\section{LTP}\label{LTP}
The Local Tangent Plane (LTP) is an approximation of the earth at a fixed position. It is defined using an ECEF position, a LLA position and a rotational matrix to convert between them. \emph{Please note that the matrix transforms from ECEF to ENU!}
\begin{verbatim}
LtpDef   = {      ecef      lla      ltp_of_ecef     }
\end{verbatim}
It is available for the following simple types:\\
\begin{tabular}{c|cccc}
sinmple type & struct name & $p_{ECEF}$ & $p_{LLA}$ & $\mat R_{ltp\_of\_ecef}$\\  \hline 
int32\_t & LtpDef\_i & EcefCoor\_i  ecef & LlaCoor\_i   lla & INT32Mat33 ltp\_of\_ecef\\
float & LtpDef\_f & EcefCoor\_f  ecef & LlaCoor\_f   lla & FloatMat33 ltp\_of\_ecef\\
double & LtpDef\_d & EcefCoor\_d  ecef & LlaCoor\_d   lla & DoubleMat33 ltp\_of\_ecef 
\end{tabular} 
The fixed-point struct has hmsl (height above mean sea level) as an additional parameter.

\subsection{Transformations to LTP}
\subsubsection*{from ECEF}
\input{transformations/ecef2ltp}