Number 263 - April 2005

GPS and Mapping Software
by Joe Schmitt, Tampa Bay Computer Society
This is the last in a three article series on the Global Positioning System. The first explained what the system is and how it works. The second dealt with GPS units. The third discusses the various software available to interface with the units.    While out on the road or trail, the GPS can be indispensable for navigating. It tells you where you are, where you're heading, and can track distance and speed. When you arrive at an interesting locale, you can mark it with a waypoint. Now all that is great, but one of the more interesting aspects of GPS ownership is the ability to link it with your computer for additional functionality.    In a unit that displays maps, only the most major roads and surface features are pre-loaded. This is known as the base map. The base map cannot be erased and is particular to the region that the unit is purchased in. For example, my Garmin receiver is loaded with a North American road map that contains US highways and interstates. This is great for a long trip, but doesn't really help you around town. Luckily, additional specialized maps are available.    Each of the manufacturers have street level mapping available for purchase; unfortunately, the maps available are almost strictly proprietary. For my Garmin unit, there are instructions on the web to make your own maps, but is a long complex process involving multiple pieces of software. I could dedicate an entire article to that process alone. Another limitation with the mapping software comes with the opening of new roads. None of the software can be updated with the latest roads, so you must purchase the newer version at full price. Be careful though, sometimes it takes a few versions for the newer roads to be displayed at all. If you can live with data that is a couple of years old, places like EBay can be great for getting a deal on some older version.    Even if you do not have a GPS with mapping capability, quite often that receiver can be tied to a computer to process the data it receives. Most units utilize a serial cable to connect to a computer. Although a serial connection is much slower than USB it has been a standard with receivers for a long time and manufacturers are slowly coming out with USB capable units.    In addition to the proprietary software you can purchase from the manufacturer, there are pieces of software that can transfer waypoints and tracks from a GPS. A great waypoint manager, EasyGPS (www.easygps.com), is a free utility that allows you create, edit, and transfer waypoints from your computer. It works with Garmin, Lowrance, and Magellan receivers. Creating a waypoint with the receiver itself can be a long process since the unit does not have a keypad, and you will have to scroll through menus and numbers to set the coordinates. EasyGPS allows you to do this on your desktop computer with the keyboard.    Its bigger cousin, ExpertGPS (www.expertgps.com), displays your waypoints and routes on topographic maps and aerial photos. This software is not free, but you can download a demo. ExpertGPS uses an internet connection to retrieve maps as you scroll around.    There are several places you can get maps for free on the internet. You may already be familiar with some internet mapping websites for street cartography. Arguably one of the most popular is MapQuest (www.mapquest.com), but also popular is Microsoft MapPoint (mappoint.msn.com) and Maptech Mapserver (mapserver.maptech.com). In addition to these street map websites, many others offer topographic and aerial photos. Maptech offers topographic, nautical, aeronautical, and aerial photos, though they'll want you to register.    For topographic maps, TopoZone (www.topozone.com), is a great site that displays maps in various resolutions and datum. TopoZone allows you also to search by geographic features such as mountain peak names as well as city names, states, zip codes, and coordinates. Another excellent site that combines topographic and aerial photos is TerraServer USA (terraserver.microsoft.com). At this site you can flip between maps and photos.    Although these sites are helpful for viewing and printing maps, they do not offer any sort of data transfer with the GPS receiver. For that kind of functionality you must install some software. A great free application available for download is USAPhotoMaps (jdmcox.com). This program	installs on your machine and then uses an Internet connection to download topographic and aerial photos. It can be linked with a GPS to transfer waypoints, tracks, and routes. The maps are compiled from free sites on the web. Be aware, though, that maps are quite large in file size and a slow connection will make getting the maps a long process. Once downloaded, the maps are stored locally on your computer so be sure that you have enough hard drive space.    The next realm in mapping software is independent mapping programs. Two of the most popular stand-alone street mapping programs is Microsoft's Streets & Trips (www.microsoft.com/streets/default.asp) and Delorme's Street Atlas (www.delorme.com/streetatlasusa/default.asp). Both programs offer detailed street mapping in the US and have the ability to link in various ways to the GPS receiver.    Streets and Trips allows you to link to your GPS and display your position on a map. It does not complete data transfer such as waypoints and routes. It has the ability to import data from Excel and text files, but an intermediate program will be needed to get the data from the GPS unit to the file for import. A bonus with Streets and Trips is that also comes with Pocket Maps that allow you to save maps to a Pocket PC.    Street Atlas allows you the same position display with a GPS. In addition to that function, it also allows you to plan a route and provides turn by turn instructions as you navigate. Of course, to be of any use it needs to be installed on a laptop. Unlike Streets and Trips, you must purchase the pocket mapping software separately. Streets and Trips runs about $40 and Street Atlas about $50. I have a copy of Streets and Trips that I got for $20 after a mail in rebate. Both programs are excellent and selection boils down to personal preference more than anything else.    Delorme also makes a topographic program, Topo USA (www.delorme.com/topousa/default.asp). This program runs about $99 and includes streets as well topographic contour maps. The topographic maps are at a 1:100,000 resolution. More detailed 1:24,000 maps, more suitable for hiking, are available on a state by state basis. Your GPS will interact in the same manner as Street Atlas.    A more cost effective way to go for a topographic program is National Geographic's Backroads Explorer (maps.nationalgeographic.com/topo/backroads.cfm) that costs around $40. Although it lacks some of the features of Delorme's software, it does include street maps as well as topographic information. Backroads Explorer also allows direct connection with a GPS for transfer of waypoints, routes, and tracks. It lacks the 3D topographic mapping the Delorme product offers, but it does have shaded relief to better define contours on the maps displayed.    For those that are into creating their own maps there is a program, called 3DEM (www.visualizationsoftware.com/3dem.html), that allows you load elevation data and generate a 3D terrain image. The terrain image can be overlaid with maps to form a 3D map. The primary data used to generate the terrain models are from radar topography. NASA scanned about 95% of the earth's surface during shuttle missions and there is a wealth of sources available where you can download the data. These models can also accept data from your receiver so that you can see a track of where you've been in a 3D representation.    There is lots of additional software available on the market, too many to discuss them all here. A lot of programs offer various ways of linking with a GPS directly or are a great way to search and print maps before you leave on that next trip. There are also a number of utilities which can format data so that it can work with a number of programs.    GPS receivers are innovative and fun gadgets that can really be a powerful tool for navigation. Every day people come up with more interesting uses for the receiver. From handheld to vehicle mounted receivers, these devices are changing the way the man moves through the world. Have fun and I'll see you on the road!    There is no restriction against any non-profit group using this article as long as it is kept in context with proper credit given the author. The Editorial Committee of the Association of Personal Computer User Groups (APCUG), an international organization of which this group is a member, brings this article to you.
Number 263 - April 2005