.PI*2*i/N; double dx = radius*math.cos(angle); double dy = radius*math.sin(angle); double lat = centerlat + (180/Math.PI) * (dy/ EARTH_RADIUS); double lon = centerlon + (180/Math.PI) * (dx/ EARTH_RADIUS)/Math.cos(centerLat * Math.PI/180); points.add(proj.fromwgs84(new MapPos(lon, lat))); } return points;

39 Indoor LBS 90% time people are indoors Retail, Safety Indoor maps Google Maps, Tango HERE: 90K buildings, 71 countries in 2014 Micello (15K), aisle411 (12K) 3D technologies R&D Tartu: Wayfinder Sanborn SPIN: Indoor Positioning IndoorAtlas, Pole Star etc Technologies ibeacon positioning BT LE Standards: IndoorGML, OSM Simple 3D, i-locate.eu

40 Map data sources Adding online (or offline) data to map

41 Common GIS file formats Shapefile (ESRI) most common 4+ files per layer:.shp,.dbf etc One geometry type per layer allowed No style information, pure geometry Optional: projection file.prj, spatial index, charset KML (Google, open standard) Vector data, includes styles Special data types: 3D data (Collada), linked data, visual coverages Can have only WGS84 coordinates Can be KMZ zipped file Other formats SpatiaLite: vector and raster data. Any projection, no styles. GeoJSON and TopoJSON web/javascript-friendly Text files (CSV) with coordinates or addresses Every commercial GIS has own format(s) Free converter:

42 Spatial SQL database basics Special column data types(s): Geometry, Point, Polygon... Geographical indexing Usually R-Tree, based on object bounds Geographical functions: Manipulations, relations, queries etc Metadata table: Defines coordinate system, data type for every Geometry column

43 Geometry primitives in WKT (2D)

44 Multipart geometries in WKT (2D)

45 PostGIS sample: spatial query Be careful with : Coordinate systems distances in meters vs degrees Big data: use two-phase filters for spatial indexes

46 PostGIS : spatial query

47 OpenStreetmap As key data source

48 OpenStreetMap (OSM) Free and open data Vector data in 2D Streets, roads, buildings, amenities etc A lot of services Map images (tiles), geocoders, routers etc Special views: opencyclemap, openpistemap etc Everyone can improve the map in Estonian

49 ID web-based OSM editor

50 JOSM OSM main editor

51

52 OSM advantages Free and open to use No advertising, restrictions Vector data access Custom styles for mapping Own filters of data on map (layers) Interactive data overlays (POI layers) Advanced services: routing, search, analysis,... Fast and easy updates Find error go fix it yourself! Note: follow community guidelines

53 Commercial map data Global vendors Vector: HERE, TeleAtlas (TomTom), AND Aerial/Satellite: DigitalGlobe, Planet Labs Local vendors Estonia: Regio, Maa-amet In almost every country, quite detailed Specifics Technically quite flexible Usually quite expensive

54 CartoDB in mobile app

55 CartoDB intro Cloud-based geo data storage Like google drive, dropbox etc, but with geo Spatial data view Map visualizations (thematic maps) Edit geometries on map Developer API RESTful SQL API Map tile API raster map JS SDK for web, can be used with Google Maps API

56 Demo data for your app Estonian speed cameras from poiplaza.com Estonian villages and counties (külad ja maakonnad) About 1M OpenStreetMap amenities from Europe Datasets and Maps Table and Map views Thematic map for speed cameras Joined dataset for speed cameras and admin borders

57 Load and show speed cameras CartoDB SQL API <API CALL> link under dataset Combine data from several tables: SELECT sc.*, ay.animi, ay.mnimi, ay.onimi FROM ee_speedcams sc, asustusyksus_ ay WHERE st_contains(ay.the_geom,sc.the_geom)

58 Use GeoJSON geometry format Default API geometry: in WKB + HEX encoding Quite simple binary, but needs parsing GeoJSON format The common web geo format Add parameter &format=geojson to API URL Parse result in app code Use general Android JSON parser for Collection GeoJSON parser from Nutiteq SDK for geometry

59 Load GeoJSON, create Markers Use AsyncTask for multi-threading Define parser, set projection GeoJSONGeometryReader geojsonparser = new GeoJSONGeometryReader(); geojsonparser.settargetprojection(new EPSG3857()); Load GeoJSON from GeometryCollection JSONObjectjson = new JSONObject(result); JSONArrayfeatures = json.getjsonarray("features"); for(int i=0;i<features.length();i++) { JSONObject feature = (JSONObject) features.get(i); JSONObject geometry = feature.getjsonobject("geometry"); Geometry ntgeom= geojsonparser.readgeometry(geometry.tostring()); JSONObject properties = feature.getjsonobject("properties"); Marker popup = new Marker( ntgeom, markerstylebuilder.buildstyle());

60 Useful geo tools

61 Free GIS tools Desktop tools mapping, analysis, processing Quantum GIS (QGIS) Google Earth Pro- view/create KML Trimble SketchUp create 3D models Databases PostGIS Postgres add-on. Spatialite SQLite extension (not enabled on Android/iOS) Processing GDAL/OGR raster and vector library, command-line converters

62 Free GIS tools for developers PostGIS JTS Proj.4 Postgres SQL server extension Raster features Java Topology Suite, ports in C (GEOS) etc Lot of complex algorithms, geometries, graphs, geographical indexes C-based, has few ports. Proj4J for Java Hundreds of predefined projections Web platforms GeoDjango (Python), GeoNode (Node.js), GeoTools (Java)

63 Free GeoWebServices SaaS CartoDB.com Hosted PostGIS servers GISCloud.com Also server-based editing is possible Not very mature OpenStreetMap Only for community-created data Content requirements: verifyable objects etc Github GeoJSON and TopoJSON support geojson.io GeoJSON editor Google Fusion Tables General data table API service Includes basic geo-features

64 Thank you! Jaak Laineste Founder, Nutiteq