// Copyright 2005, 2006 - Morten Nielsen (www.iter.dk)
//
// This file is part of SharpMap.
// SharpMap is free software; you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation; either version 2 of the License, or
// (at your option) any later version.
//
// SharpMap is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Lesser General Public License for more details.
// You should have received a copy of the GNU Lesser General Public License
// along with SharpMap; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
namespace GeoAPI.CoordinateSystems{
/// <summary>
/// A vertical datum of geoid model derived heights, also called GPS-derived heights.
/// These heights are approximations of orthometric heights (H), constructed from the
/// ellipsoidal heights (h) by the use of the given geoid undulation model (N) through
/// the equation: H=h-N.
/// </summary>
public enum DatumType : int
{
/// <summary>
/// Lowest possible value for horizontal datum types
/// </summary>
HD_Min = 1000,
/// <summary>
/// Unspecified horizontal datum type. Horizontal datums with this type should never
/// supply a conversion to WGS84 using Bursa Wolf parameters.
/// </summary>
HD_Other = 1000,
/// <summary>
/// These datums, such as ED50, NAD27 and NAD83, have been designed to support
/// horizontal positions on the ellipsoid as opposed to positions in 3-D space. These datums were designed mainly to support a horizontal component of a position in a domain of limited extent, such as a country, a region or a continent.
/// </summary>
HD_Classic = 1001,
/// <summary>
/// A geocentric datum is a "satellite age" modern geodetic datum mainly of global
/// extent, such as WGS84 (used in GPS), PZ90 (used in GLONASS) and ITRF. These
/// datums were designed to support both a horizontal component of position and
/// a vertical component of position (through ellipsoidal heights). The regional
/// realizations of ITRF, such as ETRF, are also included in this category.
/// </summary>
HD_Geocentric = 1002,
/// <summary>
/// Highest possible value for horizontal datum types.
/// </summary>
HD_Max = 1999,
/// <summary>
/// Lowest possible value for vertical datum types.
/// </summary>
VD_Min = 2000,
/// <summary>
/// Unspecified vertical datum type.
/// </summary>
VD_Other = 2000,
/// <summary>
/// A vertical datum for orthometric heights that are measured along the plumb line.
/// </summary>
VD_Orthometric = 2001,
/// <summary>
/// A vertical datum for ellipsoidal heights that are measured along the normal to
/// the ellipsoid used in the definition of horizontal datum.
/// </summary>
VD_Ellipsoidal = 2002,
/// <summary>
/// The vertical datum of altitudes or heights in the atmosphere. These are
/// approximations of orthometric heights obtained with the help of a barometer or
/// a barometric altimeter. These values are usually expressed in one of the
/// following units: meters, feet, millibars (used to measure pressure levels), or
/// theta value (units used to measure geopotential height).
/// </summary>
VD_AltitudeBarometric = 2003,
/// <summary>
/// A normal height system.
/// </summary>
VD_Normal = 2004,
/// <summary>
/// A vertical datum of geoid model derived heights, also called GPS-derived heights.
/// These heights are approximations of orthometric heights (H), constructed from the
/// ellipsoidal heights (h) by the use of the given geoid undulation model (N)
/// through the equation: H=h-N.
/// </summary>
VD_GeoidModelDerived = 2005,
/// <summary>
/// This attribute is used to support the set of datums generated for hydrographic
/// engineering projects where depth measurements below sea level are needed. It is
/// often called a hydrographic or a marine datum. Depths are measured in the
/// direction perpendicular (approximately) to the actual equipotential surfaces of
/// the earth's gravity field, using such procedures as echo-sounding.
/// </summary>
VD_Depth = 2006,
/// <summary>
/// Highest possible value for vertical datum types.
/// </summary>
VD_Max = 2999,
/// <summary>
/// Lowest possible value for local datum types.
/// </summary>
LD_Min = 10000,
/// <summary>
/// Highest possible value for local datum types.
/// </summary>
LD_Max = 32767
}
}
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