How the Overlay Builder
works.
Overlays from archival records: real 1944 military maps, aligned to true coordinates and layered onto today's satellite imagery. Draw on them, connect them to your research, and export what you find.
Real historical maps, not modern ones
Every overlay starts from an actual period military map: GSGS and similar topographic sheets used by the units themselves, not a modern basemap with pins stuck on it. The terrain, place names, and grid references are exactly what the soldiers on the ground were reading at the time.
Georeferenced onto real, modern satellite imagery
A 1944 topographic sheet isn't just scanned and pasted onto the screen. It's precisely aligned to true geographic coordinates, so it drops directly onto today's satellite imagery of the same ground. Toggle between the historical map and the modern aerial view of the exact same location: see what's changed, orient a unit's position against a farmhouse or road that's still there today, or just get your bearings in a landscape that's otherwise unrecognizable eighty years later.
Draw and annotate directly on the map
Trace troop movements, mark positions, draw routes, and label whatever the research calls for, directly on top of the real historical sheet and at the correct real-world location, not a rough approximation.
Connect it to the research
An overlay isn't a standalone drawing. Link it to a soldier's profile or a research project, and tie it into the timeline you're already building alongside their service records, documents, and photographs.
Export exactly what you need
Draw a box around the exact area you want, choose a resolution, and export a real high-resolution image of it. Not a screenshot, and not the whole map when you only needed one corner of it.
Georeferencing has real limits. How precisely a historical sheet lines up with modern satellite imagery depends on the quality of the original scan and how many known reference points it can be matched against. It's accurate enough for real research use, but it's not laser-precise survey data. Where a map's original edges are damaged or a landmark no longer exists, alignment is necessarily an informed approximation, not a guarantee.