Openlayers.Layer.OSM
Total Page:16
File Type:pdf, Size:1020Kb
MOBILE LOCATION-BASED APPS Lecture in University of Tartu Jaak Laineste, 13.10.2011 Part 1 LOCATION-BASED SERVICE OVERVIEW Background • GIS/LBS experience 15 years in GIS/mapping, 10 years in LBS Mobile operator LBS in all over the world Nutiteq est. 2006 • Nutiteq and mobile development Part of Mobi Solutions group since 2009 J2ME, Android, BlackBerry, iPhone teams Major customer projects Location-Based Services • Location-based: 80% of data • Service (or mobile application) • Mobile technologies (phones, networks) • Mobile positioning • LBS is a technology, not application type Can be aspect of any application type Two meanings of LBS • Old meaning (200x): Mobile Positioning – MPS User Interface: SMS, web, WAP, USSD, IVR • Today’s LBS : (201x) smartphones with GPS, tablets mobile apps, web services, HTML5 Operator-based LBS • Mobile Positioning Find location using mobile network Works with any mobile, no requirements Accuracy without GPS: 300m ... 30 km (~1 km avg) Can also use in-phone GPS / A-GPS Only operator can do • Typical services FriendFinder, Games Find Nearest Fleet Management • Recent trends Operators open APIs, including location There are aggregators: e.g. LocationLabs, Loc-Aid Popular LBS apps in smartphones • Navigation Tomtom, Navigon, Garmin, Nokia maps etc. Also waze • Business around you reviews, events, classifieds etc Yelp, Loopt, Qype, Zvents, Eventful, Opentable etc • Transit and traffic info where available • Trapster • Social: Facebook checkins • Games: Foursquare Un-successful applications • friend tracking • track my location • location-based advertising • location-based alerts • augmented reality Hard problems • GPS takes too much battery • GPS coverage and accuracy is bad No indoors • Maps are limited No indoors No walking level • Real needs are hard to estimate Successful apps • Local is local • Content is important, and expensive • Understand topic pymwymi • There is no killer app but you can create killer service if you do the execution • Location is just a technology Aspect of an application, often not the core Part 2 GIS INTRODUCTION • Geographic With geographical dimension • Information • System Software, servers, computers • Wikipedia: a system designed to capture, store, manipulate, analyze, manage, and present all types of geographically referenced data. In the simplest terms, GIS is the merging of cartography, statistical analysis, and database technology GIS term „Classic“ GIS • Started in early 1970’ies • Key companies, drivers ESRI, Intergraph, MapInfo, AutoDesk, Oracle Universities: • Key focus Desktop-GIS – special GIS tools Servers, client-server model • Expensive, specialized, heavy • Recent developments (from late 90ies) OGC standards: WMS, WFS, GML etc Neo-geo • Web/Internet-based Cloud services • Free commercial tools Google: Maps, Earth, SketchUp, FusionTables etc Yahoo, Microsoft Bing, MapQuest • Open source software OSGeo.org: server, desktop, web • Open sourced data OpenStreetMap Mobile LBS future • Augmented Reality Issue: mobile sensors Needs powerful image processing • 3D 3D earth (2.5D) Buildings, textures etc • 360-degree view Issue: bandwidth • Walking/local/indoor maps Issue: content update is expensive • Your ideas ! GIS TECHNOLOGY AND DEVELOPMENT Why special approach • Data is quite complex Two-dimensional Can be even 3D Complex relations Nice visualization is processing-hungry • Base maps Big datasets, different features • Specific map data Dynamic, can be big etc "It's a small world, but I wouldn't want to paint it.„ - Steven Wright Data in a single screen Type – 4 bytes Name – 100 bytes Point on map – 16 bytes Base map – 32+ (500+)KB 27 relations 205 ways (lines) 1920 points (x 16 b) Checkins – 4 bytes People – 4 bytes Geo basics • Data models vector raster other • Coordinates Projections, coordinate systems Data models • Raster PNG for maps, lossless JPG for aerials GeoTIFF, coverages Key parameter: resolution, size • Vector Base primitives: points, lines, polygons Compounds: multi-point, multi-line, multi-polygon Attributes - text/boolean/numeric/binary etc Texts on map - labels from attributes Layer – same as „table“ in DB, „class“ in OOP Special vector: topological models, graphs Other data models • Elevation models DEM – Digital Elevation Model TIN - triangulated irregular network • 3D worlds Collada, X3D Google Earth Warehouse • Point clouds Lidar – laser measurements Hillshade from DEM TIN Point cloud GIS Layers GIS layers simplified • 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 Demo • Quantum GIS with vector in action • Open vector data layers • Styling map QGIS with OSM data Typical vector data operations • Mapping Request data for bounding box (BBOX) Reprojection (if needed) Show set of layers Style data – colors, symbols etc Different map zooms have different data • Geocoding – address to coordinates • Reverse-geocoding • Find nearest neighbour(s) • Find objects in radius (buffer) • Calculate distance between objects • Find Point in polygon • Routing – find optimal path in graph • Clustering - show big datasets on map Common GIS Data formats • Shapefile (ESRI) – most common 4-5 files per layer: .shp, .dbf etc One geometry type per layer allowed No style information, pure geometry Optional projection file .prj • 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. Text files with coordinates or addresses Every commercial GIS has own format(s) Free converter: http://www.gdal.org/ogr/ogr_formats.html Spatial SQL database basics • Special column data types(s): Geometry, Point, Polygon ... • Geographical indexing Usually R-Tree, based on object bounds (bbox) • Geographical functions: Manipulations, relations, queries etc etc • Metadata table: Defines coordinate system, data type for every Geometry column Geometry primitives in WKT (2D) Multipart geometries in WKT (2D) PROJECTIONS 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 Geographical coordinate space Cartesian (projected) coordinate space Different projections • The Globe Applet http://www.jhlabs.com/java/maps/proj/ • Check out some Oblique Mercator, Cassini, Rectangular Polyconic • Common in real life Plate Carre, Mercator, Spherical Mercator, UTM, Lambert Conformal Conic (in L-EST) Short and long projection description <EPSG:3301> EPSG codes: PROJCS["Estonian Coordinate System of 1997", GEOGCS["EST97", DATUM["Estonia_1997", • EPSG:4326 – WGS84 SPHEROID["GRS 1980",6378137,298.257222101, AUTHORITY["EPSG","7019"]], • EPSG:3301 – Estonian system TOWGS84[0,0,0,0,0,0,0], • EPSG:3587 – „Google web“ AUTHORITY["EPSG","6180"]], PRIMEM["Greenwich",0, Was also EPSG:900913 AUTHORITY["EPSG","8901"]], UNIT["degree",0.01745329251994328, AUTHORITY["EPSG","9122"]], AUTHORITY["EPSG","4180"]], UNIT["metre",1, AUTHORITY["EPSG","9001"]], PROJECTION["Lambert_Conformal_Conic_2SP"], PARAMETER["standard_parallel_1",59.33333333333334], PARAMETER["standard_parallel_2",58], PARAMETER["latitude_of_origin",57.51755393055556], PARAMETER["central_meridian",24], PARAMETER["false_easting",500000], PARAMETER["false_northing",6375000], AUTHORITY["EPSG","3301"], AXIS["Y",EAST], AXIS["X",NORTH]] Coordinates as QR-Code • http://zxing.appspot.com/generator/ „GEO:26.7144,58.3784“ MAP DATA SOURCES Web maps • Google Maps Javascript, Flash, Static APIs, Earth 3D Geocoding and Directions (routing) services Mobile APIs: Android, iPhone • Bing Maps Web, Mobile API (WP7, iPhone) • Nokia Ovi Maps Web, Mobile (Qt, J2ME) Web map restrictions • Technical restrictions Cannot be restyled, no visual customization Limited to provided API-s, feature limits Can’t get map data, or even images Some mobile platforms not served at all • Commercial limits Some services (e.g. Navigation) require special license Advertising is added Commercial map data • Global vendors Vector: Navteq (Nokia), TeleAtlas (TomTom), AND Aerial/Satellite: DigitalGlobe, Blom ASA ... • Local vendors Regio, Maa-amet In almost every country, more detailed to globals • Specifics Technically quite flexible Usually quite expensive 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 www.openstreetmap.org www.maakaart.ee – in Estonian Potlatch2 – web-based OSM editor JOSM – OSM main editor 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 GIS TOOLS Main OGC standards • WMS – Web Mapping Service Send coordinates in URL, get map image • WFS – Web Feature Service Send coordinates in URL, get vector data as GML WFS-T – enables writing to server • GML – Geography Markup Language XML-based