| Title | Towards the unification of the vertical datum over the North American continent |
| Author | Smith, D; Véronneau, M; Roman, D; Huang, J L; Wang, Y M; Sideris, M |
| Source | Reference Frames for Applications in Geosciences, proceedings of the symposium; by Altamimi, Z (ed.); Collilieux, X (ed.); International Association of Geodesy Symposia vol. 138, 2013 p. 253-258, https://doi.org/10.1007/978-3-642-32998-2 36 |
| Year | 2013 |
| Alt Series | Natural Resources Canada, Contribution Series 20170012 |
| Publisher | Springer Berlin Heidelberg |
| Meeting | International Association of Geodesy Symposium, Reference Frames for Applications in Geosciences (REFAG2010); Marne-La-Vallée; FR; October 4-8, 2010 |
| Document | serial |
| Lang. | English |
| Media | on-line; digital |
| File format | pdf |
| Province | Canada; Offshore region; British Columbia; Alberta; Saskatchewan; Manitoba; Ontario; Quebec; New Brunswick; Nova Scotia; Prince Edward Island; Newfoundland and Labrador; Northwest Territories; Yukon;
Nunavut |
| NTS | 1; 2; 3; 10; 11; 12; 13; 14; 15; 16; 20; 21; 22; 23; 24; 25; 26; 27; 28; 29; 30; 31; 32; 33; 34; 35; 36; 37; 38; 39; 40; 41; 42; 43; 44; 45; 46; 47; 48; 49; 52; 53; 54; 55; 56; 57; 58; 59; 62; 63; 64; 65;
66; 67; 68; 69; 72; 73; 74; 75; 76; 77; 78; 79; 82; 83; 84; 85; 86; 87; 88; 89; 92; 93; 94; 95; 96; 97; 98; 99; 102; 103; 104; 105; 106; 107; 114O; 114P; 115; 116; 117; 120; 340; 560 |
| Area | North America; Caribbean; Hawaii; Central America; Canada; United States of America; Mexico |
| Lat/Long WENS | -141.0000 -50.0000 90.0000 41.7500 |
| Lat/Long WENS | -126.0000 -68.0000 48.0000 24.0000 |
| Subjects | geophysics; geodesy; crustal movements; crustal uplift; subsidence; gravity field; isostasy; isostatic rebound; earthquakes; sea level changes; vertical datums; geoid; global navigation satellite
systems (GNSS) |
| Illustrations | sketch maps |
| Released | 2012 11 27 |
| Abstract | (Summary)
The United Sates adopted the North American Vertical Datum of 1988 (NAVD 88) for its official vertical datum in the 1990s. Canada has been using the Canadian Geodetic Vertical Datum
(CGVD28) for its height applications since the 1930s. The use of the different datums causes inconsistent heights across the border between the two countries, and the topographic height data from the two countries are not compatible. Both datums rely
on passive control and significant pre-modern survey data, yielding not only misalignment of the datums to the best known global geoid at approximately 1-2 meters, but also local uplift and subsidence issues which may significantly exceed 1-2 meters
in extreme cases.
Today, the GNSS provides the geometric (ellipsoidal) height to an accuracy of 1-2 centimeters globally. Because of this, users have begun to demand a physical height system that is closely related to the Earth's gravity field to
a comparable accuracy. To address this need, government agencies of both countries are preparing the next generation of vertical datums. Even if the new datums are based on the same concepts and parameters, it is possible to have inconsistent heights
along the borders due to the differences in the realization of the datums. To avoid inconsistency, it is in the interest of both countries to have a united, seamless, highly accurate vertical datum. The proposed replacements for CGVD28 and NAVD88
shall be based on GNSS positioning and a high accuracy gravimetric geoid that covers the territories of the United States, Canada, Mexico and the surrounding waters (to include all of Alaska, Hawaii, the Caribbean and Central America). To account for
the effect of the sea level change, postglacial rebound, earthquakes and subsidence, this datum will also provide information on these changes. Detailed description of the definition, realization and maintenance of the datum is proposed. The
challenges in realization and maintaining the datum are also discussed. |
| GEOSCAN ID | 300310 |
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