Field Navigation Archives

Finding your way, recording your hike

Avenza on iPhone. Also works on Android. Custom geopdf generated from CBJ LiDAR, with 2-foot contours. On launching, remember to Record GPS Tracks. In Plot Photos you can name pics and create photopoints. On completion, email yourself or friends a zipped kmz with the track and points.

Many of the maps viewable and downloadable from JuneauNature are centered on popular trails. Trails are cool. I’ve written a 72-page guidebook about them. But on page 65, I admitted:

‘Juneau’s trails are wilderness training wheels. Ultimately, good hunters, gatherers, naturalists and visionaries step off the trail.’

Should you try that, I recommend a geoPDF.

GeoPDFs

My favorite way to navigate is currently by means of personally-designed geoPDFs, viewed in the free app Avenza. A geopdf is a ‘smart-pdf’ containing spatial coordinates. Using the GPS on your phone or tablet, you can display your position on these custom maps, laying down an orange trackline, or take waypoints. Pictures taken from your device display on Avenza maps as thumbtack photopoint icons. These are later exported along with the track to kmz for display on Google Earth, or converted to shapefile for use in ArcMap.

Once Avenza is installed to your phone, download one of my dozens of custom geopdfs, or, say, a free USGS topographic map in geopdf format. Once it’s loaded, tapping that upward arrow on the footer, you’ll be asked which of a number of apps to open it in. Scroll over to the Avenza icon. It’ll take awhile to format but when finished, you can open that mapview and begin to explore the simple Avenza menus.

Recipients of your google earth kmz can scale in and out, and open each photo by clicking the named thumbtack icons

In my Media types > Maps section, most of the linked maps are geoPDFs. I’ve exported them from ArcMap for popular hiking destinations throughout Áak’w Aaní—and a bit of Chilkat country as well. Some are based on high-res orthophotos; others are on LiDAR- or IfSAR based hillshade, overlain with layers such as streams, fine contours, geology, trails, etc. I like to load one of each to my phone or tablet for hikes, and often alternate between them depending on whether I’m considering landforms or vegetation cover. The free version of Avenza holds only 3 geoPDFs at a time. We just have to clean off the old ones and load the new ones before each hike.

Stay tuned to this page as I build out the geoPDF collection. My goal is to prepare them for many of our local trails and all of the surroundings of public schools—places where Discovery Southeast naturalists bring students on field trips.

Advances in GPS

Only 10 years ago, GPS was pretty sketchy in the dense Southeast rainforest, sometimes losing reception altogether under particularly tall trees, near steep hillsides, and at certain ‘weak’ times of day. But today, more and more devices include GLONASS, Russia’s version of America’s GPS. This has improved reception at high latitudes, and in dense forest.

Even my android tablet has a pretty good GPS, suitable for navigation. But at the end of a survey, or simple recreational hike, I like to download a more accurate track, which is then used to generate better photopoints than I can get from my phone or camera. Since 2016 my solution has been to place a tiny bluetooth GPS in a billcap pocket or high in my daypack. The Bad Elf GPS Pro+ is a fraction of the cost of survey-grade (sub-meter resolution) devices and delivers comparably convincing tracks under canopy. More on GPS and navigation in general is in Ground truthing methods.

Tracks and trails

The trails layer in my CBJ ArcMap project is a work in progress. Building off the USFS layer, I’ve been slowly fine-tuning it with Bad Elf tracks, and—where trails show on aerials and LiDAR hillshade—by tracing from high-res 2013 orthoimage &bare earth. If you have more accurate tracks for any trail on my GeoPDFs, email em to me, as .gpx, .kmz, or .shp.

Note to Chilkat ground-truthers, spring 2020

Avenza will be a great way for you to send me your observations as we build a biogeographic atlas for the GCW. Got a mystery track? Cool bird sighting? Bedrock outcropping? Cutbank layer-cake? Panorama of an unusual forest type? Zip up your GPS track-&-pics and send me a kmz.

And if my small initial collection of Chilkat-region geopdfs doesn’t include a detailed map of your favorite hiking/boating area, let me know. I’ll post custom geopdfs—on both orthos and bare-earth, with whatever combination of vector layers you need.

Downside of gadgets

I love my navigation toys. But let’s close with a caveat about technology, adapted from a sidebar in our course manual What would Raven see:

Sitka anthropologist Richard Nelson remembers that when younger Inuit first began to use compasses, the elders worried. The compass, they claimed, was weakening peoples’ intimacy with their treeless northern landscape. No longer could hunters orient themselves by the concordance of subtle natural signs, such as the way snow deposits in prevailing winds. The compass was in some ways weakening peoples’ relationship with their environment.

Today the compass—once ‘cutting edge’—is now increasingly left behind by outdoorspeople armed with more advanced navigational tools. As of 2015, even dedicated GPS units are being displaced, because our phones and watches ‘can do all that.’ But does ever-advancing technology place even more buffers between the navigator and the terrain? Few would suggest we abandon useful tools such as compasses or GPS units. But we should remember Adaa analgéin—Raven’s way of studying the world. Do our tools sharpen or dull our perceptions?