We recently had a thread about how surveyors work and whether they accounted for the curvature of the Earth in larger surveys. The technique of allowing for the curvature is called “geodetic”. This article is about the highly classified team assembled by the Allied forces to search captured German towns for maps and other geographical information. Very similar to the teams that reclaimed Nazi artwork. Their largest haul of material was 250 tons of maps and equipment removed from the German city of Saalfeld one day before the Soviets were given possession. The entire archive of the German military.
I have a fundamental understanding of surveying and have explained a few times to people how surveyors build a long “ladder” of triangles as they march across the country. This allows them to keep on course and by referencing to other ladders they can check and correct each other. A beautiful example of such a network is shown in the photograph of a geodetic survey of Europe. The chart in the photo is titled the “Central European Net” and is the third photo in the story. Note that the photo is subtitled “Before the second adjustment of the loop closures”. Each adjustment makes the whole map more accurate.
After the war the team assembled all of Europe in a vast geodetic grid with help from the German cartographers. It gave them precise targeting data for the entire region. Looking back one man explained, “It was like GPS - before GPS”.
Well worth the short read:
Dennis