Beginning with PDF 1.6, the size of the default user space unit may be set with the UserUnit entry of the page dictionary. Acrobat 7.0 supports a maximum UserUnit value of 75,000, which gives a maximum page dimension of 15,000,000 inches (14,400 * 75,000 * 1 ⁄ 72). The minimum UserUnit value is 1.0 (the default).
15 million inches happens to be exactly 381 km Source
Remark: The side length of the square correspods to 381 km, subsequently, its area is 145161 km^2 .
381 km^2 are slightly smaller than the city of Cologne.
Some questions…
That’s sooooo arbitrary.
True. But thankfully most of the world uses centimetrs instead of inches nowadays. 😉
To satisfy the anything but metric postulate: 381 km originally are 15 million inches.
However, using some tricks, the size isn’t limited to that.
https://alexwlchan.net/2024/big-pdf/
Remark: The side length of the square correspods to 381 km, subsequently, its area is 145161 km^2 .
381 km^2 are slightly smaller than the city of Cologne.
Good to see Germany won’t run out of PDF for their digital mapping efforts and need a costly replacement.
I’m pretty sure, we would use a costly alternative anyways.