Grundbogen
Grundbogen is a German compound noun formed from Grund (foundation, base) and Bogen (sheet, arc, bow). As a common-language term it denotes a foundational sheet, template or basic curve and is used across several technical and administrative contexts to signify an underlying form or reference element.
The literal sense combines the ideas of a base and a sheet or arc; figuratively it conveys
In cartography and surveying the term is sometimes used informally to refer to a base map sheet
Grundbogen is not a standardized technical term with a single authoritative definition; its precise meaning depends