Which reference frame is recognized as the international standard?

The international standard reference frame is the World Geodetic System 1984, commonly known as WGS84. WGS84 is a global reference system used for geospatial data and is widely adopted for applications such as GPS and mapping. It provides a consistent framework for geographic coordinate systems and is fundamental for interoperability in global positioning and GIS applications.

While ITRF 2000 (International Terrestrial Reference Frame) is a precise geodetic reference frame that provides coordinates based on observations from GNSS (Global Navigation Satellite Systems) used primarily in scientific applications, it is not as commonly recognized or utilized for everyday mapping and navigation purposes compared to WGS84.

NAD83 (North American Datum 1983) and NAVD88 (North American Vertical Datum 1988) are regional reference systems specifically designed for North American applications and do not have the global authority or reach that WGS84 enjoys. Hence, WGS84 serves as the standard for various international applications, making it the preferred answer in this context.