I previously have visited the National Library of Scotland website to investigate the work done overlaying British WWI field maps onto modern maps.
This work is oblique to my work because the work here is about British troops, and is only getting WWI maps more accessible to the public. I was unable to discover any information about the projection problem.
Search: World War one British map projections
Results:
The first result yielded this result:
Coordinate Transformations for World War 1 Topographic Maps. R.E. Deakin; BONBEACH, VIC, 3196, Australia. Email: randm.deakin@gmail.com . 25-Mar-2015. Presented at the Victorian Regional Survey Conference: From the Bush to the Battlefield, Wangaratta, 17-19 April 2015.
The next relevant result yielded this result "The Muninn Project: Converting British Trench Map Coordinates. Written by Dr. Rob Warren, Peng; email: warren@dbdump.org; Adjunct Professor, Carleton University, Mathematics and Statistics.
I have made contact by email as his current research area is parallel to mine.
Here two extracts are interesting:
"Because longitude and latitude were not really workable for tactical military communications, a grid was superimposed over the 1:40,000 maps. For reasons that are lost in the annals of inter-branch miscommunications the map grid was itself based on yards instead of the maps sheet lines that were in meters. Of course, meters and yards are slightly different and thus the grid does not align with the distance from the origin in meters, making the determination of the modern day longitude and latitude painful. Because the grid spills over the edges of the map, it is possible to have two sets of Trench Map coordinates refer to the same place. This no doubt sent more than one officer cursing trying to find locations at the edges of his map."
The second and most useful for the immediate Technical Log task #11 is this extract:
"The actual projection of the maps was the Belgian (and in some French maps) Bonne projection. The Ellipsoid, or the specific size and shape of the planet, used was the Delambre one from 1810. The origin at Brussels is a point of contention; different publications report different locations. Another reports the origin as being the old Brussels observatory which unfortunately moved several times. Both the position recorded by [1] as 50°25'0.0006", 4°22'12.6978" and [2] as 51°10'06.895", 4°22'05.89" both of which are a few kilometer off. After a bit of help from the Nationaal Geografisch Instituut and the triangulation from [3], the actual origin of the map as 50°24', 4°22'5.89", which give results that are reasonable."
This effectively concludes the first steps in this proof of concept process. However the process now needs to be completed in QGIS! ...
I previously have visited the National Library of Scotland website to investigate the work done overlaying British WWI field maps onto modern maps. This work is oblique to my work because the work here is about British troops, and is only getting WWI maps more accessible to the public. I was unable to discover any information about the projection problem.
Google Searches
Search: british mapping - ordinance department Results: https://www.ordnancesurvey.co.uk https://www.ordnancesurvey.co.uk/resources/maps-and-geographic-resources/index.html https://www.ordnancesurvey.co.uk/international/knowledge/index.html https://www.ordnancesurvey.co.uk/international/knowledge/data-collection-management.html
Conclusions: This search did not help me.
Search: World War one British map projections Results:
The first result yielded this result: Coordinate Transformations for World War 1 Topographic Maps. R.E. Deakin; BONBEACH, VIC, 3196, Australia. Email: randm.deakin@gmail.com . 25-Mar-2015. Presented at the Victorian Regional Survey Conference: From the Bush to the Battlefield, Wangaratta, 17-19 April 2015.
The next relevant result yielded this result "The Muninn Project: Converting British Trench Map Coordinates. Written by Dr. Rob Warren, Peng; email: warren@dbdump.org; Adjunct Professor, Carleton University, Mathematics and Statistics.
I have made contact by email as his current research area is parallel to mine.
Here two extracts are interesting: "Because longitude and latitude were not really workable for tactical military communications, a grid was superimposed over the 1:40,000 maps. For reasons that are lost in the annals of inter-branch miscommunications the map grid was itself based on yards instead of the maps sheet lines that were in meters. Of course, meters and yards are slightly different and thus the grid does not align with the distance from the origin in meters, making the determination of the modern day longitude and latitude painful. Because the grid spills over the edges of the map, it is possible to have two sets of Trench Map coordinates refer to the same place. This no doubt sent more than one officer cursing trying to find locations at the edges of his map."
The second and most useful for the immediate Technical Log task #11 is this extract: "The actual projection of the maps was the Belgian (and in some French maps) Bonne projection. The Ellipsoid, or the specific size and shape of the planet, used was the Delambre one from 1810. The origin at Brussels is a point of contention; different publications report different locations. Another reports the origin as being the old Brussels observatory which unfortunately moved several times. Both the position recorded by [1] as 50°25'0.0006", 4°22'12.6978" and [2] as 51°10'06.895", 4°22'05.89" both of which are a few kilometer off. After a bit of help from the Nationaal Geografisch Instituut and the triangulation from [3], the actual origin of the map as 50°24', 4°22'5.89", which give results that are reasonable."
This effectively concludes the first steps in this proof of concept process. However the process now needs to be completed in QGIS! ...