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Mobile GIS technology update  Figure 3. Accuracy testing of Handheld GPS on cell phone towers, downtown Nanjing, China. The convenience of the handhelds makes it is possible for workers to climb the towers, while the GPS accuracy ensures that China Unicom add only the very best information to their GIS database. GPS is subject to a number of errors most of which can be removed through a process known as differential correction. Differential correction can be applied to GPS positions as they are recorded in a process known as real-time differential correction. For Mobile GIS applications obtaining accuracy in real-time is valuable for reliable navigation and spatial queries. A new Satellite Based Augmentation system (SBAS) is being developed for Japan and Eastern China that will provide free real-time accuracy to SBAS capable GPS systems. The satellite, named MTSAT (multi-functional transport satellite), is expected to launch in November 2004 with first operation in January 2005. SBAS is already well established in the United States (WAAS) and Europe (EGNOS). In the United States American Electric Power’s (AEP) has a Mobile GIS system that incorporates a convenient form-factor, a high quality GPS solution and an open Windows Mobile software system. AEP requires real-time sub-metre accurate positioning to stake-out lines of power poles across vast featureless areas of the southern United States. GPS supplemented with SBAS is the most cost-effective way to achieve this. The open operating system allows AEP to run custom Pocket Designer software. Pocket Designer was built for AEP by GeoSpatial Innovations, a software development firm specialising in mobile solutions for Utility companies. Pocket Designer allows AEP workers to lay out poles productively. Real-time GPS allows AEP to stake a pole line through brush much faster than they could with traditional methods. Carl Livingood, President of Geospatial Innovations states that using this Mobile GIS system “they have recorded field savings as high as 75%” over traditional methods. Rugged and portable computers Mobile computing has advanced considerably in the last decade with Personal Digital Assistants (PDAs) becoming functionality-rich to the point where operating systems such as Windows Mobile software provide many of the features of their desktop counterparts. In addition, the low cost and high portability of PDA-style devices makes them the preferred option for most mobile workers. There has been some convergence between PDA’s and mobile phones, with the introduction of the Smartphone, but while such devices are highly portable and optimised for wireless communications, they typically lack the rugged specification necessary for Mobile GIS applications. One feature that distinguishes Mobile GIS from other mobile applications is that workers are always outdoors, and can be exposed to harsh elements. Another often overlooked requirement when assessing hardware is the ability to read a display in bright sunlight. Field computers that can be thrown around in the back of a vehicle, survive heavy rain or operate in sub-zero or desert-like temperatures and continue to operate, are critical for mobile GIS.  Figure 4. The Rugged GeoXT handheld is used to monitor the spread of Schistosomiasis by the National Institute of Infectious Disease (NIID) in Japan. The often wet conditions required a rugged and waterproof computing platform. Ruggedness tends to add to the cost of a field computer. However, this is offset by reduced downtime, fewer return visits due to field failures or bad weather, and increased security of data. Also, in contrast to low-cost PDAs, ruggedised systems designed for Mobile GIS work, typically have sufficient battery-life for a full-day’s work in the field. In the past, the only mobile computers that could withstand the rigours of field use were heavy, power hungry and cumbersome. The offerings were typically customised for a specific application and often used a proprietary operating system. The convergence of PDA functionality and tough environmental specifications, coupled with improvements in battery performance, has allowed the development of field computers ideally suited for Mobile GIS. Wireless technology for mobile GIS Wireless data networks are a key requirement for Mobile GIS applications. Services such as GPRS provide a per-byte rather than per-minute rate, meaning that you pay only when data is transferred. This is ideal for mobile GIS applications as you may wish to be constantly connected to the enterprise data source, but only pull/push data over the network on an intermittent basis. Mobile phone network coverage, including 3G CDMA, GSM and GPRS data services, are now widespread in Asia. Figure 5 illustrates the level of GSM coverage in North East China. Note that high quality coverage is predominant.  Figure 5. GSM coverage in North East China3 Mobile phones have become a consumer commodity and are becoming increasingly “smarter” with PDA-style functions such as email built in. While an excellent platform for the delivery of data over a wireless network, Smartphones typically lack the durability, or battery life of today’s rugged handheld computers, making them less suitable for GIS data collection or Mobile GIS applications. Another option for wireless data transfer between the field and the office is using a standard mobile phone in conjunction with a rugged handheld. With this method there is the added advantage of being able to change your phone without changing your whole computing platform. Bluetooth technology, increasingly standard in mobile phones, provides the ideal solution for cable-free communications between the mobile phone and the field computer. Bluetooth is a short-range wireless protocol for communication between mobile devices, replacing serial cables. In this setup, the field computer communicates with the mobile phone over the Bluetooth connection and the mobile phone communicates with a central server or Internet portal to access enterprise data. Mobile GIS software Access to enterprise data is governed largely by the GIS software solution. Today, every major GIS company has a mobile application for taking GIS data into the field. Functions most commonly provided in Mobile GIS software include the ability to:
 Figure 6. Environment Canterbury mobile GIS architecture. Conclusion Mobile technology uptake in Asia is expanding exponentially with more and more people increasing productivity by working wirelessly. The emerging trend is towards using data services and wireless Internet connections to access enterprise data. As technology advancements, such as wireless network services, enable more organisations to take advantage of Mobile GIS, it is clear that the deficiency in enterprise geographical data is hindering development. To remedy this a system that can provide both GIS data collection and Mobile GIS capabilities is an attractive way forward for many companies. Rugged and portable computers with integrated high quality GPS are now available running the industry standard Windows Mobile 2003 operating system. That convergence of technologies allows companies to deploy their workers with GIS data collection or mobile GIS capabilities, with enterprise data being delivered over mobile phone with Bluetooth connectivity to the handheld. Once fully operational Mobile GIS provides a competitive edge to service provision to customers, increases productivity and ensures that data is always up to date for critical decision-making. References
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