Jump to content
Free downloads from TNA ×
The Great War (1914-1918) Forum

Remembered Today:

Location


Luca1969

Recommended Posts

Hello,

 

I am trying to locate a field cemetery that should be in the area of Saint Pierre Aigle, Aisne. It was theatre of operations of the AEF second division on July 18, 1918 and I have the coordinates in the american documents which I cannot translate into longitude, latitude meaningful numbers.

 

This is what I have: E 288.9, N 171.4

 

Can someone help?

 

Luca

Link to comment
Share on other sites

I will have a better look for a map tomorrow but as Saint Pierre Aigle is South West of Soissons, I think the map reference will be the other way round, E 171.4 N 288.9.

These values are a Lambert grid reference but sadly the Lambert grid currently in use in France does not match the one used in the great War, even French cartographers puzzle over the exact parameters of the older grid.

 

Howard

 

Link to comment
Share on other sites

Thank you Howard, I am definitely not an expert in cartography.

 

Following your thread I have found an article on JStore (The Evolution of Military Grids, by Jakob Skop) which defines the Lambert grid used in ww1. According to the article, in developing the Lambert grid the "new" origin was put 55 grades North and 6 degree East of Paris at coordinates 49° 30' N, 7° 44' 13.95" E. To this location was labeled as 500,00 (meter) E 300,00 (meter) N.

 

That sounds like a good starting point. Now, how can we relate the coordinates I have with this origin?

 

L

Link to comment
Share on other sites

I have not found a French map with a Lambert grid that covers the right place but I have this one that is very close. It is SW of Soissons very close to Saint Pierre Aigle and as you can see, the Eastings almost go down to 171, the Northings to almost 289- tantalising!

 

If you fit this map to Google Earth and project a few km south and west you will get the right point. These Lambert squares are 1km each. Large version here.

 

Along with others on the forum I have chased the problem of calculating the GPS locations from Great War map references, with the Brutish ones this has been very successful using the equations from the US paper Map Projections-A Working Manual by John Snyder and adding a small fiddle factor. See tmapper.com.

 

The trouble with the French ones is that part of the data is missing, especially the Figure of the Earth they used so transformations using Snyder’s equations have always come out in error by more than we would like. I think they used a Figure called Nord de Guerre and the origin you mention, so do others, but it still does not work. In British reports published just post war it was pointed out that many French trig co-ordinate tables contained errors, (typos?) so it is very likely that we shall never be able to calculate the transformations with any accuracy. For that reason we are stuck with geo-referencing maps and going from there. I would be happy to do that if I could find one!!!!

 

Howard

Missy.jpg

Link to comment
Share on other sites

I'm not certain this helps but I found a Lambert conversion site sometime ago. See post below.

From memory I think it deals with various inter-war map systems.

TEW

Edited 2nd time. Link to Coordinates Translator Here.

 

 

Edited by TEW
Change Link
Link to comment
Share on other sites

I would be interested to see that.

 

Modern French Lambert grids are split into Zone 1, Zone 2 etc. and are different to Great War maps.

 

I have some 2nd war maps with Lambert co-ordinates, some of these geo-reference using Nord de Guerre, some don't. In the inter war period there was a habit to use old maps with new overlays and some old grids were either not checked or used without thought resulting in some odd errors. I also have some geological maps of France published in 1942-1944 overlaid on maps as early as 1832. Re-survey is a colossal task.

 

I did find a site that converted Lambert to WGS84 but when plotted on a map were some way off, near(ish) but not spot on.

 

Howard

Link to comment
Share on other sites

Thank you so much, I realised that American maps had the quadrants. I checked the second division attack on July 18, 1918 and found the exact location I was looking for.

The Texas University has a collection of the summary of operations and maps publicly available, in this case this one:

 

txu-pclmaps-oclc-6205448-2d-division-ais

 

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...