- FREE ASPRS\CaGIS\GLIS online Seminar (GeoBytes)
- Fri, Jan 30, 2015 12:00 PM - 1:00 PM EST
Abstract: This presentation will cover the relationship of and transformations between the several geometric and vertical geodetic reference frames most commonly used in the United States. These include: The North American Datum of 1927 (NAD 27), the North American Datum of 1983 (NAD 83), the International Terrestrial Reference Frame (ITRF), the World Geodetic System of 1984 (WGS 84), the National Geodetic Vertical Datum of 1929 (NGVD 29) and the North American Vertical Datum of 1988 (NAVD). The program will specifically examine tools such as the gridded utilities NADCON and VERTCON developed by the National Geodetic Survey (NGS), as well as the commonly used 3-parameter abridged Molodensky transformations originally computed by the U.S. Defense Mapping Agency (DMA) and the more rigorous 14-parameter transformations supported by the NGS utility HTDP (Horizontal Time Dependent Positioning).
