(2004). Integrated Mobile GIS and Wireless Internet Map Servers for
Contents
1. n u 7 r ee ee Send Respond eewewewewewewewewewew es es ew es Data synchronization or wireless communication component I l l l l l l enera y ee l l I l l l srry wy KA Server side Components Geospatial data PP GPS Tracklog Map Grid sensetest shp Ejbmxtest EAMTRProad shp GIS Content Server N Figure 1 The architecture of mobile GIS cable based mobile GIS receivers use a stand alone GIS workstation as the content server Wireless based mobile GIS receivers may require advanced web servers or wireless Internet map servers for access ing geospatial data Sometimes one mobile GIS receiver may be used to access multiple web based servers at the same time to integrate multiple GIS layers A single GIS content server can also provide data and services to multiple mobile GIS receivers simultaneously Figure 1 illustrates a very generic mobile GIS architecture Different mobile GIS applications may have unique settings or additional components For example landscape architects may use a remotely sensed image as a background to draw a preliminary design of a tree line without the GPS component Some sensitive data or classified mobile GIS opera tions may become stand alone units without any external communication mechanisms for security reasons The next section introdu2. amp Graphics 25 619 25 digital assistants PDA In Peterson M P ed Maps Sun Microsystems Inc 2003 Java 2D API White Paper http and the Internet Oxford U K Elsevier Science Ltd ava sun com products java media 2 D whitepaper html pp 397 402 Last visited 12 10 2003 Xue Y A P Cracknell and H D Guo 2002 Tsou M H and B P Buttenfield 2002 A dynamic Telegeoprocessing The integration of remote sensing architecture for distributing geographic information geographic information system GIS global position services Transactions in GIS 6 4 355 81 ing system GPS and telecommunication International Tsou M H 2004 Integrating web based GIS and on line Journal of Remote Sensing 23 9 1851 93 remote sensing facilities for environmental monitoring E and management Journal of Geographical Systems 6 2 155 74 Vol 31 No 3 165
3. software packages and hardware devices Sometimes they are referred to by different names such as field based GIS Pundt and Brinkkotter Runde 2000 location based services LBS OGC 2003a Peng and Tsou 2003 wire less GIS mapping Xue et al 2002 and telecartography Gartner 2003 Actually the differences in these names reflect the compli cated nature of mobile GIS applications and the dra matic progress of related GIS telecommunication technologies The following paragraph provides a clear definition of mobile GIS Major Technologies used for Field based GIS Major Applications for Field based GIS e Hardware Pocket PC WinCE PDA Palm OS Tablet PC Windows based e Software Mobile GIS GPS software ArcPAD MapXtend IntelliWhere Onsite e Programming Tools Java J2SE or J2ME Visual Basic NET compact Framework e Wireless Communication Wi Fi or cellular phone signals e GPS External Blue tooth or cable linked e Environmental monitoring and natural resource management e Ecological geographic research field data collection e Utilities maintenance electric gas and water e Asset management systems parcels lands e Educational travel field trips e Emergency response and hazard management Major Technologies Used for LBS Major Applications for LBS e Hardware 3G or 4G mobile phones smart phones or customized vehicle computers e Software Vendor base
4. based services focus on business oriented location manage ment functions such as navigation street routing finding a specific location or tracking a vehicle Jagoe 2002 OGC 2003b The major differences between the field based GIS and LBS are the data editing capabilities Most field based GIS applica tions need to edit or change the original GIS data or modify their attributes Location based services rarely change original GIS datasets but rather use them as the background or reference maps for navigation or tracking purposes Wireless GIS mapping is a subcategory of mobile GIS technology that focuses on the wireless networking capability of mobile GIS services Table 1 Mobile GIS applications and major technologies Table 1 itemizes the major technologies used or considered in field based GIS and LBS and their major application areas In general the field based GIS technologies emphasize the more comprehen sive GIS functions which require computationally intensive devices and larger display screens such as Pocket and Tablet PCs Most field based GIS software packages are cross platform and independent of hardware devices On the other hand LBS tech nologies focus on creating commercial value from location information Each mobile phone system or vehicle based computer has its own proprietary operating system that is usually very difficult to customize To clarify the basic requirements of a mobile GIS framework the ne
5. coverage for their wireless signals but lack broad bandwidth To solve this problem one possible solution would be to utilize broad bandwidth communication systems such as the High Performance Wireless Research and Education Network HPREN http hpwren ucsd edu to provide long distance wireless networking capa bility in the Wi Fi mode Also the recent develop ment of the IEEE 802 16 standard may become a potential wireless network solution for mobile GIS The IEEE 802 16 standard defines the Wireless Metropolitan Area Network MAN Air Interface for broadband wireless access in large urban areas http grouper ieee org groups 802 16 index html with a scalable solution to extend fiber optic backbones On the software development side the design of new data compression technologies for both vector data and raster imagery via wireless networks may also facilitate the transmission of large datasets for mobile GIS applications in the future The second challenge is in the map display and user interface design of mobile GIS applications Since the screen display of most mobile GIS receivers is significantly smaller than those of desktop computers viewing maps and manipulate GIS layers on their 162 Cartography and Geographic Information Science small screens is rather difficult In addition most mobile GIS receivers do not have screens with high contrast display when viewed in direct sunlight The GIS industry and community wil
6. is mobile and suitable for various types of field data collection analysis and monitoring tasks All mobile devices were equipped with GPS GIS and remotely sensed image display capabilities To demonstrate the feasibility of mobile GIS in field applications the project team created several user scenarios and tested the prototype at a remote field location in the Mission Trail Regional Park in San Diego The next section highlights some major tasks and findings derived during the prototype testing User Scenarios and Prototype Testing The purposes of the prototype testing were to demonstrate the capability of the wireless mobile GIS to evaluate the feasibility of our prototype system and to gather user feedback for future system improvement The criteria used in the pro totype testing were e Proof of concept to ensure the prototype system functions properly without failure e Usability evaluation to evaluate whether the prototype can meet the needs of users and e Field agent review to document end user comments and suggestions for improvement to the prototype design and system architec ture issues The following user scenario was a typical habitat management task which focused on detecting land cover changes based on a real time update of GIS data Test Date January 15 2003 Task Description Mission Trails Region Park MTRP rangers and pri vate sector environmental scientists used the Pocket PC an
7. Integrated Mobile GIS and Wireless Internet Map Servers for Environmental Monitoring and Management Ming Hsiang Tsou ABSTRACT With the progress of mobile GIS technology there is a great potential for adopting wireless communications and Internet mapping services for regional environmental management programs and natural habitat conservation This paper provides an overview of a NASA funded research project that focuses on the development of mobile GIS tools and wireless Internet Map Server IMS services to facilitate environmental monitoring and management tasks By developing and testing wireless web based map image servers mobile GIS applications and global positional systems GPS this research created an integrated software hardware infrastructure for a prototype mobile GIS application The mobile GIS prototype allows multiple resource managers and park rangers to access large size remotely sensed images and GIS layers from a portable web server mounted in a vehicle Users can conduct real time spatial data updates and or submit changes back to the web server over the wireless local area network WLAN This paper discusses in general the major components of mobile GIS their current technological limitations and potential problems during implementation Key research agenda for mobile GIS are identified with suggestions for future research and development KEYWORDS Internet mapping mobile GIS GPS wireless communication Introduction
8. Mobile GIS and Wireless Image Web Services for Environmental Monitoring and Management project supported by NASA s Affiliated Research Center ARC at San Diego State University Funding by the NASA ARC program and match ing funds from NASA REASoN 0118 0209 project are acknowledged and greatly appreciated The author wishes to thank John Kaiser the ARC Program Coordinator and Dr Douglas Stow the ARC program Principal Investigator for their coordination efforts on this project as well as the comments of the anonymous referees and editor REFERENCES Angold P G A M Gurnell and P J Edwards 1996 Locational errors in maps from environmental surveys and their implications for information extraction Journal of Environmental Management 47 341 54 Crisp N 2003 Open location based services Technical brief TB1034A White paper Integraph http www intelliwhere com Last visited 12 16 2003 Derekenaris G J Garofalakis C Makris J Prentzas S Sioutas and A Tsakalidis 2001 Integrating GIS GPS and GSM technologies for the effective management of ambulances Computer Environment and Urban Systems 25 267 78 Ehlers M M Gahler and R Janowsky 2003 Automated analysis of ultra high resolution remote sensing data for biotope type mapping New possibilities and chal lenges ISPRS Journal of Photogrammetry amp Remote Sensing 57 315 26 ESRI Environmental Systems Research Institute 2001 Using Ar
9. Wireless Local Area Networks The first and most substantial task of the project was to establish a wireless local area network for the communications between mobile GIS receiv ers and Internet map servers In the prototype an Internet map server ESRI ArcIMS 4 0 was installed on a notebook computer Toshiba Tecra 8100 equipped with a wireless access port Linksys Wireless Access Point Router The notebook and wireless access port were placed inside a vehicle to obtain electrical power from the cigarette lighter socket for wireless communications Field staff then used Pocket PCs equipped with GPS and wireless PCMIA cards to access remotely sensed imagery and GIS data layers from a large capacity database residing on the notebook web server via wireless communication channels Wi Fi Figure 2 illustrates the architecture of the wireless local area network solution of mobile GIS Several possible technologies can be used for wire less data communication including infrared radio microwave and laser transmissions The most popu lar techniques are infrared and radio signals that can be used to create Wireless Local Area Networks wireless LAN A wireless LAN refers to the use of wireless communication technologies to connect PCs laptops printers and hand held devices to traditional hardwired networks over short distances Jagoe 2002 For devices to communicate with each other through a wireless media a wireless network adapter c
10. a R 2000 Mobile and personal communication systems and services New York New York IEEE Press Peng Z R and M H Tsou 2003 Internet GIS Distributed geographic information services for the Internet and wireless networks New York New York John Wiley and Sons Inc Plewe B 1997 GIS online Information retrieval mapping and the Internet Santa Fe New Mexico OnWord Press Pundt H 2002 Field data collection with mobile GIS Dependencies between semantics and data quality GeoInformatica 6 4 363 80 Pundt H and K Brinkkotter Runde 2000 Visualization of spatial data for field based GIS Computers amp Geosciences 26 51 56 164 Cartography and Geographic Information Science Al Internet Explorer 1 14p http 130 191 118 58 MTRP form _ Go Park Ranger ID 23455 _ Types Invasive Plants O animals Oothers Case v Additio Ska ti S 2 2 lakafen a a A CE FileCommander New Locations Damaged Areas Human Interventions Protected Areas New location of Pampas Grass Next to the Visitor Center Upload GIS data O MKDIR Copy to right 1 4276 a Move to right 6314344 0 1879025 2 1 4276_ Z File Left Right Help f X El Figure 10 Real time data upload function via wireless networks Rakkolainen I and T Vainio 2001 A 3D city info for Wintges T 2003 Geodata communication on personal mobile user Computers
11. any environmental problems and habitat monitoring tasks require near real time field mapping and precise positional information These tasks are time consuming and difficult using traditional field mapping and geographic information systems GIS techniques Angold et al 1996 which are often further limited to desktop computers and hard wired network communications Moreover traditional GIS and remote sensing software pack ages are expensive and they are perceived as complicated by field workers who lack advanced remote sensing and GIS skills or training A pos sible solution is to adopt mobile GIS services that can integrate GIS global positioning systems GPS and remote sensing capabilities for access ing geospatial data sets via mobile devices There are many advantages to using mobile GIS devices for environmental management and habitat monitoring Field workers can easily carry mobile GIS devices to field locations for their data collection and validation tasks With wireless communication capability users can perform real time data updates and exchanges between the centralized map servers Ming Hsiang Tsou Assistant Professor Department of Geography San Diego State University San Diego CA 92182 4493 E mail lt mtsou mail sdsu edu gt and distributed mobile clients Another advantage of a mobile GIS solution is that the GIS framework can be integrated with GPS equipment seamlessly to provide comprehensive geode
12. ard with a transceiver must be installed in each device or computer The transceivers act as access points through which signals are broadcast and received from each other Currently one of the most common wireless LAN infrastructures is the IEEE 802 11 or Wi Fi technology IEEE 802 11 specifies the physical and Media Access Control MAC layers for operation of wire less LANs The 802 11 standard provides for data rates from 11Mb s to 54Mb s Pandya 2000 The term Wi Fi is the global brand name across all Vol 31 No 3 157 markets for any 802 1 1 based wireles LAN product Many computers PDAs and printers have begun to adopt Wi Fi or IEEE 802 11 as their major com munication channels There are three extensions in the 802 11 group technology which were considered for this project e 802 11 a provides up to 54 Mbps transfer rate in the 5 GHz band referred to as Wi Fi5 e 802 11 b is the most popular extension and can provide up to 11 Mbps data transfer rate in the 2 4 GHz band Because of the different radio frequency 802 11b devices are not compatible accessible with 802 1 1a signals and e 80211 g provides up to a 20 Mbps data trans fer rate in the 2 4 GHz band Since the 11g and 11b are using the same radio frequency 802 11g devices are backward compatible with 802 11b signals This research adopted the 802 11b Wi Fi technol ogy to create a wireless LAN for the mobile GIS prototype The wireless ope
13. cIMS User s Manual Redland California ESRI Press ESRI Environmental Systems Research Institute 2002 Using ArcPAD ArdPAD 6 Redlands California ESRI Press Gartner G 2003 Telecartography Maps multimedia and the mobile internet In Peterson M P ed Maps and the Internet Oxford U K Elsevier Science Ltd pp 385 96 Haala N and J Bohm 2003 A multi sensor system for positioning in urban environments ISPRS Journal of Photogrammetry amp Remote Sensing 58 31 42 Intergraph 2002 Mobile resource management White paper Intergraph Mapping and Geospatial Solutions http www intergraph com gis Last visited 12 16 2003 Jagoe A 2002 Mobile location services The definitive guide Upper Saddle River New Jersey Prentice Hall Kolodziej K 2002 Real time field data streaming In URISA 40th Annual Conference Proceeding Chicago Illinois October 26 30 2002 Monmonier M 2003 The Internet cartographic surveil lance and locational privacy In Peterson M P ed Maps and the Internet Oxford U K Elsevier Science Ltd pp 97 113 OGC Open GIS Consortium 2003a OpenGIS location services OpenLS Parts 1 5 Core services version 0 5 0 OGC 03 006r1 Open GIS Consortium Inc Wayland Massachusetts OGC Open GIS Consortium 2003b OpenGIS location services OpenLS Part 6 Navigation services version 0 5 0 OGC 03 007rl Open GIS Consortium Inc Wayland Massachusetts Pandy
14. ces a mobile GIS application for environmental monitoring tasks which employs a local wireless communication network and a network based mapping server Developing Mobile GIS for Environmental Monitoring The goal of this research is to respond to the need for wireless web based analytical tools to process remotely sensed imagery used by field partici pants in natural habitat conservation and land management programs The project focused on the development of a mobile GIS architecture to provide basic operational user friendly remote sensing capabilities to a diverse user community of natural resource managers Multiple resource management agencies organizations and com mercial partners participated in this project including Mission Trail Regional Park at San Diego California the Field Stations Office at San Diego State University SDSU Ed Almanza and Associates and the Nature Conservancy of Orange County California The project team developed a portable wireless web based image server integrated with mobile Pocket PC and GPS receivers and demonstrated real time GIS and remote sensing analysis capabilities in the field Several user scenarios were developed to demonstrate the capability of real time monitoring and the change detection tasks typically required in natural habitat reserves by resource managers The mobile remote sensing and GIS data collection and analysis solution provides a user friendly easy to use int
15. cult to see in bright light Improved screen resolution may improve visibility Conclusion and Suggestions for a Research Agenda The integration of mobile GIS technologies and wireless telecommunications was the key focus of this study which utilized mobile GIS application software global positional systems GPS and wireless networking technologies IEEE 802 11b Wi Fi standard The integrated mobile GIS framework provided natural habitat conservation and land management program resource manag ers with integrated mobile geospatial information services that supported and helped optimize their field based management tasks The utilization of commercial off the shelf COTS mobile GIS soft ware and hardware components help local govern ment agencies to justify and obtain budgets to acquire mobile GIS systems During user scenario testing several challenges to the development of mobile GIS applications were identified The fol lowing discussion summarizes these challenges and their possible future solutions The first challenge to implementing wireless mobile GIS is the short communications range of wireless networks and the requirement for broad bandwidth communications Currently most exist ing wireless LAN technologies are capable of only short distance data transmissions ranging from 100 to 300 meters which is not adequate for most field based mobile GIS tasks On the other hand cellular phone networks have extensive spatial
16. d GPS to perform a field mapping and GIS Vol 31 No 3 159 database updating task in order to locate the presence of new invasive plant infestations This task is rep resentative of habitat management fieldwork The target mobile GIS tasks included e Connecting to the wireless ArcIMS Image server via Wi Fi connections from mobile GIS receivers e Reviewing several change detection images MTRPchange using mobile GIS software ArcPAD e Adding new locations of invasive plants by using GPS and Sle hd S Hl 2 Be O A 2 URL http 130 191 118 58 Which service do you want to connect to A Internet Explorer 4 09p http 130 191 118 58 Bo Figure 3 IP based Internet map server and web sites ISESE SRO TIa C of ArcPad S eo J ArcPad S O 2 amp 2 O Te Oe zim a From gt To To gt From Closed Area Figure 4 The basic GIS function in mobile GIS software e Sending updated GIS layers shapefiles back to the server via mobile FTP software Mobile GIS Solution The major goal of this scenario was to demonstrate the function ality of real time wireless data update and GPS GIS integra tion A MTRP park ranger and a private sector environmental sci entist participated as representa tive field users of a mobile GIS system The research team used ArcPAD to access high resolu tion Airborne Data Acquisiti
17. d systems with mobile coding languages WAP C HTML Web clipping e Programming Tools Java J2ME and NET Compact Framework e Wireless Communication 3G or 4G cellular phones or satellite systems e GPS Built in with mobile phones or vehicles e Web Services Enterprise LBS servers providing client user subscriptions e Directory assistance location based yellow pages nearby stores or commercial services e Vehicle navigation real time traffic report and routing functions e Business transaction services location based transaction verifications purchasing e Address query mapping services e Geo tracking services package delivery bus schedules monitoring and explains the differences between the terminologies used in different mobile GIS applications This paper defines the term mobile GIS as an inte vehicle locations e Emergency response 911 calls e Real estate management e Social interaction services looking for friends and children arranging dating management grated software hardware framework for the access of geospatial data and ser vices through mobile devices via wireline or wireless networks There are two major application areas of mobile GIS field based GIS and location based ser vices Field based GIS focuses on GIS data collection and data validation and update in the field such as adding new point data or changing the attribute tables on an existing GIS dataset Location
18. erface that allows park rangers and resource managers to access and analyze land cover changes and remotely sensed images in the field The most unique feature of this mobile GIS appli cation is the establishment of a wireless communica tion channel between an Internet map server IMS and a mobile GIS receiver Currently most mobile 156 Cartography and Geographic Information Science Internet Map Server on notebook computer with wireless access port Wi Fi wireless communications Field staff Pocket PC GPS and wireless card Figure 2 Wireless local area network solution for mobile GIS GIS receivers Pocket or Tablet PCs provide very limited storage capacity 64Mb to 128Mb for field GIS applications Wireless based IMS can transfer very large remotely sensed images or extensive GIS map layers up to 4GB or 8GB to mobile devices via local wireless communications quickly The link to wireless IMS improves the capacity of mobile GIS significantly Multiple users can access a central ized IMS simultaneously without extra costs Also the IMS can allow multiple mobile GIS users to synchronize their GIS databases at the same time without the need to update GIS data layers and images one by one The following sections highlight the three major elements of this project mobile wireless local area networks customized mobile GIS software and receiver devices and web based GIS content servers Mobile
19. ets that were used to power a notebook computer and a wireless access router The project team also tested the mobile GIS prototype by utilizing a por table battery power station as the source of electricity to the mobile devices Figure 6 Portable power stations have the advantage of having compact configuration and better portabil ity However a battery station can only support three to four hours of consecutive GIS operation which may be a limitation for long term field GIS operations A vehicle based power source can last longer than the portable battery power station The research team tested the battery power source of a mid size sedan which can provide five hours of power support without restarting the engine of the vehicle With the engine running the vehicle s battery could provide longer power support for wireless routers and GIS units Figure 7 illustrates the actual implementation framework for the wireless mobile GIS prototype described here The framework follows a generic architecture of mobile GIS with the server side com ponents being a GIS content server notebook and Internet mapping services ArcIMS The content server was connected directly to a Wi Fi transceiver by a twisted pair ethernet cable The Wi Fi trans ceiver then broadcast the mapping services to and received updated data from the client side compo nents utilizing Pocket PCs with ArcPAD and Pocket Internet Explorer software The complete system
20. f information overload for mobile GIS users and provide automated data conversion and better integration methods for mobile GIS applications A final challenge is the data protection issue in wireless mobile GIS applications Some mobile GIS applications may utilize classified or proprietary GIS data gathered from the field or through access to classified databases The classified information needs to be protected from unauthorized access in both mobile GIS devices and via wireless communication channels Currently there are very few preliminary solutions for the protection of sensitive GIS data such as password protection and data encrypted transmission The real challenge for securing mobile GIS appli cations is to create a hierarchical security framework to define different user groups administrators spe cial access users regular users guests with differ ent permissions to access various security levels of geodata from a single GIS content server Such a solution will require not only the progress of future mobile GIS technologies but also participation from both administration level users and field workers Moreover some field based data such as census tracks and parcel records may involve potential problems of locational privacy Monmonier 2003 For example a homeowner may not want to share his her annual income information with a public utility worker who needs to repair the power line near his her house The GIS community
21. integrated with a global positioning system GPS and act as a client to ArcIMS ESRI 2002 The major challenge in setting up mobile GIS receivers is to create the link between GPS devices and the Pocket PCs The research team tested two types of communication mechanisms a direct serial cable link and wireless Bluetooth connection The first approach used a specialized serial cable for the connection between Pocket PCs and GPS devices A potential problem with this approach is that different Pocket PCs and PDAs require different types of cables which may be difficult to obtain Also the portability of the hand held units can be significantly reduced by the length and potential tangling of cables between the two devices The second approach was to use a Bluetooth GPS card to connect to a Bluetooth capable Pocket PC Bluetooth is a wire less radio based technology for personal device communications over short ranges within 100 meters After comparing the two methods the research team preferred the Bluetooth GPS con figuration over the cable based configuration During the prototype testing several basic GIS functions such as distance measurement and object identification were performed using ArcPAD to illus trate the capability of mobile GIS Figure 4 shows a series of screen shot images captured directly from the Pocket PC using the ArcPAD toolbox The distance measurement example was the distance measured between the SDSU parking
22. ited storage the design of mobile GIS software needs to focus on specific GIS operations such as geocoding address matching spatial search routing services or map display rather than comprehensive GIS functions For example the functional design of LBS software is quite different from the functions provided in field based GIS packages Most mobile GIS software packages are lightweight customizable and can cope with positional systems such as GPS tracking functions Different mobile GIS software may require different operating systems such as Windows CE or Palm OS Geospatial data are customized GIS layers or remotely sensed imagery used in mobile GIS applications With the limited storage space in mobile GIS receivers most GIS data need to be compressed or presented as subsets of their original extents Usually mobile GIS receivers will store geospatial data in a geodata cache located in a temporary GIS storage space or a flash memory card Often customized datasets are downloaded and synchronized from GIS content servers One alternative approach is to utilize wire less communications to access large sized GIS layers and or remotely sensed imagery from the content server directly The advantage of direct wireless access is that mobile GIS users can retrieve the most up to date geospatial information directly from the content server without encountering the complicated data synchronization process between the mobile GIS rece
23. ivers and the content servers The data synchronization wireless communication com ponent is the communication mechanism linking the mobile GIS receivers with GIS content servers These linkages could be real time wireless communications via Wi Fi or cellular phone signals or cable based data synchronization communications via USB or serial ports Both mechanisms should provide two way communications For cable based connections the GIS content servers can send geodata to the receivers stored in geodata cache and the receiver can upload updated geodata back to the content server For wireless communication the mobile GIS receivers can request a specific service or map from the GIS content server and the server will respond to the request by sending the new map to the receiver To facilitate the two way communications several middleware or data synchronization software pack ages such as Microsoft ActiveSync or Web Services are required for mobile GIS applications If both mobile receivers and GIS content servers have networking capabilities the Internet can become a very effective communication channel for mobile GIS applications GIS content servers are stand alone GIS worksta tions or web based servers that provide geospatial data or map services to mobile GIS receivers Most Vol 31 No 3 155 1 r A Client side Components Mobile GIS Receiver local or global Positioning Systems
24. l need to re think the design issues of mobile GIS software and provide more intuitive and user friendly user interfaces for mobile GIS applications One potential solution is to adopt multimedia technologies sound animation and hyperlinks to improve the inherent restric tions on mobile devices Gartner 2003 Also by adopting 3D visualization of landscapes buildings Rakkolainen and Vainio 2001 and using augmented reality in urban environments Haala and Bohm 2003 mobile GIS users could navigate local areas more efficiently and effectively The third challenge is to integrate Internet map ping technologies into mobile GIS Most on line GIS applications were designed originally for desktop clients and standardized web browsers Plewe 1997 Tsou 2004 Many technologies such as Java 2D API Sun Microsystems Inc 2003 Java applets and Microsoft Active Server Pages ASP functions cannot be accessed or executed in Pocket PC environments or require additional plug in software Moreover the heterogeneous software environment of desk top based Internet mapping solutions may become another problem for the integration of mobile GIS applications One possible solution is to follow the OpenGIS Location Services OpenLS specifications devel oped by the Open GIS Consortium OGC 2003a OpenL5 is an open software development platform for location based application services which uti lizes XML based Abstract Data Types ADT and the Ge
25. needs to develop strategic guidelines for the issues of data protection and locational privacy In summary this research demonstrated that an integrated mobile GIS framework can provide field personnel and first responders with mobile geospatial information services that directly support and help optimize their field based collection analysis and resource management tasks Mobile GIS is a very promising technology with strong demands from both field based workers and GIS vendors With the progress of new mobile GIS technologies many future applications such as homeland security emer gency rescue real time environmental monitoring virtual tour guides wildfire management and vehicle navigation services will benefit from and ultimately rely on mobile GIS technology Vol 31 No 3 163 amp l d F Bl 2 Q AHAL el Ol Aa 2 ol ed S S 4 IANA e Layer_1 File Edit Help 0 E n 8 Gaerne i F Value Class_Names _ Color Histogram _Ofunciassiieo a 630954 T egetation gt Ciear ma 9305 sitter gt Clear am ofleat Cover increase EM 16011 afHeraceous gt 1mer 1218 Sferaceous gt Litter slerigniness Decrease 8 Clear gt Litter Road Paved lt a Mt Figure 9 Land cover changes green color near the bicycle motocross recreation site ACKNOWLEDGEMENTS This paper forms a portion of the Integrated
26. oMobility server OGC 2003a 2003b The ADT was created by XLS which is an XML based language for location services There are six major services defined by the OpenLS specifications directory gateway location utility presentation route and navigation services Hopefully the future development of OpenGL can be combined with other types of web services Kolodziej 2002 such as Microsoft s NET Framework or Sun s Java 2 Platform Enterprise Edition J2EE to provide more comprehensive technological frameworks for mobile GIS applications A fourth challenge is to provide intelligent mobile GlServices for different users with the help of software agents Tsou and Buttenfield 2002 Different mobile GIS tasks will require distinct design of user interface Internet mapping technologies and communication channels From a mobile GIS user s perspective it is very difficult to access hundreds of different Internet map servers and to find out about appropriate loca tion services at the same time One possible solution is to adopt software agent technology to help users access or request data images from multiple servers with automated mapping and GIS overlay functions Software agents interact with different mobile GIS devices to provide customized user interfaces to assign appropriate color and symbols for different GIS layers and to search available wireless channels The adoption of software agents might also solve the problem o
27. obal positioning systems use satellite signals to calculate the position of GPS units Sometimes mobile GIS applications may require both types of positioning systems within urban areas to generate satisfactory results Mobile GIS receivers are small sized computers or terminals that can display maps and locational infor mation to end users Their hardware components include CPU memory storage devices input output connections and display screen functions Pocket PCs smart phones tablet PCs or PDAs are the most popular mobile GIS receivers Notebook computers can become mobile GIS receivers if connected to GPS and other mobile GIS components However most mobile GIS receivers require a very small sized hardware device to achieve portability The major differences between small mobile GIS receivers and the traditional desktop personal computer are smaller screen resolutions 240x300 limited stor age space and slower CPU speed Wintges 2003 Some high end mobile GIS receivers equipped with wireless communication devices can be used for data exchange and telecommunications between the receivers and the content servers Alternatively mobile GIS receivers may rely on serial or USB cables to transfer data between the content servers and the handheld devices Mobile GIS software refers to the specialized GIS software packages employed by mobile GIS applications Due to the limitations of mobile GIS receivers smaller display units lim
28. on and Registration ADAR imag ery of the study area within Mission Trial Regional Park Figure 8 via wireless networks Very high spatial resolution imagery Aline sen 1 14p http 130 191 118 58 MTRP form Go Park Ranger ID Types Invasive Plants O animais O Others Pewter l Case Human Interventions Protected Areas New location of Pampas Grass Next to the Visitor Center Upload GIS data O View Tools amp 2 A amp E Internet Explorer 1 15p http 130 191 118 58 _vti_bin sht Go Form Confirmation Thank you for submitting the following information ParkRangerID 23455 Type Invasive Plants Case New Locations Descriptions New location of Pampas Grass Next to the Visitor Center Return to the form View Tools amp 2 4 amp Ej Figure 5 Real time submission of a field survey report via a wireless network such as ADAR offers strong possibilities for creat ing a comprehensive environmental monitoring process Ehlers et al 2003 Large imagery files 160 Cartography and Geographic Information Science Figure 6 The GIS content server when mounted in a vehicle or connected to a portable power station Server side Components Wireless Communication Client side components a Pocket Pocket Pocket PC Figure 7 The implementation framework of mobile GIS were s
29. rating range of Wi Fi signals is up to 100 m 300 feet indoors or 500 m 1500 feet outdoors depending on environmental conditions The wireless LAN in this prototype was used to provide access to the mobile Internet map server and image web server installed on a laptop computer One unique feature of this wireless mobile GIS prototype is that the process of setting the Wi Fi com munication was solely Internet Protocol IP based without relying on Domain Name Servers DNS Traditional web based GIS applications utilize DNS for the naming and searching of machines such as www sdsu edu or map sdsu edu Since local wireless networks do not have dedicated computers for DNS all the units in the wireless network prototype were accessed and identified by their own IP addresses For example the IP address of the notebook web server was 130 191 118 58 and the Pocket PC IP address was 130 191 118 56 The mobile GIS software package ArcPAD used in the project thus needed to specify an IP address to access Internet map services Figure 3 The GIS users could also access the project web site by typing 130 191 118 58 rather than typing Domain Name i e map sdsu edu Customized Mobile GIS Software and Receiver Devices The mobile GIS software used in our prototype is ESRI ARCPAD 6 0 ArcPad is ESRI s mobile map ping and GIS software which runs on portable computers using the Window CE operating system Pocket PC ArcPad can be
30. rer with the submission confirmation Beside the ESRI ArcPAD software there are other commercially available mobile GIS packages such as MapXtend from MapInfo and IntelliWhere Location Server from Intergraph Intergraph 2002 Due to the limitations of research time and budget our prototype testing was limited to ArcPAD for our mobile software testing Web based GIS Content Server and the Implementation Framework The project team created a web based GIS con tent server by installing web server software and ArcIMS 4 0 ESRI 2001 on a notebook computer The server components included a web server Microsoft IIS 5 0 and an Internet map server ArcIMS 4 0 The web server provided HTML form functions for near real time incident report ing as mentioned in the previous section The web server also acted as the middleware between the ArcIMS server and the mobile GIS clients ArcIMS image map server was used to provide Internet mapping services for the ArcPAD software via a wireless LAN Figure 6 illustrates the setting of the GIS content server on the notebook which was mounted in a vehicle or located with a portable battery power station The major challenge in setting up the portable GIS content server was providing an appropriate power supply for the notebook computers and the wireless access router The research team used a 300 watt power converter to convert DC power from an automobile cigarette lighter connection to two AC outl
31. structure and the Geography Department building 102 8 meters The research team also customized the ArcPAD user interface to add new buttons designed for park rangers and environmental scientists using the Application Builder provided by ArcPAD However the research team experienced limitations in the existing GIS functions provided in the ArcPAD Application Builder especially in the low level data communication and networking functions This project utilized both cable and wireless com munication mechanisms between the mobile GIS receiver and the GIS content server During testing GIS layers roads points of interest ecologically sensitive plants park boundary were downloaded directly from a GIS workstation via USB cable con nections Later large sized remotely sensed imagery was accessed from an ArcIMS server by ArcPad using a TCP IP connection over a wireless LAN Also an updated GIS layer was uploaded back to the web server directly via the wireless network Another major customized client side function was the creation of a real time incident report and submission using the wireless environment We utilized the Pocket Internet Explorer and HTML Form functions to create a field survey report with which we submitted field reports to a web server 158 Cartography and Geographic Information Science via wireless communication networks in near real time Figure 5 shows the report form displayed on the pocket Internet explo
32. tic measurements and navigation functions Mobile GIS is an integrated technological framework for the access of geospatial data and location based services through mobile devices such as Pocket PCs Personal Digital Assistants PDA or smart cellular phones With the advancement and convergence of GPS Internet and wireless communication technologies mobile GIS has a great potential to play an important role in field data acquisition and validation Pundt 2002 and in emergency vehicle routing services Derekenaris et al 2001 Today there is a rapidly increasing number of mobile GIS applications being established by private companies Crisp 2003 government agencies and academic research institutes The main users of mobile GIS are field workers and consumers of location based services Peng and Tsou 2003 For example an environmental scien tist in a national park can use GPS and mobile GIS devices to validate add or delete the locations of sensitive plant species A shopper can use a smart phone to locate a nearby shopping mall and create the shortest routing path for navigation to it A police officer can use a Pocket PC to report a traffic acci dent with accurate geospatial locations and send the report directly to the command and control Cartography and Geographic Information Science Vol 31 No 3 2004 pp 153 165 center via wireless networks These mobile GIS applica tions utilize different types of technologies
33. tored in the notebook server and remotely accessed by ArcPAD The test participants performed land cover change assessments and mapping in areas adjoining a bicycle motocross BMX rec reational site white area on the right side image in Figure 8 The second task was to identify potential land cover changes by combining remotely sensed imag ery with GPS A change detection image product called MTRPchange was used to compare ADAR images captured during 2000 and 2001 the new image represented land cover change based on that comparison bebe tp oa L6L Z6L Figure 8 High resolution ADAR imagery from a wireless Internet map server Vol 31 No 3 161 Figure 9 shows the actual land cover changes near the recreational BMX site in the Mission Trails Region Park with the different colors indicating different types of land cover change For example the green color indicates areas of increasing leaf cover within the study area Test participants used GPS to locate their positions on the color coded land use map during assessments of land cover changes around the BMX site The next task was to perform real time update of land cover changes and to send revised data back to the web server via the wireless network Figure 10 Study participants mapped the new locations of invasive plants by recording their locations using ArcPAD correlated with GPS locations The new map data set was uploaded back to the web server b
34. xt section explains the generic architecture of mobile GIS The Architecture of Mobile GIS The architecture of the mobile GIS is very similar to that of the Internet GIS It follows the client server architecture as is traditional in Internet GIS 154 Cartography and Geographic Information Science applications The client side mobile GIS compo nents are the end user hardware devices that can display maps or provide analytical results of GIS operations The server side components provide comprehensive geospatial data and perform GIS operations based on requests from the client side components Between the client and the server there are various types of communication net works such as wired cable connections or wireless communications to facilitate the exchanges of geodata and services Figure illustrates the six basic components of mobile GIS 1 positioning systems 2 mobile GPS receivers 3 mobile GIS software 4 data synchronization wireless com munication components 5 geospatial data and 6 GIS content servers Positioning systems are the devices that can provide georeferenced coordinate information X Y and Z elevation to mobile GIS receivers There are two major systems local positioning systems and global positioning systems GPS Local positioning systems rely on triangulation of the radio signals or cellular phone signals from multiple base stations in order to calculate the position of a device Gl
35. y using a Pocket PC version of File Transfer Protocol FTP software called CE FileCommander Study participants also submitted field reports to the web server using HTML forms This use scenario combined Mobile GIS software ArcPad GPS FTP and wireless network commu nications to create a real time GIS field survey and data update simulation All the participants provided their feedback and comments to the research team during and after the scenario testing The following items are summarized suggestions and observations based on user feedback e Mobile wireless mapping and data editing capabilities are superior to traditional hard copy map editing e It is difficult to create a comprehensive wireless network environment over a wide area such as the Mission Trails Region Park due to terrain effects mountainous terrain and numerous line of sight limitations It is anticipated that the presence of wireless communication dead zones in the field may limit the widespread adoption of mobile GIS e Current software hardware parameter settings for mobile GIS are still too complicated for the general users individuals lacking mobile GIS training e Simplicity is essential to field user acceptance e GPS accuracy needs to be improved to less than a meter to make the application of mobile GIS feasible to various habitat moni toring and environmental resource manage ment tasks and e The graphical user interface is diffi
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