All the maps are equidistant cylindrical projections.
Our JAVA applets use the formulas of the equidistant conic projection (which dates
back to Claudius Ptolemy) with standard parallels which are equidistant from the
Standard parallels : 13.467° N (Phnom Bok) and 13.467° S
The formulas are provided by http://mathworld.wolfram.com/ConicEquidistantProjection.html
The straight lines are loxodromes ie lines of constant bearing. The circles are the
loci of points located at a given number of meters from a centre. We took into account
the World Geodetic System of 1984 (WGS84).
The latter is described by http://home.online.no/~sigurdhu/WGS84_Eng.html .
Our goal was to reproduce the work of an ancient surveyor.
Each depicted temple was digitized in the following way.
An outline in which two features were identified was traced from a satellite image
or from a plan of the “École française d’Extrême Orient” (EFEO). The cartesian coordinates
of the pixel elements of the outline were determined by a computer program “EditJpeg.exe”
(Durham, 2002) and the pairs of coordinates stored in a file. With the help of the
cartesian and geographical coordinates of the two features, the JAVA program calculates
the geographical coordinates of each pixel and depicts them on the cylindrical projection.