To display altitude above ground, you need to have terrain data loaded in your SkyDrop. We pre-load most flown areas during production. If you have an older device without pre-loaded terrain data, you can download this package here. If your area in not included, you can select and download terrain data and following how to guide. Red marked areas in map represent pre-loaded terrain dat.
SkyDrop vario has airspace violation warning functions. You can download airspace data here.