Bushwalking Navigation | Documenting Your Route Plan

How do you document a route plan? How can you use Google Earth to check the route and save pics of critical navigational decision points? How do you use mapping software to plot and export the waypoints to your GPS, print the route and elevation graph? How can you annotate your map pdfs? How do you protect your maps from the weather?

This post is part 2 of  Bushwalking Navigation | A Route Plan Workflow

Getting the "big picture"

The first step in planning any trip is to read guide books, talk to other bushwalkers and search  bushwalking forums, websites and blogs to discover which routes are popular. 

Once you have decided on your intended route you will need to check water availability, weather conditions, locate existing tracks, property boundaries and permitted camping spots.  Don't forget to check photographic websites such as Flickr, which give a good idea of popular sites and the scenery to be expected.

Next study the terrain to work out your likely speed, keeping in mind height gains and losses, the density of vegetation, the amount and difficulty of any off-track walking, and the presence of waterfalls in creek lines, which may need to be bypassed.  Once you know these you will be able decide how far apart your camping spots can be and determine each day's starting and finishing times.

I have discussed many of these navigation techniques and route plan design in previous posts (21) and won't go further into detail now.

Finding a Map

You should never rely solely upon a GPS for critical navigational decisions and for this reason bushwalkers should always carry topographic maps covering the route, and the surrounding countryside just in case you get off track. These can be purchased from a local map or outdoors shop, and are usually available at 1:50,000 scale but sometimes at 1:25,000, which provide more detail, for popular areas.

If you are walking the Heysen Trail in South Australia, there are two excellent guide books (Northern and Southern), with log books readily available available which include maps that are adequate for most walkers. The CFS also publishes (Mapland) excellent map books, and these too are available from map and outdoor shops. Many downloadable walking brochures for our parks are available from the Department of Environment's Parks SA website.

With digital maps readily available, many people are using mapping software to select just the relevant parts of maps and to enlarge these beyond the 1:50K scale than is usually available in printed maps, making it easier to see the contour and creek lines. If you are lucky enough to live in NZ, you can download 1:50,000 maps free of charge and even Australia has 1:250,000 maps for free download from Geoscience which are useful for getting the big picture and planning access roads.

Using Mapping Software

My apologies to Windows users for the following Mac centric discussion. 

As a MacBook Pro user I have used MacGPS Pro mapping software for many years to import my scanned maps, plot my routes and export the waypoints to my GPS. A print out of the waypoints file is an essential record of each waypoint's  name, grid reference, comments, and elevation

One big advantage of mapping software is that it is possible to enlarge the map on screen to locate the exact position of known waypoints  or to determine the grid reference to 7 figure accuracy of any point you can see. Once you have decided on your waypoints you can rapidly link these to form a route, calculating distances and bearings automatically by dragging from point to point, and plotting a route elevation graph by selecting the route single click. The elevation graph is useful for estimating time to be taken.

From MacGPS Pro

The disadvantage of using a Macintosh is that without a Windows emulator, such as Bootcamp, and an installed version of Windows, OziExplorer software doesn't work.

For older Macs (not using intel cpu) use Virtual PC or for new OS X Macs with the Intel CPU use either Bootcamp or emulation software called VirtualBox or ParallelsVirtualBox (Sun Microsystems Inc.) is free for personal use. It works in OS X on Intel Macs. (OziExplorer - Running OziExplorer on a MAC or Linux Computer )

There is a way to overcome this and that is to import the maps from the disc in .ecw format into a graphics program such as Graphic Converter, select the relevant part and then save as a PICT or TIFF file.  Some of the .ecw image files are small enough to import directly into a mapping program such as MacGPS Pro.

Often the .ecw image file will be accompanied by a matching .map calibration file and providing you keep it in the same folder as the ecw file, you can then import into MacGPS Pro and automatically calibrate the map. You could of course still do it the old way which was to scan and process a hard copy of the map.

Assuming there is no matching .map file available, calibrating a digital map using MacGPS Pro requires that you first rotate the map (using GraphicConverter) so the northing gridlines are horizontal and then enter the full 7 figure grid references of four widely spread points, usually near the corners of your map.

Top Left:  Easting 0263000 Northing 6540000, Grid Zone 54J, AGD94

From MacGPS Pro

You must also enter the UTM grid zone and know the projection and map datum eg I am using a portion of the Oraparinna map for a forthcoming trip

From MacGPS Pro

NB UTM Grid Zones is SA are either 52 (far west), 53 (west) or 54 (central and east)

Annotating your pdfs

Annotated portion of Oraparinna map

There are several programs (I use Skim) that allow you to annotate a pdf. This is particularly useful as it allows you to add grid references to the margins of your map (NB MacGPS Pro has a menu item "View/Gridlines" which does this automatically for you) and add notes about the route. Most programs allow you to add arrows showing routes and highlights. Once you have done this, you can export as a pdf and if you have the full version of Acrobat take advantage of its ability to reduce the file size significantly, to as much as a tenth.

Using Google Earth to Plan a Route

Google Earth can be used to visualize the route, finding 4WD tracks, checking whether creek lines are heavily vegetated and to see if ridges would be easier going. Cattle, goat and sheep tracks converging on a creek line probably indicates a waterhole, spring or a shallow crossing. Rainwater tanks, galvanised iron shelters, windmills and bores can sometimes be seen in Google Earth, even if they are not marked on the map.

Flinders Ranges: Google Earth screen capture

Simply import your .kml file showing your waypoints and then zoom in and tilt to see your route in 3D. Use a screen capture program, such as  Snapz Pro X, to capture pics of significant parts of the route, with your waypoints shown. Save these to your iPhone, camera or print, for later reference while on the walk.

NB I can never get my GPS waypoints to exactly match those in Google Earth, as I assume it uses a different map datum

Protecting your maps

One of the advantages of printing your maps from pdfs is that you can print them in A4 format which means they can either be laminated back-to-back or placed in a map case without the need for folding.

Other relevant posts

The Bushwalking Navigation series

Other Resources

Geoscience
Department of Environment's Parks SA website
Bushwalk Australia Forum
Friends of the Heysen Trail

  This article by Bush Walker is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported License.