Maps have been the conventional media for carrying and displaying spatial data for centuries. Changes in data capture, manipulation and display have been rapid since the advent of computer technology. Cartography is a method for carrying dense collections of spatial information in inexpensive, highly portable format. A map can easily be folded and carried in a pocket, annotated to record new data (such as a favorite restaurant or shortcut) and inserted in a book format to expand on a more traditional format. The cartographer's skill is to compile large amounts of data and render it into a map format. It is the data compilation and symbology that are most often overlooked by the spatial information user.

While maps are portable and fairly permanent they are also static. Spatial data, as digital data, are large numeric data files which can be searched, sorted and joined with other sorts of data not immediately seen as spatial. Until recently spatial data could only be managed on a desktop computer.

Geographic Information Systems (GIS) handle spatial data in a database management system, with spatiality (latitude/longitude) simply two of the data variables. A GIS is at once a carrier and processor of spatial information. A key component of a GIS, as it is of conventional cartography, is data capture; another is geo-coding or the ability to assign spatiality to an object. The object can be a house, a stream or an automobile.

Innovations in technology, especially microchip technology and operating systems, have enabled the emergence of handheld technology for spatial information. A handheld computer with Windows CE operating system, a Global Positioning System (GPS) receiver and a link to the Interment are all that are needed in order for remote users to access digital collections in map libraries such as the Map and Geographic Information Center (MAGIC) (http://magic.lib.uconn.edu/).

The difference between a map and handheld digital spatial data is the ability to process data and integrate new data "in the field." This paper will describe these new innovations in technology, describe their emergence in select communities and forecast future trends.

2. MAPS

Roadmaps were ubiquitous. At one time in the United States they were given away free at gasoline stations, and are often called gas-ad maps. Early gas-ad maps are sought out and are considered very "collectible." Now an equivalent is produced either every year, or every other year by State departments of transportation. Folded, they measure about 25 by 12 cm. Printing maps on paper has become expensive. Transportation networks have become more complicated in the past forty years and changes in the network are more frequent. Private mapping companies, earlier hired by the gasoline companies and transportation departments now sell their own maps. A highway map of a city or region can now cost $10.00.

Other maps, such as hiking maps, trail-maps, and topographic quadrangles are in even worse condition than the road maps. They are heavily annotated with trail information, dates and notes of the trip. They are at a larger scale, made for walking, not driving and it takes more of them to cover an area. Typically they are used with a compass in order to locate one's self in the wilderness. I have seen the maps of botanists and foresters covered with notes of species collection and sampling. These maps are about $5.00 each; a backpacking trip can cost over $50.00 in maps.

3. GEOGRAPHIC INFORMATION SYSTEM (GIS)

The natural pride of youth spurs the computer generation to label maps "early GISs". A GIS has been described as, "a computer system capable of holding and using data describing places on the earth's surface. An organized collection of computer hardware, software, geographic data and personnel designed to efficiently capture, store, update, manipulate, analyze and display all forms of geographically referenced information."

A map is very portable, a computer system isn't. A map is quite inexpensive, a computer system isn't. On the other hand; a computer system processes, a map doesn't. A computer system stores vast quantities of information, a map doesn't. A computer systems displays almost instantaneous redraws, a map doesn't. Many of the enhancements of a GIS have been tied to a workstation or a desktop computer. Admittedly high-end notebook computers can go into the field, but at ridiculously high costs.

4. WinCE AND THE HPC

The Handheld Computer (HPC), emerged first as an electronic scheduler and address book. The HPC has become an auxiliary to the desktop workstation.

In April, 1996 Microsoft and Casio Computer announced plans to co-develop products aimed at the consumer market. The two companies promised to collaborate on the architecture for a new category of computer-based consumer devices designed to connect to, and share data with, Windows-based PCs. Microsoft developed system software, applications and development tools for these devices, while Casio built the hardware and leveraged its expertise in the consumer electronics market. While Casio had built its base on economy-sized consumer devices, Microsoft had struggled to port Windows to the handheld market. The software giant has repeatedly stated that it plans to create a new line of operating system and application products specifically for personal digital assistants.

Since 1996 the power of HPCs has grown. Now, with several vendors in the marketplace, the prices are competitive, often under US$500. The Hewlett Packard 320LX, for example, has 640 x 240 (1/2 VGA) screen resolution, SH-3 RISC 44MHz CPU, and comes standard with Microsoft Pocket Word, Microsoft Pocket Excel, Microsoft Pocket Internet Explorer and Pocket AutoRoute. In January, 1998, Microsoft consumer platform group Vice President, Craig Mundie, reported that handheld PC vendors have sold 500,000 Windows CE devices since the operating system debuted in late 1996.

Microsoft Windows CE is designed as a general-purpose operating system for small devices, which are typically diskless systems with a limited memory capacity. Windows CE is adapted for a specific hardware platform by creating a thin layer of code that resides between the kernel and the hardware. Unlike other Windows operating systems, Windows CE does not represent one standard, identical piece of software that is common to all platforms. To be flexible enough to meet the needs of a wide range of products, Windows CE is modular. This means that it can be custom-built for a product by selecting from a set of provided software modules.

One of the most exiting developments in version 2.0 of Windows CE is the addition of color. The new Windows CE supports the full range of colors available in other 32-bit Windows platforms. The color range available to a display device or operating system is determined primarily by the pixel depth that it supports. For maps and images, inherently graphical, this advance is key, as we will see.

5. PORTABLE MAPPING

As previously mentioned, Windows CE comes with a mapping package. Pocket AutoRoute is based on the mapping done by the United States Bureau of the Census for 1990. The TIGER coverage, at a scale of 1:100,000, is in the U.S. public domain. This data set has been widely developed by commercial developers. Other software developers have used the TIGER data and Global Positioning System (GPS) hardware to enable the user a dramatic new development in using portable mapping

6. GLOBAL POSITIONING SYSTEM (GPS)

The global positioning system is a satellite-based navigation system consisting of a network of 24 orbiting satellites, eleven thousand nautical miles in space, in six different orbital paths. The satellites are constantly moving, making two complete orbits around the Earth in just under 24 hours. If you do the math, that's about 1.8 miles per second.

The GPS satellites are referred to as NAVSTAR satellites. The following basic information on GPS should be of interest:

One of the biggest benefits over previous land-based navigation systems is GPS works in all weather conditions.

So what information does a GPS satellite transmit? The GPS signal contains a 'pseudo-random code', ephemeris and almanac data. The pseudo-random code identifies which satellite is transmitting--in other words, an ID code. Satellites are referred to by their PRN (pseudo-random number), from 1 through 32, and this is the number displayed on a GPS receiver to indicate which satellite(s) being received. So why there are more than 24 PRN numbers? This simplifies maintenance of the GPS network. A replacement satellite can be launched, turned on, and used before the satellite it was intended to replace actually fails! They simply use a different number (again from 1 through 32) to identify the new satellite.

Ephemeris data is constantly transmitted by each satellite and contains important information such as status of the, current date, and time. Without this part of the message, a GPS receiver would have no idea what the current time and date are. This part of the signal is essential to determining a position, as we'll see in a moment.

The almanac data tells the GPS receiver where each GPS satellite should be at any time throughout the day. Each satellite transmits almanac data showing the orbital information for that satellite AND for every other satellite in the system.

By now the overall picture of how GPS works should be getting much clearer. Each satellite transmits a message which essentially says, "I'm satellite #X, my position is currently Y, and this message was sent at time Z." Of course, this is a gross oversimplification, but you get the idea. Your GPS receiver reads the message and saves the ephemeris and almanac data for continual use. This information can also be used to set (or correct) the clock within the GPS receiver.

7. SOFTWARE

When we put the spatial data together with the Handheld PC, the GPS receiver and the Windows CE operating system we have a platform capable of performing real-time mapping. There are a few mapping software packages being developed for HPC platform. The most usable at this time is TeleType GPS*. This product is sold in two components: the viewing software and the import software. Each have distinct processing functions.

The viewing component allows the user to zoom and pan, two elements that move the data spatially. Zooming can take the scale ratio from 1:25,000 to 1:2,500, panning moves the screen from one location to another. The viewing component also allows the user to collect "waypoints," or XY coordinate points gathered from the GPS, and display them on the screen. This ability to capture data is a key element, making the HPC an auxiliary to the desktop computer. The data collected in the field can be transferred to the desktop, imported into a GIS, or other program, and processed at a higher level.

The other component, the import software, enables the user to download data and import from MIF, the MapInfo import format, into TTM, the TeleType format. MAGIC collects and makes available spatial data at a scale of 1:250,000, 1:100,000, 1:24,000 and beginning to collect 1:2,500. This data, over 6 Gigabytes for the State of Connecticut, ranges from very sophisticated soil data to general population data. An average of 2.5 Gb are requested monthly, in about 4,500 files. The software enables a researcher taking a digital airphoto into the field and locating specific tree specimens and logging detailed information about the specimens.

8. CONCLUSION

Does this replace the paper map? It could, until the batteries ran out. But the replacement of paper is not really the issue. A better question is "Does it enhance the spatial information system that is the map and map user?" Yes it does, because it processes information. Computers process. They process vast amounts of information quickly. The HPC with GPS processes time and place and space and displays that information on a map, or in a spreadsheet, or Word document, day or night. This cheap mobilizing of computing is a key step for mapping. What the computer has done for Geographic Information Systems, the HPC will do for maps.

I have quickly covered a New Information Technology for spatial information. It is user based. The impact on libraries will be varied depending on the role libraries take in the Information Age. In the United States, freedom of information and information in the public domain have made spatial information, in particular, readily available to a broad user community. The library, however, determines its service relationship to the user. In Connecticut, the Map and Geographic Information Center has taken a strong stand toward determining that libraries are best suited to arbitrating the users spatial information needs.