The "lines on the (digital) maps" are generally sourced from official public records and have the correct GPS (or local grid) coords.
The images themselves originate from digital capture behind lenses and are subject to subtle stretching and distortion in addition to positional errors in camera position.
It's common to see major visual parts of any "corrected" frame line up exactly with ground reference coords but other parts of the same frame to off by a few metres due to rough and ready "mostly linear" correction that doesn't account well for the digital terrain model the image must draped across (in addition to lens corrections).
Point being - while digital maps can often have alignment errors twixt image pixels and GIS vectors the actual on the ground land surveying by professionals is done using high grade GPS units in addition to truthing from existing monuments using triangulation.
Staking pegs based on looking at a digital map isn't something a professional would normally do as they'd be aware of the various errors (and others) I raised.
The "lines on the (digital) maps" are generally sourced from official public records and have the correct GPS (or local grid) coords.
The images themselves originate from digital capture behind lenses and are subject to subtle stretching and distortion in addition to positional errors in camera position.
It's common to see major visual parts of any "corrected" frame line up exactly with ground reference coords but other parts of the same frame to off by a few metres due to rough and ready "mostly linear" correction that doesn't account well for the digital terrain model the image must draped across (in addition to lens corrections).
Point being - while digital maps can often have alignment errors twixt image pixels and GIS vectors the actual on the ground land surveying by professionals is done using high grade GPS units in addition to truthing from existing monuments using triangulation.
Staking pegs based on looking at a digital map isn't something a professional would normally do as they'd be aware of the various errors (and others) I raised.