Landmarks consist of topographic features or man-made objects and signs such as buildings and tire tracks. Tire tracks can give a host of information on the vehicle that has created them; soft rounded edges mean the tracks are old, while sharp, crisp tracks mean a vehicle has passed merely a few hours ago. A close look at small pebbles on and around the tracks can give an indication of the direction of travel. When driving in the desert with a group of vehicles, it is necessary to study all the tires to be able to recognize later which tracks belong to whom; a good way of finding a car that has strayed from the group. The same applies for persons and footprints.

Landmarks do not look the same from every direction therefore it is a good idea to look back every now and then while driving or walking to see what the landscape will look like on the way back.

The sun can be used as a reference to identify the desired travel direction; corrections have to be made at intervals to allow for the sun's movement. Stars can give a more accurate indication; the North Star or Polaris in the Northern Hemisphere and the Southern Cross in the Southern Hemisphere are fixed references irrelevant of time.

The wind can also be used as a navigation tool but is highly unreliable and requires a thorough knowledge of local weather conditions.

A compass and a good map are your basic navigation tools when driving or hiking on unfamiliar grounds. Stop often, look at the map and make sure you are going where you set out for. Good working knowledge of map reading and compass operation is of course a must.

The Global Positioning System or GPS, is an affordable, easy to use and fairly dependable means of navigation. A GPS unit basically uses the good old triangulation method to give the geographical coordinates of any point on earth by receiving and processing signals that are sent from a number of satellites orbiting the earth.

The basic function of a GPS is to give latitude and longitude coordinates; any point defined thus is called a "waypoint". In addition to latitude and longitude a GPS also gives present time, sunrise and sunset times, altitude, distances between waypoints and speed of travel together with a host of other data depending on size, make and model. Waypoints can be stored and retrieved; a number of waypoints can be grouped into a route.
The processing functions of a GPS unit can be greatly enhanced by connecting it to a computer; software is usually available by the manufacturers themselves, there are also some independent software developers who, I must say have produced programs with very powerful and user-friendly features.
However good a GPS is, in the desert anywhere in the world, nothing can replace an experienced local guide. A GPS will tell you to follow a given course but cannot know the conditions of the terrain, especially after weather disturbances. Rain will leave the sand hard packed and easy to drive on but under a layer of dry sand you may find deep mud, sandstorms will make the sand soft and fluffy and easy to get stuck in. Sand dunes shift and move constantly, therefore a route that crosses a dune field may need revising every now and then (a dune field can be several hundred square kms/miles or just a few hundred meters/yards). So to define the general direction of travel, the GPS will do a great job but you must always keep an eye out for surprises.
When uploading waypoints from your computer into the GPS, always print a hard copy of the files and take it along on your trip, and when driving or hiking with your GPS always look around you and record a visual image of the landmarks you see.

The GPS is a major breakthrough in navigation equipment but as with any other tool, will only be useful when used intelligently. Remember that an overcast sky may reduce the performance of your unit, also for no apparent reason you may get, every now and then, an error message such as "receiver failure" (very stressful, I can tell you!).
Therefore even if you rely on you GPS to take you to your destination and back home, always keep your mind alert and your eyes open; by making use of all possible navigation tools simultaneously you will be stacking odds in your favor.

When in doubt about the route to follow, stop immediately, consult your map, think, and do not proceed unless you have a fairly good idea as to which direction you want to go. If you do not seem to recognize the surroundings go back a few kilometers (miles) until you see familiar landmarks, then resume your progress. Chances are you missed a small detail on the way. Never proceed blindly in the hope of finding your way further ahead