More About the Map

The map has been compiled from various sources:

  • Over 300 gps tracks from The Friends of Mount Athos path-clearing team, as well as other information gathered on the ground.
  • Digital elevation data from the SRTM Mission (NASA); Public Data from KTIMATOLOGIO (Greece); Imagery from the Pleiades System – Airbus Defence and Space; and study of old and new maps of the Holy Mountain.

We are continuing to add information, with the intention that this will form a GIS for the Holy Community.

Data has been processed using Globalmapper, Natural Scene Designer, Corel DESIGNER, and other utlities, and printed with either a CANON iPF6400 or a CANON imageRUNNER with a Fiery RIP. All data not in the public domain has been used within the limitations specified by the owners. There are no abuses of others’ copyright in this work.

At this stage all maps are ‘print on demand’. This means that there will be constant refining of the maps for the immediate future.

We accept that there will be errors in the information and they will be of several types: simple mistakes, deliberate omissions (this will be at the request of the Holy Community), and ficticious inclusions (for the identification of copyright breaches).

We will respond immediately to any questions, and welcome involvement in continuing development.

Do not forget that the maps have accuracy limitations due to the accuracy of data used (new satellite imagery has a ±60 cm resolution), rectification errors, particularly in rugged terrain and because of the need for generalisation (simplification) around complex features.

Map errors plus gps limitations require the pilgrim to look where he is going!

The UTM coordinate system The map is marked in 1Km (1,000m) grids, in the UTM projection. In addition, each cell is identified horizontally (by numbers), and vertically (by letters). These co-ordinates are used in the gazetteer, as a way of locating buildings and landmarks.

The UTM system divides the earth into 60 zones each 6 degrees of longitude wide.

Each zone is divided into horizontal bands spanning 8 degrees of latitude.

A square grid is superimposed on each zone. It is aligned so that vertical grid lines are parallel to the center of the zone, called the central meridian.

UTM grid coordinates are expressed as a distance in meters to the east, referred to as the “easting”, and a distance in meters to the north, referred to as the “northing”.

UTM easting coordinates are referenced to the center line of the zone known as the central meridian. The central meridian is assigned an easting value of 500,000 meters East. Since this 500,000m value is arbitrarily assigned, eastings are sometimes referred to as “false eastings”.

UTM northing coordinates are measured relative to the equator. For locations north of the equator the equator is assigned the northing value of 0 meters North. To avoid negative numbers, locations south of the equator are made with the equator assigned a value of 10,000,000 meters North.

Frequently, in land navigation, the zone information and the digits representing 1,000,000m, and 100,000m are dropped. The 1m, 10m and 100m digits are used only to the extent of accuracy desired.

In our maps, the format of the information is, for example – UTM 35N 262893E, 4466396N (the courtyard of Vatopedi Monastery!)

The use of GPS devices
A GPS unit accurately triangulates your position by receiving data transmissions from multiple orbiting satellites. Each geo-located satellite broadcasts a standard, co-ordinated time signal. The differences in these signals when they arrive at your GPS is the data for the position. Obviously, the further apart (or lower down the horizon) the satellites are, the better the location fix. Your location is given in coordinates: latitude and longitude or Universal Transverse Mercator (UTM).

Point-to-point navigation:
A location or destination is called a waypoint. For example, you can establish a starting waypoint by using the location function. If you have the coordinates for where you are headed, a GPS can give you a straight-line, point-to-point bearing and distance to your destination. Since paths rarely follow a straight line, the GPS’ bearing will change as you go. The indicated distance to travel will also decrease as you approach your goal.

Route navigation: By combining multiple waypoints on a path, you can move point-to-point with intermediate bearing and distance guides. Once you reach the first predetermined waypoint, the GPS receiver can automatically point you to the next one or you can manually do this.

Keep a Track: One of the most useful functions of a GPS unit is its ability to lay a virtual breadcrumb path of where you have been, called a track. This differs from a route, which details where you are going. You can configure a GPS to automatically drop “trackpoints” over intervals of either time or distance. To retrace your steps, simply follow the GPS bearings back through the sequence of trackpoints.

Key Concepts: A GPS receiver does NOT replace a map and compass or the knowledge of how to use them. Your GPS unit DOES augment and enhance your navigational abilities with technology. But you should still always carry a detailed map of the area and a compass.

Acquiring Satellites
To provide reliable navigational information, including your position, a GPS receiver needs to receive good signals from at least four satellites. The Satellite screen will display the current configuration of the satellites and the strength of the signals. It may take several minutes for the GPS unit to lock in to the satellites, so be patient. If you see only a few satellites and weak signals, then do not rely on the GPS’ directions. Use your map and compass. A clear view of the sky is best for an optimal satellite lock. Tree canopy and buildings that obscure the view overhead or of the horizon can impede reception. You may acquire satellites faster if you turn the unit off, then power back on. Be sure the batteries are fully charged.

Reading Coordinates
To simplify map navigation, a system of coordinates is used. Coordinates divide the map into a grid and identify a particular location by listing its relative position north/south and east/west. To choose a coordinate system, simply go to the Preferences screen. The most common coordinate systems used in GPS navigation is UTM (Universal Transverse Mercator). It divides the map into a square grid with the grid lines all 1,000 meters apart. Most topo maps have UTM grid lines printed on them. The system is metric-based and requires no conversion of minutes and seconds.

Example: UTM 35N 262893E, 4466396N (the courtyard of Vatopedi Monastery!)
Here, “35N” identifies the map zone, “262893” is the east/west or “easting” number, while “4466396” is the north/south or “northing” number.
Your GPS receiver can automatically display whichever coordinate system you select.

Navigation Skills Plotting a route with waypoints is easy. Simply press the MARK button (or, on some units, press and hold the ENTER button). If you are marking a waypoint where you stand, you can often do this with the single press of a button. You can also add multiple levels of detail: a name, the coordinates, the elevation and even a short note. This is particularly helpful if you are marking waypoints for the path ahead, perhaps before you leave home.

With waypoints in place, your GPS receiver can guide you from point to point. Use the FIND or GOTO button to identify a particular waypoint target. Then switch to the Compass screen where the GPS receiver will give you a bearing and estimate the distance and time of travel.

Making the Most of Your GPS
Barometric altimeter: All GPS units provide elevation as part of the information gleaned from the satellites. But the advantage of also having a barometric altimeter is that it operates independently of this signal. So if the satellite signal becomes too weak to be reliable, the barometric altimeter can still give you an accurate elevation. And since it measures air pressure, it gives you an idea of approaching weather changes by displaying a chart of barometric trends.

Magnetic compass: The magnetic compass works in a similar manner to a traditional capsule compass. Since you are still carrying the latter compass (and a hard-copy map), the magnetic compass is somewhat redundant. So if you need to conserve the GPS battery life, you could turn off the magnetic compass and just use your capsule compass. This will not affect the navigational functions of the GPS receiver, which rely on satellite signals.

Memory Cards: In addition to having preloaded maps, many GPS units allow you to download more maps using CD-ROM software (available separately). Some GPS receivers give you even greater flexibility by using removable microSD memory cards.

Reception Tips: One of the more common complaints from people who have just purchased their first GPS receiver is that they are having difficulty establishing a good, clear signal. If you experience this, refer to your owner’s manual or consider the following: Fix your receiver to a shoulder strap of your pack to give it a clear view of the sky. If you walk with the GPS unit in your hand, do not swing your arms. This motion can disorient the receiver.

A GPS receiver’s accuracy (and usefulness) is completely dependent on being able to receive clear transmission signals from four or more satellites. If the “view” to the horizon or overhead is obstructed, that reception can be effectively blocked or diminished, making the GPS unit unreliable. If this occurs, you may need to get to higher, open ground. In the meantime, turn off your GPS to conserve battery power.

Batteries: Make sure they are fresh at the start of your trip. And carry spares. Consider turning off nonessential features such as auto-routing and backlighting to conserve battery life.

Accuracy – Commercial grade handheld GPS units are able to obtain coordinates with a horizontal accuracy of approximately ±3 meters if the unit can receive a wide area augmentation system (WAAS) signal (or, in Europe, an EGNOS signal); otherwise, the accuracy is approximately ±10 meters. This type of GPS handheld unit provides elevation data with poor accuracy, unless it has a barometric altimeter. Do not forget that, in addition to the US gps system, there are the Soviet GLONASS and the European GALILEO systems.

Google Earth
It is straightforward to export saved routes to be shown on Google Earth. Users may often be disappointed that their saved tracks do not land accurately on top of those shown in GE. It is helpful to realise that GE consists of photographs from satellites that are oblique to the subject. When these photographs are draped over the height information, and ‘rubber-sheeted’ into the correct geo-referenced position, distortion takes place. The error is with GE, not your gps!

A Cautionary Note:
http://phys.org/news/2010-11-reliance-gps-hippocampus-function-age.html