1.2 Data Access .
Viewed from a technological perspective then, we can easily connect the mobile field application into the existing structure of the enterprise GIS. We still have the GIS engine, that resides on a powerful, centralized server, carrying out the main data management role and providing the underlying application development software for spatial analysis and query operational. The GIS engine feeds data into the organizational network for all with access to the enterprise and the mobile field application simply connects to the enterprise to access the same data as and when needed. This connection is usually a physical connection either directly to an office based computer, or via an Internet connection
The Internet, of course, is used by the entire GIS for the distribution of data throughout the entire organization and, ultimately, from business to business. At this point, however, the mobile field application is not interacting seamlessly within the context of the network, but must take a copy only of the data that everyone else sees and operate it's own resident application to process or use the data
Moving forward, the seamless interaction of the mobile field device as part of the enterprise network itself will eventuate through the utilization of wireless technology. Ultimately, we could see the field application operate as a web-browser, where it's interface and analysis is carried out on the GIS engine, being served up to the field application in its entirety. But that's a long way off.
What we're likely to see is a small operational application and some resident base data on the field device. The field device will only interact with enterprise when data is updated or when new data is required to be viewed or queried. Wireless technology, however, isn't quite there yet, and in fact seems to have slowed down with the associated economic slowdown, so we'll take it out of the picture for now.
Whether wireless or not though the ability for the field application and device to be aware of its location is a significant factor in the ultimate success and acceptance of mobile GIS for operational efficiency. We'll investigate this in more detail later and look at the main functions of personalization, data management communication, and spatial analysis that location provides to mobile GIS
2.The Mobile GIS System.
Mobile GIS is a system. The field application component should not be thought of a limit of mobile GIS. It is dependant on the underlying GIS engine; utilising its power in much the same way as the broad enterprise business system. Mobile GIS can be considered an extension of the enterprise GIS. Largely due to technological restrictions however, it currently uses only a subset of the entire GIS to carry out tasks focused on specific field based operations. The mobile GIS user interface is therefore relatively simple up-front, being very task-oriented and specific, but (and especially as wireless technology becomes more robust) relies on the powerful back-end processing of a GIS engine to carry out more complex queries and analysis. Field devices are restricted in terms of processing power and storage capacity, which restricts the field application to a relatively lightweight, thin-ish application or client, but again the completeness of operation for a mobile GIS comes about through the interaction of the fully-functional GIS host to provide robust data management and analytical operations.
3. Field Device Considerations.
Mobile GIS is a system then ,I'd like to shift the focus now to the field and consider two important pieces that will be used by the ultimate operator of the mobile GIS: the field device and location.
3.1 The field Device.
The Field Device is the mobile workforce's personal computer. But whereas an office based PC operates in a clean, stable environment, the mobile environment that the field device must be used in is significantly different, and must be considered. It must operate in environmental conditions that are harsher than an office environment. For each individual user, these conditions will vary in levels of harshness, but there are definite risks involved with equipment failure in any situation where equipment is being moved. When considering which device is best for the environment it's going to be used in, think in particular about the ability to view graphics and text on the screen and what will happen if the device is dropped on the ground? Concrete surfaces are hard. When thinking about the environment think also about the value of the data you are gathering or updating. If you drop your device and it breaks, can you
retrieve the data you've been working with? Also, how much data can you store without having to return to the office? GIS is very graphically intensive - so will be mobile GIS. How well will your device be able to cope with large quantities of graphical data?
Finally, as with office based PC's field devices are settling onto a standard operating system - predominantly Windows CE. A standard operating system provides stability that encourages the development of commercial applications, in turn encouraging growth. When considering the underlying technology for your device ensure it adheres to the standard of the day, otherwise your choice of applications will be very small or, if you're a developer, your market will be small.
While few devices offer the complete solution, try to use devices that have integrated componentry - especially hardware components housed in the same unit. Consider the fundamental components important for your task and look towards devices that best meet your ergonomic and operational needs. If scanning barcodes is central to your application's success, consider a Windows CE device that has an integrated scanner. If location is important, consider an integrated GPS receiver within your Windows CE device. The easier the device is to use for your field personnel, the greater the level of acceptance. Also, the more integrated the main components are within your handheld device, the less chance there is of damage due to the likes of cables getting caught on branches,
3.2 Location Awareness.
Location has an important part to play in mobile GIS and the ability to integrate location into both your field device and the application that will operate on the device offers significant benefits. The significance of location is well understood for GIS. Location has just as much significance and then some for mobile GIS.
There are three main areas where reliable, real-time definition of location is important: Personalization, Spatial Analysis and Data Management. As wireless operations become more robust and prevelent, communication of the data as part of the management requirement will also rely on location
Location is used to uniquely identify - or personalize - both the device and the operator of the device. Where you are helps determine which application you should be running and what you should be seeing on your application. Location can be used to automate a lot of the operations that are associated with both analysis of the region in space you are concerned with and the manage access to data that is needed to make the
analysis meaningful. Eventually, as wireless becomes a reality, the ability for your device to know it's location allows for efficient, automated data transfer as and when needed without clogging up bandwidths.
4. Conclusion.
There are three main points
- Mobile GIS is an extension of the enterprise. It's part of a system, and in fact is dependant on a system for its success. It's not an island unto itself. It's useful to note that while wireless will be very useful for mobile GIS in the future, it's not essential, at present anyway, for successful operation.
- The field device is an integral component of the mobile GIS system. It needs to be robust and based on sound standards. When considering the right device to use, don't forget to think about just how valuable the data that resides on it is. Can you afford to lose a day's data if the field device breaks or crashes?
- Finally, location is central to the operation of mobile GIS - even more so than your office-based GIS - as location will ensure the efficient management and use of data on your field device and between the field and the office. Both now and even more so into the wireless future.
Mobile GIS means "GIS-enabling the workforce where they work with the tools and data they need when and where they need it."
4. References .
- [1] Wei Zhongya, Xu Suning,Wu Lun, 2003. A WAP-basedGeographic Information Mobile Service. CommunicationTechnology Proceedings, ICCT 2003. International Conference
on, Vol2: 1455-1460
- [2] Mao Haifeng, 2004. Distributed GIS for Agriculture Based on J2EE. Geomatics and Information Science of Wuhan University,29(2): 142-143
- [3] Location Interoperability Forum, 2002. Mobile Location Protocol Specification.
http://www.openmobilealliance.org/lifdownload/LIF-TS-101-v3.0.0.zip (accessed 18 May 2003)
- [4] Gong Jianya, 2001. Concept and Development Trend of Spatial Database Management System. Science of Surveying and Mapping, 26 (3): 4-9