BH3XZT I'm not really sure about this either... I recall seeing comments on v2ex where altitude data was mentioned as being classified information.
According to the "Surveying Method," the term "survey" refers to the activities of determining, collecting, describing, and processing data, information, and results related to the shape, size, spatial location, and properties of natural geographical elements or surface artificial facilities.
I think this range is a bit too wide…
During development, I have seen... National Geographic Public Service Platform Perhaps it would be best to contact a professional here.
You can also get advice here. Ministry of Natural Resources - Summary of Responses