Dear Gbenga Oduntan and Colleagues,

The International court does not have a good record of using maps and
coordinates to define international boundaries. The major fault being the
exclusion of a standard geodetic datum to define the map and coordinate
system.

Here is my brief summary of how boundaries should be defined so as not to be
ambiguous and are easily re-locatable:

There are two types of boundaries:

1) Natural ­ Such as a coastline, center of a river, highest peaks of a
mountain range, etc. These boundaries are unambiguous and can even move as
long as the movement is gradual, natural, and imperceptible. Coastal land
reclamation may influence an offshore international boundary (say along a
narrow straight, e.g. Singapore and Malaysia,) when this occurs it is best
that the adjoining countries negotiate the boundary location before
construction begins and accurately position boundary points by determining
Latitude and Longitude to a precision of one thousandth of a second of arc
by modern geodetic measurements and computations (nowadays by precise GPS or
similar satellite observations) and referenced to a standard geodetic system
such as the World Geodetic System of 1984 (WGS84) or International
Terrestrial Reference Frame for a given year (e.g. ITRF2000, this system is
usually updated annually due to the four-dimensional nature of precise
geodetic datums.)

2) Artificial ­ An artificial line over the surface of the earth created by
humans to delineate sovereignty between countries. These lines are best
located by agreement between the adjoining countries and located by
artificial monuments or markers with official representation from each
country. These monuments should be accurately positioned (using Latitude and
Longitude to a precision of one thousandth of a second of arc) by modern
geodetic means (nowadays by precise GPS or similar satellite observations)
and referenced to a standard geodetic system such as the World Geodetic
System of 1984 (WGS84) or International Terrestrial Reference Frame for a
given year (e.g. ITRF2000, this system is usually updated annually due to
the four-dimensional nature of precise geodetic datums.) When re-locating
artificial boundaries the monuments take precedence over the coordinates.
Coordinates are used when monuments are destroyed or obliterated. Monuments
disappear usually as a result of theft, destruction, or due to the ravages
of time and lack of maintenance.

The legal precedence is that natural boundaries have priority over
artificial boundaries; and monuments on the ground have priority over
measurements or coordinates (the derivative of measurements.)

When boundaries are in dispute it becomes a matter of law to determine the
true location of the boundary or the extent of sovereignty of each country
involved in the dispute. As in most litigation the international court takes
into account the evidence presented by both sides. Most disputes are over
artificial boundaries where the best evidence may be contained in historical
records of treaties, agreements, declarations, decrees, historic boundary
surveys, maps and all manner of evidence each side can conjure up. Once the
international court determines the true location of the boundary it should
be accurately positioned and monumented on the ground with monument
locations accurately represented by Latitude and Longitude in a standard
geodetic reference datum as described above.

A note on maps and map scale: International boundary maps are usually
depicted at very small scales that cover large areas. The standard line
width on any map is 0.5 millimeters. At a typical scale of 1:5,000,000 the
boundary represented by a line 0.5 millimeters wide would be 2.5 kilometers
wide on the ground. Thus, if the boundary is accurately located and drawn on
the map during the maps construction (often not the case,) using the map as
a means of relocating the boundary would give you a leeway of 2.5 kilometers
on the ground, which is hardly an accurate method of boundary re-location.
If the map has no geodetic datum this leeway can be greater by a factor of
ten or more, which is 25 kilometers more or less on the ground.

A note on Latitude and Longitude: Latitude and Longitude are measurements of
arc from the equator and the Greenwich meridian respectively. Latitude and
longitude are usually expressed in degrees, minutes, and seconds (360
degrees in a circle, 60 minutes in a degree, and 60 seconds in a minute.) At
most inhabited latitudes one second of arc represents about 30 meters on the
ground, hence my recommendation to publish Latitude and Longitude
coordinates to a thousandth of a second of arc which approximates 3
centimeters on the ground. To obtain these levels of precision, a geodetic
version of GPS position receiver operated by a licensed surveyor or
geodesist is required.

I hope this helps.

Dr. Gary Jeffress, Registered Professional Land Surveyor (Texas)
Professor of Geographic Information Science
Department of Computing and Mathematical Sciences
Director, Division of Nearshore Research
Texas A&M University-Corpus Christi
6300 Ocean Drive, Corpus Christi, Texas 78412
Phone 361-825-2720
Fax 361-825-5848