Development of a Mobile Campus Information System

Transcription

1 Master Thesis Run SHI Run SHI Development of a Mobile Campus Information System Duration of the Thesis: 6 months Completion: June, 2013 Supervisor: Dr.-Ing. Volker Walter Examiner: Dr.-Ing. Volker Walter Background Smartphones are highly integrated devices with basic mobile functions, high-speed Internet surfing, photo taking, media playing and many more. The wide selection of third-party applications enriches the functions of smartphones. Most location-based applications apply GPS to acquire location data and the location information is used for navigation, finding POI (Place of Interest) and geocoding. To develop a location-based application, different APIs (Application Programming Interface) are available, such as Google Maps API, ArcGIS Runtime SDK, Microsoft Bing Map SDK and OSMDroid. Among these, the first two APIs are mostly used because they have the most searching results in Google Search. It is very interesting to understand how to develop a location-based application on mobile phones and to evaluate developing experience of different APIs. Objective Owing to the fact that Android is open source and has the biggest market share (Gartner 2013), it is chosen as the operating system for developing mobile applications. Moreover, some of the existing APIs for programmers to develop a LBS application are: Google Maps API, ArcGIS Runtime SDK, Microsoft Bing Map SDK and OSMDroid. Since the first two APIs are the mostly used, they are adopted to develop the application. In addition, the LBS application is a campus information system which assists users, especially new students, to get familiar with the campus site Stadtmitte, Univeristy Stuttgart, Germany. In summary, the objective of the thesis is to develop a campus information system on Android with both Google Maps API and ArcGIS Runtime SDK and a comparison is made from the perspective of both functionality and developing experience.

2 Implementation This campus information system is developed for Android phones to present Campus Stadtmitte of University Stuttgart. It has functions of positioning, routing, showing GPS information and important building information. Developed in Java language, the application is implemented by two different Application Programming Interfaces (APIs), Google Maps API for Android and ArcGIS Runtime SDK for Android, in order to compare their pros and cons. Development environment: Operating System: Windows 7 Ultimate, 64-bit IDE: Eclipse Helios and Android SDK API: Google Maps API for Android v2 ArcGIS Runtime SDK for Android v Displaying the Map To display a map, Google Maps API requires a key while ArcGIS Runtime SDK does not. At the same time, ArcGIS Runtime SDK has a wider selection of map resources. Developers can use not only online maps (ArcGIS online, ArcGIS server), but ArcGIS portal of users as well. That is to say, the developer can use maps he created in ArcGIS Desktop in Android application, which helps the application have a clearer aim. For instance, if an application is aimed for people to find the nearest health care facility such as hospitals, pharmacies, or clinics, a thematic map emphasizing both on road features and health care features is better than common base maps. 2 Positioning Android SDK provide a class named LocationManager to access system location services. It can update periodically the device s geographical location. If the application has the coarse permission only, then GPS services or other passive location services are no longer available. Position can still be acquired, but is updated less frequently with less accuracy. 3 Routing Google Maps API Approach Routing in the Campus Information System applies Google Navigator. The core code to fire up Google Navigator is as follows: Intent intent = new Intent(android.content.Intent.ACTION_VIEW,

3 Uri.parse(" + lat + ">,<" + lon + ">&daddr=<" + lat_k1 + ">,<" + lon_k1 + ">")); startactivity(intent); In the code above, lat and lon are WGS84 coordinates of the user s current location, updated in real-time. Parameters lat_k1 and lon_k1 are coordinates of the destination, in this case, building K1. This code shows the routing from current location to building K1. Figure 1 shows the driving direction of current location to Mensa in campus. Once the direction result is viewed by the user, he can switch back to Campus Information System by pressing back button beneath the phone screen and exiting Google Navigator. Figure 1 Driving direction from current location to Mensa ArcGIS Runtime SDK Approach In the example downloaded from ESRI, starting point of routing is current location of the device and ending point is the location chosen by the user designated by a long press of the screen. Unfortunately, the example does not work on Sony Xepria U or HTC Wildfire. The error message is shown in Figure 2. If run in debug mode, it could be found that both coordinates for starting and ending points are stored in variables. The exception happens with the creating of routing task.

4 Figure 2 Error message of routing 4 Displaying Satellite Information Android SDK provides a public static interface GpsStatusListener to report current state of GPS. The method ongpsstatuschanged (int event) should be called in MainActivity to report changes in GPS status. LocationManager has a getgpsstatus( ) function to acquire GPS status. There are four statuses in total: GPS_EVENT_STARTED: GPS has started. GPS_EVENT_STOPPED: GPS has stopped. GPS_EVENT_FIRST_FIX: GPS has received its first fix. Function gettimetofirstfix() acquires the time to receive first fix from starting. GPS_EVENT_SATELLITE_STATUS: GPS has functioned periodically and function getsatellites( ) can be called to find the status of each satellite. Figure 3 shows the information displayed on the device screen.

5 Figure 3 GPS information 5 Displaying Relevant Information Google Maps API Approach To display information of at certain location when touched, Google Maps API provides two methods: OverlayItem and Markers. In Campus Information System, OverlayItem is adopted considering it is built on MapView structure. Building information is displayed as in Figure 4. Figure 4 Displaying building information ArcGIS Runtime SDK Approach The concept of features and layers are applied in ArcGIS Runtime SDK, as in other

6 products of Esri. In the Campus Information System, each building is created as a feature and added to a new layer. The information necessary for displaying are stored as attributes of the building. Furthermore, ArcGIS Runtime SDK offers the method of callout to display information. Figure 5 is the information window tapped by the user. Figure 5 Building information Conclusion Below is a summary table of comparison. Table 1 comparison between two methods Google Maps API ArcGIS Runtime SDK Functions Map display Requires API key Does not require key Map resource Google Maps Maps from ArcGIS Online, ArcGIS Portal of users, ArcGIS Server Routing Apply Google Not applicable Navigator Information Display Overlay method Feature and layer method Network Analysis No Yes Support Official Tutorial Requires developing Requires developing experience experience Official Example No Yes Online Help Many posts and blogs Very few information Updates 4 updates since Dec updates since Dec 2011

7 In short, ArcGIS Runtime SDK has a more powerful functionality, considering its rich map resource and network analysis service. But the developing experience with Google Maps API is definitely better. As a new and fast developing technology, implementing applications on Android may meet many problems and errors. Therefore, articles and problems discussed by other developers on the Internet contribute a lot to solving problems. From my point of view, Google Maps API is more suitable to develop location based application for daily uses, such as finding the nearest restaurant or supermarket, while ArcGIS Runtime SDK is more appropriate to implement applications for professional GIS people. For instance, GIS people wants to investigate land use in an area and it is necessary for them to go out and record the use of each land polygon. Computers are too big to carry and an application on Android will solve the problem. They can edit the attributes of land polygons, adding or deleting features according to the land in reality, or even do some simple analysis on the phone. In summary, both Google Maps API and ArcGIS Runtime SDK can develop location based applications on Android. The choice to apply which method depends on the aim the application, as well as the consideration of developing experience. Reference (Mari 2013) Marcello Mari. Top global smartphone apps, who s in the top 10. GlobalWebIndex. Aug. 2 nd Available at : (Gartner 2013) Gartner. Gartner Says Asia/Pacific Led Worldwide Mobile Phone Sales to Growth in First Quarter of Gartner Newsroom. May 14 th Available at (FCC 2005) Federal Communication Commission. FCC Amended Report to Congress on the Deployment of E-911 Phase II Services by Tier III Service Providers. April 1 st p1. (Karimi, Hammad 2004) Hassan A. Karimi, Amin Hammad. Telegeoinformatics: location-based computing and services. US. CRC Press (Brewer 2009) Charles W.G. Brewer. How effective can GSM signals, using DCM, be as an aid to coastal navigation. The Plymouth Student Scientist. 2009, 2, (2)