With the release of Topo USA 5.0, DeLorme now offers all the automatic route-planning and navigation tools offered in its fine Street Atlas. These features, coupled with the unique capabilities of a vector map product, can make planning a day on the trail a breeze.
There are two kinds of electronic maps: raster and vector. Raster maps are scanned images of printed maps. They contain all the detail the cartographer thought important to include to tell the story of the space he or she was portraying. Vector maps are mathematical constructs of maps. They are a series of instructions for a computer to draw a map on a screen (or a printer). A vector map is usually made by tracing a printed map. The fidelity of the vector map to its printed parent is a function of the care, cost, and intended purpose of the vector product. This process can create errors as discussed below.
The advantage of a vector map over its printed parent, or its raster cousin, is that every feature on the map is known to the computer that draws it. This means that one can search for physical objects on the map, such as old mines. It also means that you can ask the mapping software to plot a trip from Point A to Point B. DeLorme's products do this very well.
Another feature of vector maps is the ability to update the data relatively simply. For 2005, DeLorme says Topo USA 5.0 has more than 74,500 miles of updated trails. When was the last time the USGS issued an updated topographic map? This handy feature has been enhanced with version 5.0 to include the user's ability to link to objects. This means that you can create a route in Topo USA, then link pictures and trail descriptions to the map.
Topo USA can display more than one map by using a split screen. As we've reported in the past, TopoUSA imports DeLorme's TopoQuad maps (about $100 per state). As can be seen in Illustration 1, a great deal more information is available on the USGS quad of Moab's Pritchett Canyon than in the vector version. Notice that the trail as shown on the right (vector) screen stops south of Pritchett Natural Bridge. The program will not automatically route past that point. However, the USGS Quad (on the left) plainly shows the trail continuing south. How did this omission happen? The DeLorme Topo USA vector maps begin with the small-scale 1:100,000 USGS metric topography map. While the 7.5 minute quad (Illustration 1) depicts a through trail, the small scale 1-to-100 shows the trail as broken.
Topo USA now provides an auto-routable drawing tool. So, to plan our Pritchett Canyon trip, we just draw in the trail and title it Extension. The second illustration shows the extension. A short auto-route has been set up to demonstrate automatic routing. Auto-routing works well with the very effective GPS wizard, which creates waypoints from your route and then loads the data into most popular GPS receivers. Once you return from your trip, you can download your track into Topo USA and attach trip notes and pictures to the file.
Off-highway travel planning has always suffered from old map data. DeLorme has dealt with this problem by providing updated features on its vector maps. With the release of version 5.0, DeLorme adds the ability to download and view orthophoto data. This data includes 10-meter-resolution colorized and geo-referenced satellite photo maps, as well as 1-meter-per-pixel-resolution aerial photo maps, which are geo-referenced. Geo-referencing refers to the ability of mapping software to locate a particular spot on the photo map. These picture maps, coupled with traditional topographic maps, help to provide the most current data.
DeLorme offers this data in a packet called Aerial Data Packet (ADP). The packets are downloaded in units of about 1 square meter. DeLorme provides the USGS Topo Quad for that area, a 10-meter-resolution colorized satellite picture of the area, and a 1-meter aerial photo. For off-highway folk, a meter is not a great distance, so a square meter is not that much data.
Let's say you're planning a trip to Moab and you want some topographic maps of the trails. To map the west Moab area, including Gold Bar Rim, Poison Spider Mesa, Pritchett Canyon, and the rest of the usual suspects, the cost to download the ADPs would be about $290, in addition to the $85 (street price) for Topo USA 5.0. Illustrations 3, 4, and 5 compare the images of the maps supplied by Topo USA 5.0 and its ADPs. In each of the images, a portion of the Poison Spider Mesa overlook trail has been drawn in.
Illustration 3 is the basic Topo USA 5.0 vector image. Note the lack of trail data on the map. Illustration 4 is the USGS Quad map, which plainly shows the trail to the overlook. Illustration 5 is the aerial-photo map of the same area. The trail is not only plainly visible, but the spectacular nature of the overlook's view is also evident.
So, how useful is DeLorme's Topo USA 5.0 for off-roaders? We've used it extensively as a planning tool and like it. The new road- and trail-drawing feature is very helpful in converting vector trails to a set of GPS waypoints. In previous editions of Topo, attempting to use the auto-route feature off-highway could yield some unfortunate results, as the vector maps differed from large-scale topos. The addition of the satellite and aerial maps can help. We must issue a major word of caution, though. The DeLorme vector maps can be very inaccurate in open country; we strongly recommend comparing vector data with either print or electronic topographic maps. Also, maps printed from Topo USA lack a surrounding frame of latitude and longitude scales, so they can't be used for reference on the trail. Always carry printed maps while exploring. DeLorme's Gazetteers are a good choice.
Are aerial and satellite images the new thing in off-highway navigation? Well, there will be more on that topic next month in another review. We'll then offer some conclusions.