Which DATUM do we use?

Which DATUM do we use?

• A. WGS-84
• B. NAD27
• C. NAD83
• D. ETRS89

Answer: (A)

Geospatial coordinates are defined by a datum, which sets the shape of the Earth and where your coordinates sit relative to that shape. For modern navigation and military operations, the GPS system provides coordinates in the WGS-84 datum, an Earth-centered, Earth-fixed reference that serves as the global standard. That makes it the default choice for maps, targeting, and geospatial data in the field, ensuring compatibility across devices and systems. The other options are regional or older datums: NAD27 is based on an older ellipsoid and largely obsolete for current GPS work; NAD83 is a North American update that aligns with a different frame rather than GPS’s global standard; ETRS89 is Europe’s regional reference. In practice, you use WGS-84 to align with GPS data and global datasets, unless a specific operation requires a local datum with a proper transformation applied.

Geospatial coordinates are defined by a datum, which sets the shape of the Earth and where your coordinates sit relative to that shape. For modern navigation and military operations, the GPS system provides coordinates in the WGS-84 datum, an Earth-centered, Earth-fixed reference that serves as the global standard. That makes it the default choice for maps, targeting, and geospatial data in the field, ensuring compatibility across devices and systems. The other options are regional or older datums: NAD27 is based on an older ellipsoid and largely obsolete for current GPS work; NAD83 is a North American update that aligns with a different frame rather than GPS’s global standard; ETRS89 is Europe’s regional reference. In practice, you use WGS-84 to align with GPS data and global datasets, unless a specific operation requires a local datum with a proper transformation applied.