At the end of my very first week working for Blue Marble Geographics, the company had a small party. This gathering was to celebrate the successful release of our latest application for a mobile device, Global Mapper Mobile. As an active, outdoors-oriented person, I could immediately envision how useful an app like Global Mapper Mobile would be; mapping new running routes, hiking, hunting, camping, and of course, backpacking.
On my first trip into the back country six years ago with my wife (then girlfriend), I decided to make our trail maps, as we would be heading into the wilderness. As a GIS student and enthusiast, I was confident I could take what scant data I could find available from others’ trips into the Sage Creek Wilderness of Badlands National Park and make a decent reference map for our trip. While the trip was a phenomenally enjoyable success, I will say we could have saved a few miles with a better map. This memory was fresh in my mind as we planned part of our honeymoon — backpacking the Summit Area of Haleakalā National Park in Maui County, Hawaii. However this time, after earning a MSc. in GIS, gaining experience working in the GIS industry, and most importantly, having Global Mapper Mobile, I was prepared!
The Goal: A Custom Reference Map
While the summit of Haleakalā Volcano is a wilderness, it is nowhere near as vast or remote as the back country in Badlands National Park. Trails of varying quality and some signage would be present throughout the volcanic crater, providing guidance to hikers. What I needed was a custom reference map for our planned hike. I wanted base imagery, with contour lines, our proposed hiking route, way-points, and a way to organize data I recorded from my device’s GPS.
Preparing the Data: Creating a Package File
Global Mapper Mobile requires a package file (Global Mapper Mobile Package or GMMP) in order to transfer data from PC to mobile device. The file is created on the PC in Global Mapper, exported to GMMP format, and sent to the mobile device. In planning for this trip — and really any use of Global Mapper Mobile — I had to organize my goals and properly create the package file to reflect my needs. Having found vector files of the trail we planned to hike, they were the first bit of data loaded into the Global Mapper desktop application. Using them as a reference, the Online Data Tool allowed me to download both base imagery and a terrain layer for the area.
At this point I was able to generate the final features for my map; contours and waypoints. When generating contours, it is important to understand scale. With the increasing popularity of high-resolution LiDAR data, fine scale terrain layers and contours are becoming the norm for many workflows. However, for a map covering over 4,000 feet of elevation change, high resolution contours would have been overwhelming. Since this map is being used for reference purposes and not high-precision work, I felt generating contours every 500 feet was appropriate.
In addition to contours, I wanted to represent our halfway point for this first day of our hike, along with our campsite location. I chose to stylize the campsite in Global Mapper with a built-in point style (Campground). Styles can be retained on export to GMMP, so I would have it on my device.
The last thing to consider, which again can be applied to any use of Global Mapper Mobile, is data recorded in the field and how that will be stored within the application. By default any data created in the field, whether manually or via GPS, will be saved to a default layer. The user also has the option to save it to another loaded layer, however, this has the potential to become confusing if multiple feature types and large amounts of data are being recorded, causing a headache when it comes to layer management. To address this, Global Mapper Mobile utilizes Feature Template layers. The Feature Template layer is created in Global Mapper and can then be exported as part of the GMMP, retaining any pre-determined styling, attributes, and other settings. Recorded field data can be added to the proper Feature Template layer as appropriate. The usefulness of such functionality is workflow- and use case-dependent. When initially creating my GMMP I decided that since I would not be recording a large amount of data in the field, it was unnecessary to create any Feature Template layers. I was comfortable using the default layers created when recording data.
In the Field: Quick Rendering and Recording GPS-Based Data
Standing on top of the Haleakalā Crater at roughly 10,000 feet was breathtaking. It felt as if we were standing on the edge of an alien world. After absorbing the majesty of it all for a few minutes, I decided to put Global Mapper Mobile to the test. The app responded quickly, easily loading the 400MB GMMP. I was able to pan across the entirety of the map, effortlessly zooming to the immediate trail ahead, with the application smoothly rendering my vector data, terrain layer, and the relatively high resolution imagery used for my base map. This seemed the perfect opportunity to record my first GPS-based piece of data, a picture point of my view.
At this point, the phone was packed away for the descent into the crater. As we made our way down the trail, miles of sand contrasted with the green of lush slopes along the crater, as clouds spilled over the crater rim. We approached our rest stop about 4 miles later, after having travelled over 2,000 feet down into the crater. Zooming in to our first rest stop as we approached allowed us to clearly see our location along the trail and even how the vector trail aligned to the bit of trail visible in the base map.
Two miles on from our rest stop, we had scrambled up and over a sandy rise. With another two miles to go before camp, I knew I’d have to put Global Mapper through some more tests today, as our hike out of the crater tomorrow would be much more challenging, requiring my full attention. I decided to create a picture point at the start of our last leg, and then begin recording our trail as we hiked. Global Mapper Mobile quickly opened up and centered on my location, reporting a strong GPS signal from my phone. A quick GPS-based picture point, the start of an auto-recorded line, and we were off. I had strapped my phone to my pack and set the GPS to beep with each recorded vertex, allowing me to “hear” the app running in the background as we hiked. The wind over the edge of the crater drowned it out, but I left the app do its job as we covered the final two miles.
The app successfully recorded the entirety of the last leg of our hike for the day. In the image above, the black picture point can be seen at the start of the recorded trail (black line) as we hiked northwest to Hōlua, where we would camp for the night, before the climb out of the crater the next morning.
Once our tent was set we sat down for a glamorous meal of what I like to call back country chicken curry, which is delicious after a day of hiking. I was able to sit and reflect on the day and all we had accomplished; the personal achievements and experiences … and of course Global Mapper Mobile.
Takeaways: A Successful Trip with a Versatile GIS Application
This was my first time using Global Mapper on a backcountry trip. The application’s versatility was perfect for all I threw at it. The app operated without any issues the entire day. It responded swiftly while zooming and panning across the map. Picture points were created and saved based on GPS locations. The app accurately tracked our path while strapped to my pack via automatic GPS recording for the few miles I had it running. I consider it a success.
Before saving my map, shutting the phone off, and packing it away for the remainder of my vacation, I thought, “Why not, one more picture point?”.
The last picture point of day. Sunset at our camp, located at the base of a nearly 1,300-foot climb we would have to make the following morning.
Jeffrey Hatzel is an Applications Specialist at Blue Marble Geographics. He provides technical support, training, and leads demos and talks at industry events. Prior to joining Blue Marble in 2016, Hatzel earned his M.Sc. in GIS at the University of Wisconsin-Madison. He has experience teaching and studying GIS theory, along with utilizing GIS applications across a variety of real-world settings.