Using converted WW1 Army Grid Referencing Systems to identify locations where Australian soldiers fell Europe

ABSTRACT Topographic maps (1:40,000) used by the British Army on the Western Front in World War 1 had a five-part Grid Reference System consisting of: (1) Map Number; (2) Letter-Square – 24 letter squaresA to X on each map; (3) Number-Square – 36 (and sometimes 30) 1000-yard squares in each letter square; (4) Minor-Square – four 500-yard squares denoted a, b, c, d in each number square; (5) Small-Square – 10 × 10 = 100 small-squares in a minor-square. Letter and number grid Woesten references (e.g. X: 28.A.6.b.73) cannot be used by modern GPS navigation devices that require geographical coordinates (latitude and longitude) or current map grid coordinates. This paper provides the background behind this project and demonstrates a method of transforming WW1 grid references to Universal Transverse Mercator (UTM) grid coordinates using Google Maps to obtain geographical coordinates, Geographic to UTM grid conversion and a 2D Conformal transformation. As well, it provides a ‘snapshot’ of practical methods that were used to develop a software package that would allow amateur military historians to convert the WW1 Grid Reference System to contemporary coordinates.