\hypertarget{classosgeo_1_1proj_1_1datum_1_1Datum}{}\doxysection{osgeo\+::proj\+::datum\+::Datum Class Reference}
\label{classosgeo_1_1proj_1_1datum_1_1Datum}\index{osgeo::proj::datum::Datum@{osgeo::proj::datum::Datum}}


Abstract class of the relationship of a coordinate system to an object, thus creating a coordinate reference system.  




{\ttfamily \#include $<$datum.\+hpp$>$}



Inheritance diagram for osgeo\+::proj\+::datum\+::Datum\+:
% FIG 0


Collaboration diagram for osgeo\+::proj\+::datum\+::Datum\+:
% FIG 1
\doxysubsection*{Public Member Functions}
\begin{DoxyCompactItemize}
\item 
const \mbox{\hyperlink{classosgeo_1_1proj_1_1util_1_1optional}{util\+::optional}}$<$ std\+::string $>$ \& \mbox{\hyperlink{classosgeo_1_1proj_1_1datum_1_1Datum_afaf2ca13f12a6240cbd009719c9874fd}{anchor\+Definition}} () const
\begin{DoxyCompactList}\small\item\em Return the anchor definition. \end{DoxyCompactList}\item 
const \mbox{\hyperlink{classosgeo_1_1proj_1_1util_1_1optional}{util\+::optional}}$<$ \mbox{\hyperlink{classosgeo_1_1proj_1_1common_1_1DateTime}{common\+::\+Date\+Time}} $>$ \& \mbox{\hyperlink{classosgeo_1_1proj_1_1datum_1_1Datum_a053c9bf2c0be6e28b10efa5433b9d629}{publication\+Date}} () const
\begin{DoxyCompactList}\small\item\em Return the date on which the datum definition was published. \end{DoxyCompactList}\item 
const \mbox{\hyperlink{namespaceosgeo_1_1proj_1_1common_accd81b8802949ca7ecd25579c55cfae2}{common\+::\+Identified\+Object\+Ptr}} \& \mbox{\hyperlink{classosgeo_1_1proj_1_1datum_1_1Datum_a33b60b755c490597baefc4cfa97c17c9}{conventional\+RS}} () const
\begin{DoxyCompactList}\small\item\em Return the conventional reference system. \end{DoxyCompactList}\end{DoxyCompactItemize}
\doxysubsection*{Additional Inherited Members}


\doxysubsection{Detailed Description}
Abstract class of the relationship of a coordinate system to an object, thus creating a coordinate reference system. 

For geodetic and vertical coordinate reference systems, it relates a coordinate system to the Earth (or the celestial body considered). With other types of coordinate reference systems, the datum may relate the coordinate system to another physical or virtual object. A datum uses a parameter or set of parameters that determine the location of the origin of the coordinate reference system. Each datum subtype can be associated with only specific types of coordinate reference systems.

\begin{DoxyRemark}{Remarks}
Implements \mbox{\hyperlink{classosgeo_1_1proj_1_1datum_1_1Datum}{Datum}} from \mbox{\hyperlink{general_doc_ISO_19111_2019}{ISO 19111\+:2019}} 
\end{DoxyRemark}


\doxysubsection{Member Function Documentation}
\mbox{\Hypertarget{classosgeo_1_1proj_1_1datum_1_1Datum_afaf2ca13f12a6240cbd009719c9874fd}\label{classosgeo_1_1proj_1_1datum_1_1Datum_afaf2ca13f12a6240cbd009719c9874fd}} 
\index{osgeo::proj::datum::Datum@{osgeo::proj::datum::Datum}!anchorDefinition@{anchorDefinition}}
\index{anchorDefinition@{anchorDefinition}!osgeo::proj::datum::Datum@{osgeo::proj::datum::Datum}}
\doxysubsubsection{\texorpdfstring{anchorDefinition()}{anchorDefinition()}}
{\footnotesize\ttfamily const \mbox{\hyperlink{classosgeo_1_1proj_1_1util_1_1optional}{util\+::optional}}$<$ std\+::string $>$ \& osgeo\+::proj\+::datum\+::\+Datum\+::anchor\+Definition (\begin{DoxyParamCaption}{ }\end{DoxyParamCaption}) const}



Return the anchor definition. 

A description -\/ possibly including coordinates of an identified point or points -\/ of the relationship used to anchor a coordinate system to the Earth or alternate object. 
\begin{DoxyItemize}
\item For modern geodetic reference frames the anchor may be a set of station coordinates; if the reference frame is dynamic it will also include coordinate velocities. For a traditional geodetic datum, this anchor may be a point known as the fundamental point, which is traditionally the point where the relationship between geoid and ellipsoid is defined, together with a direction from that point. 
\item For a vertical reference frame the anchor may be the zero level at one or more defined locations or a conventionally defined surface. 
\item For an engineering datum, the anchor may be an identified physical point with the orientation defined relative to the object. 
\end{DoxyItemize}

\begin{DoxyReturn}{Returns}
the anchor definition, or empty. 
\end{DoxyReturn}
\mbox{\Hypertarget{classosgeo_1_1proj_1_1datum_1_1Datum_a33b60b755c490597baefc4cfa97c17c9}\label{classosgeo_1_1proj_1_1datum_1_1Datum_a33b60b755c490597baefc4cfa97c17c9}} 
\index{osgeo::proj::datum::Datum@{osgeo::proj::datum::Datum}!conventionalRS@{conventionalRS}}
\index{conventionalRS@{conventionalRS}!osgeo::proj::datum::Datum@{osgeo::proj::datum::Datum}}
\doxysubsubsection{\texorpdfstring{conventionalRS()}{conventionalRS()}}
{\footnotesize\ttfamily const \mbox{\hyperlink{namespaceosgeo_1_1proj_1_1common_accd81b8802949ca7ecd25579c55cfae2}{common\+::\+Identified\+Object\+Ptr}} \& osgeo\+::proj\+::datum\+::\+Datum\+::conventional\+RS (\begin{DoxyParamCaption}{ }\end{DoxyParamCaption}) const}



Return the conventional reference system. 

This is the name, identifier, alias and remarks for the terrestrial reference system or vertical reference system realized by this reference frame, for example \char`\"{}\+ITRS\char`\"{} for ITRF88 through ITRF2008 and ITRF2014, or \char`\"{}\+EVRS\char`\"{} for EVRF2000 and EVRF2007.

\begin{DoxyReturn}{Returns}
the conventional reference system, or nullptr. 
\end{DoxyReturn}
\mbox{\Hypertarget{classosgeo_1_1proj_1_1datum_1_1Datum_a053c9bf2c0be6e28b10efa5433b9d629}\label{classosgeo_1_1proj_1_1datum_1_1Datum_a053c9bf2c0be6e28b10efa5433b9d629}} 
\index{osgeo::proj::datum::Datum@{osgeo::proj::datum::Datum}!publicationDate@{publicationDate}}
\index{publicationDate@{publicationDate}!osgeo::proj::datum::Datum@{osgeo::proj::datum::Datum}}
\doxysubsubsection{\texorpdfstring{publicationDate()}{publicationDate()}}
{\footnotesize\ttfamily const \mbox{\hyperlink{classosgeo_1_1proj_1_1util_1_1optional}{util\+::optional}}$<$ \mbox{\hyperlink{classosgeo_1_1proj_1_1common_1_1DateTime}{common\+::\+Date\+Time}} $>$ \& osgeo\+::proj\+::datum\+::\+Datum\+::publication\+Date (\begin{DoxyParamCaption}{ }\end{DoxyParamCaption}) const}



Return the date on which the datum definition was published. 

\begin{DoxyNote}{Note}
Departure from \mbox{\hyperlink{general_doc_ISO_19111_2019}{ISO 19111\+:2019}} \+: we return a Date\+Time instead of a Citation\+::\+Date.
\end{DoxyNote}
\begin{DoxyReturn}{Returns}
the publication date, or empty. 
\end{DoxyReturn}


The documentation for this class was generated from the following files\+:\begin{DoxyCompactItemize}
\item 
include/proj/datum.\+hpp\item 
src/iso19111/datum.\+cpp\end{DoxyCompactItemize}
