These were my coordinates: N53.581511 E9.604638
According to DJI I was nearby an authorization zone (small aiport nearby as I figured), not NF zone.
In fact the location is also a part of DJI's warning zone around Hamburg International Airport.
In Germany the NF zone is defined as a distance of 0.9 miles from the fence of international airports.
Don't know FAA rules but it makes sense that NF zones have complex shapes and not being circles due to layout of airports.
Max, thanks for the reply...
This further supports my suspicion that DJI simplifies the NF zone by defining a box with the corners representing the furthest extent of the NF zone. When I look at the Class D airspace around the Hamburg Airport it's a complex shape but I looked at the North, South, East and West most points and here's what I get:
North most point = N53 49' 30.01", E9 54' 59.16"
South most point = N53 24' 08.43", E9 41' 33.72"
East most point = N53 42' 32.08", E10 15' 52.88"
West most point = N53 29' 09.94", E9 34' 56.51"
So, I think what DJI is doing is creating a box with a NW corner at N53 49' 30.01", E9 34' 56.51", and the SE corner at N53 24' 08.32", E10 15' 52.88". With that as the coordinates in the DJI database then your location, which is outside of any no fly zone, is put within the box defined by DJI.
Here's the Class D NFZ I think DJI has around the Hamburg Airport. I think the NFZ within the DJI database is the larger box defined by the furthest extent in any direction. That is, anywhere in the box is not permitted because DJI chose to use a simplified box to save space.
Brian