SatNav for the SilkRoute.

Anybody who has used a SatNav to find their way round the back-streets of a strange city would not willingly do it without one.

For between 80 and 150 Euros you can now (2014) buy a self contained unit to mount on the windscreen of your van that will guide you around most of Europe and North America. "In 200 meters turn left, then immediately turn right." "In 300 metres you have arrived." Easy!

Unfortunately this sort of SatNav will probably not let you find the delightful off-road camp site on the west coast of Mexico at N 18.204445 W 103.118190¹.

Even if your European or North American SatNav will let you enter the coordinates of your destination, most of them will not guide you there unless they have a detailed vector map of the area. Suitable vector maps of most of Asia, Africa, Central and South America have not been available till very recently.

The traditional (i.e. ten years ago) solution to this problem was to use a "real" GPS² with some sort of World map, which, whilst not very detailed, was a great deal better than nothing.

The problem with this solution was that a "real" GPS either had a small monochrome screen or was very expensive. Either way they used proprietary maps, which, if they were available were also expensive.

Three or four years ago to get round this problem many people (including me) used a small Windows notebook computer connected by USB to an external GPS receiver. On this computer we ran software like (PC) Navigator with commercial maps for turn by turn navigation in countries where this was available) and programs like Fugawi or Ozi Explorer where only bitmap maps were available.

Today (2014) several new options are available.

The success of Open Street Map means that vector maps of almost everywhere on earth are available free of charge (in addition to commercial maps).

The advent of powerful smartphones and tablets with built in GPS receivers has added new hardware platforms to the mix.

A stand-alone SatNav remains an option in parts of the world where they are available with detailed maps covering your area of interest. They are simple to use, require little or no technical knowledge to set up and occupy little space. Unfortunately they have many disadvantages for overland travellers. You may not be able to enter waypoint³ data, even manually (e.g. the location of an off-the-beaten-track camping spot you have been told about). You may not be able to acquire/buy maps for country "B" to load into a SatNav bought in country "A". You are very unlikely to be able to record and save your tracks⁵.

A smartphone with a built in GPS can give you all the functionality of a stand-alone SatNav at about the same cost (and you can make phone calls).

A number of navigation apps are available but it is important to choose one that works without Internet access. Google Maps is fine in London but of no use in Mongolia without a phone signal! For worldwide use you need an app that can use Open Street Map data.

For turn-by-turn navigation (with audio direction for the driver) Navigator (by mapFactor) is well worth looking at. (Left: The centre of Ulan Bator (Mongolia) as shown by Navigator using Open Street Map data on an Android phone)

To assist a human navigator (in a vehicle) and whilst walking round a town an app like Maps With Me has some significant advantages over Navigator. Since both apps and their map data are free it is worth having them both.

For more specialist applications Alpine Quest is worth investigating.

To get good GPS reception it will be necessary to have the smartphone as far forward in the vehicle as possible, this may not be the most convenient position for a human navigator to use it. A remote Bluetooth GPS receiver can solve this problem at the addition of some complexity. A smartphone mount and a 12 volt power supply will probably be required.

A tablet with a built in GPS is essentially just a large smartphone and the same apps are applicable. Mounts for tablets are a bit more difficult to find and some tablets can not be powered/charged from 12 volts (only from the mains).

A small Windows notebook computer is still a viable option as an expedition campervan SatNav. However very few notebooks contain a GPS receiver so an external GPS "mouse" is needed. This has the advantage that the GPS receiver can be placed optimally to receive GPS signals (i.e. on the roof with a 360 degree view of the sky rather than the 180 degrees of a receiver on the dashboard.) and the notebook display can also be mounted optimally (i.e. out of direct sunlight for example). A notebook mount will also be required as well as a 12/24 volt power supply. Used small notebook computers are available quite cheaply.

1. There are three common methods of giving the latitude and longitude of a location. Getting them confused can result in considerable error. The easiest method to understand is to use degrees and decimal degrees (DD.dddddd) as above N 18.204445°.
   
   Alternatively you can use degrees, minutes and decimal minutes (DD MM.mmmm). There are 60 minutes in one degree (thank the Babylonians for this, they apparently counted finger and toe joints not just fingers). Thus N 18.204445° converts into N 18° 12.2667'.
   
   The third method is to use degrees, minutes and seconds (DD MM SS). Thus N 18.204445° converts into N 18° 12' 16".
   
   See here for more information and a conversion tool.
   
   
2. The difference between a SatNav and a GPS with maps is only one of emphasis, target market and (often) price. Both perform nearly the same function.
   
   
3. Waypoint: A set of coordinates (latitude, longitude and possibly altitude) that identify a point in physical space. For example a recommended wild camping place. See here for some useful waypoints in Central and South America. Waypoints are also known as POIs (points of interest).
   
   
4. Route: A series of waypoints to be followed to a destination.
   
   
5. Track: A series of waypoints recorded whilst moving.