TimeDelay.h

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/*
*  Copyright (C) 2007 Alexander Dietz, Drew Keppel, Duncan Brown, David Chin, Jolien Creighton, Kipp Cannon, Stephen Fairhurst
*
*  This program is free software; you can redistribute it and/or modify
*  it under the terms of the GNU General Public License as published by
*  the Free Software Foundation; either version 2 of the License, or
*  (at your option) any later version.
*
*  This program 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 General Public License for more details.
*
*  You should have received a copy of the GNU General Public License
*  along with with program; see the file COPYING. If not, write to the
*  Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston,
*  MA  02111-1307  USA
*/

/*
<lalVerbatim file="TimeDelayHV">

Author: David Chin <dwchin@umich.edu> 1-734-709-9119
$Id: TimeDelay.h,v 1.21 2007/07/11 16:42:11 jolien Exp $
   
</lalVerbatim> */

/* 
<lalLaTeX>

\section{Header \texttt{TimeDelay.h}}
\label{s:TimeDelay.h}

Provides routine to compute time delay between two detectors.

\subsection*{Synopsis}
\begin{verbatim}
#include <lal/TimeDelay.h>
\end{verbatim}

This header provides prototypes of routines to compute the difference in
time for a signal to arrive at two detectors.  The routine is a direct
translation of the Maple worksheet by Anderson, \emph{et al.}, available at
\verb+http://dirac.utb.edu/~warren/unprot/beam_patterns.tar.gz+.

</lalLaTeX> */


#ifndef _TIMEDELAY_H
#define _TIMEDELAY_H

#include <lal/LALStdlib.h>
#include <lal/Date.h>
#include <lal/DetectorSite.h>
#include <lal/SkyCoordinates.h>

#ifdef __cplusplus
extern "C"
{
#endif

NRCSID( TIMEDELAYH, "$Id: TimeDelay.h,v 1.21 2007/07/11 16:42:11 jolien Exp $" );

/* <lalLaTeX>

\subsection*{Error conditions}

</lalLaTeX> */

/* <lalErrTable> */
#define TIMEDELAYH_ENUL 1

#define TIMEDELAYH_MSGENUL "Unexpected null pointer in arguments"
/* </lalErrTable> */

/* <lalLaTeX>

\subsection*{Structures}
\begin{verbatim}
TwoDetsTimeAndASource
\end{verbatim}
\idx[Type]{TwoDetsTimeAndASource}

\noindent This structure stores two pointers to \verb+LALPlaceAndGPS+
structures, and a pointer to a \verb+SkyPosition+ structure.  The
fields are:

\begin{description}
\item{\verb+LALPlaceAndGPS *p_det_and_time1+} The first detector and GPS
\item{\verb+LALPlaceAndGPS *p_det_and_time2+} The second detector and GPS
\item{\verb+SkyPosition *p_source+} The source location (equatorial
    co\"{o}dinates in decimal radians)
\end{description}

</lalLaTeX> */

typedef struct
tagTwoDetsTimeAndASource
{
  LALPlaceAndGPS *p_det_and_time1; /* the first detector and detection time */
  LALPlaceAndGPS *p_det_and_time2; /* the second detector and detection time */
  SkyPosition    *p_source;        /* source Equatorial location
                                    * (lon=RA, lat=dec) in decimal
                                    * radians */ 
}
TwoDetsTimeAndASource;


/* <lalLaTeX>

\begin{verbatim}
DetTimeAndASource
\end{verbatim}
\idx[Type]{DetTimeAndASource}

\noindent This structure stores one pointer to a \verb+LALPlaceAndGPS+
structure, and a pointer to a \verb+SkyPosition+ structure.  The
fields are:

\begin{description}
\item{\verb+LALPlaceAndGPS *p_det_and_time+} The detector and GPS
\item{\verb+SkyPosition *p_source+}  The source location (equatorial
    co\"{o}dinates in decimal radians)
\end{description}

</lalLaTeX> */
  
typedef struct
tagDetTimeAndASource
{
  LALPlaceAndGPS *p_det_and_time; /* detector and detection time */
  SkyPosition    *p_source;       /* source Equatorial location
                                   * (lon=RA, lat=dec) in decimal
                                   * radians */ 
}
DetTimeAndASource;
    

/* <lalLaTeX>
\vfill{\footnotesize\input{TimeDelayHV}}
</lalLaTeX> */

/*
 * Function prototypes
 */

/* <lalLaTeX>
\newpage\input{TimeDelayC}
</lalLaTeX> */

double
XLALArrivalTimeDiff(
        const double detector1_earthfixed_xyz_metres[3],
        const double detector2_earthfixed_xyz_metres[3],
        const double source_right_ascension_radians,
        const double source_declination_radians,
        const LIGOTimeGPS *gpstime
);

void
LALTimeDelay( LALStatus                   *status,
              REAL8                       *p_delay,
              const TwoDetsTimeAndASource *p_two_detectors_time_and_source );

INT8
XLALLightTravelTime ( const LALDetector *aDet,
                      const LALDetector *bDet 
                     );


REAL8
XLALTimeDelayFromEarthCenter(
        const double detector_earthfixed_xyz_metres[3],
        double source_right_ascension_radians,
        double source_declination_radians,
        const LIGOTimeGPS *gpstime
);

void
LALTimeDelayFromEarthCenter( LALStatus               *status,
                             REAL8                   *p_delay,
                             const DetTimeAndASource *p_det_time_and_source );

#ifdef __cplusplus
}
#endif

#endif /* !defined _TIMEDELAY_H */

---