-/**************************************************************************
- * fg_geodesy.c -- routines to convert between geodetic and geocentric
- * coordinate systems.
- *
- * Copied and adapted directly from LaRCsim/ls_geodesy.c
- *
- * See below for the complete original LaRCsim comments.
- *
- * $Id$
- * (Log is kept at end of this file)
- **************************************************************************/
+// fg_geodesy.cxx -- routines to convert between geodetic and geocentric
+// coordinate systems.
+//
+// Copied and adapted directly from LaRCsim/ls_geodesy.c
+//
+// See below for the complete original LaRCsim comments.
+//
+// $Id$
+// (Log is kept at end of this file)
#include <math.h>
+#include <errno.h>
-#include <Math/fg_geodesy.h>
#include <Include/fg_constants.h>
+#include <Math/fg_geodesy.hxx>
+#include <Math/point3d.hxx>
-/* ONE_SECOND is pi/180/60/60, or about 100 feet at earths' equator */
+// ONE_SECOND is pi/180/60/60, or about 100 feet at earths' equator
#define ONE_SECOND 4.848136811E-6
-/* fgGeocToGeod(lat_geoc, radius, *lat_geod, *alt, *sea_level_r)
- * INPUTS:
- * lat_geoc Geocentric latitude, radians, + = North
- * radius C.G. radius to earth center (meters)
- *
- * OUTPUTS:
- * lat_geod Geodetic latitude, radians, + = North
- * alt C.G. altitude above mean sea level (meters)
- * sea_level_r radius from earth center to sea level at
- * local vertical (surface normal) of C.G. (meters)
- */
+// fgGeocToGeod(lat_geoc, radius, *lat_geod, *alt, *sea_level_r)
+// INPUTS:
+// lat_geoc Geocentric latitude, radians, + = North
+// radius C.G. radius to earth center (meters)
+//
+// OUTPUTS:
+// lat_geod Geodetic latitude, radians, + = North
+// alt C.G. altitude above mean sea level (meters)
+// sea_level_r radius from earth center to sea level at
+// local vertical (surface normal) of C.G. (meters)
+
void fgGeocToGeod( double lat_geoc, double radius, double
*lat_geod, double *alt, double *sea_level_r )
double t_lat, x_alpha, mu_alpha, delt_mu, r_alpha, l_point, rho_alpha;
double sin_mu_a, denom,delt_lambda, lambda_sl, sin_lambda_sl;
- if( ( (FG_PI_2 - lat_geoc) < ONE_SECOND ) /* near North pole */
- || ( (FG_PI_2 + lat_geoc) < ONE_SECOND ) ) /* near South pole */
+ if( ( (FG_PI_2 - lat_geoc) < ONE_SECOND ) // near North pole
+ || ( (FG_PI_2 + lat_geoc) < ONE_SECOND ) ) // near South pole
{
*lat_geod = lat_geoc;
*sea_level_r = EQUATORIAL_RADIUS_M*E;
} else {
t_lat = tan(lat_geoc);
x_alpha = E*EQUATORIAL_RADIUS_M/sqrt(t_lat*t_lat + E*E);
- mu_alpha = atan2(sqrt(RESQ_M - x_alpha*x_alpha),E*x_alpha);
+ double tmp = RESQ_M - x_alpha * x_alpha;
+ if ( tmp < 0.0 ) { tmp = 0.0; }
+ mu_alpha = atan2(sqrt(tmp),E*x_alpha);
if (lat_geoc < 0) mu_alpha = - mu_alpha;
sin_mu_a = sin(mu_alpha);
delt_lambda = mu_alpha - lat_geoc;
r_alpha = x_alpha/cos(lat_geoc);
l_point = radius - r_alpha;
*alt = l_point*cos(delt_lambda);
+
+ // check for domain error
+ if ( errno == EDOM ) {
+ cout << "Domain ERROR in fgGeocToGeod!!!!\n";
+ *alt = 0.0;
+ }
+
denom = sqrt(1-EPS*EPS*sin_mu_a*sin_mu_a);
rho_alpha = EQUATORIAL_RADIUS_M*(1-EPS)/
(denom*denom*denom);
delt_mu = atan2(l_point*sin(delt_lambda),rho_alpha + *alt);
*lat_geod = mu_alpha - delt_mu;
- lambda_sl = atan( E*E * tan(*lat_geod) ); /* SL geoc. latitude */
+ lambda_sl = atan( E*E * tan(*lat_geod) ); // SL geoc. latitude
sin_lambda_sl = sin( lambda_sl );
*sea_level_r =
sqrt(RESQ_M / (1 + ((1/(E*E))-1)*sin_lambda_sl*sin_lambda_sl));
+
+ // check for domain error
+ if ( errno == EDOM ) {
+ cout << "Domain ERROR in fgGeocToGeod!!!!\n";
+ *sea_level_r = 0.0;
+ }
}
+
}
-/* fgGeodToGeoc( lat_geod, alt, *sl_radius, *lat_geoc )
- * INPUTS:
- * lat_geod Geodetic latitude, radians, + = North
- * alt C.G. altitude above mean sea level (meters)
- *
- * OUTPUTS:
- * sl_radius SEA LEVEL radius to earth center (meters)
- * (add Altitude to get true distance from earth center.
- * lat_geoc Geocentric latitude, radians, + = North
- *
- */
+// fgGeodToGeoc( lat_geod, alt, *sl_radius, *lat_geoc )
+// INPUTS:
+// lat_geod Geodetic latitude, radians, + = North
+// alt C.G. altitude above mean sea level (meters)
+//
+// OUTPUTS:
+// sl_radius SEA LEVEL radius to earth center (meters)
+// (add Altitude to get true distance from earth center.
+// lat_geoc Geocentric latitude, radians, + = North
+//
+
void fgGeodToGeoc( double lat_geod, double alt, double *sl_radius,
double *lat_geoc )
{
double lambda_sl, sin_lambda_sl, cos_lambda_sl, sin_mu, cos_mu, px, py;
- lambda_sl = atan( E*E * tan(lat_geod) ); /* sea level geocentric latitude */
+ lambda_sl = atan( E*E * tan(lat_geod) ); // sea level geocentric latitude
sin_lambda_sl = sin( lambda_sl );
cos_lambda_sl = cos( lambda_sl );
- sin_mu = sin(lat_geod); /* Geodetic (map makers') latitude */
+ sin_mu = sin(lat_geod); // Geodetic (map makers') latitude
cos_mu = cos(lat_geod);
*sl_radius =
sqrt(RESQ_M / (1 + ((1/(E*E))-1)*sin_lambda_sl*sin_lambda_sl));
$Header$
$Log$
+Revision 1.4 1998/11/20 01:00:36 curt
+Patch in fgGeoc2Geod() to avoid a floating explosion.
+point3d.hxx include math.h for FreeBSD
+
+Revision 1.3 1998/11/11 00:18:36 curt
+Check for domain error in fgGeoctoGeod()
+
+Revision 1.2 1998/10/16 23:36:36 curt
+c++-ifying.
+
Revision 1.1 1998/10/16 19:30:40 curt
Renamed .c -> .h so we can start adding c++ supporting routines.
--------------------------------------------------------------------------*/
-/* $Log$
-/* Revision 1.1 1998/10/16 19:30:40 curt
-/* Renamed .c -> .h so we can start adding c++ supporting routines.
-/*
- * Revision 1.6 1998/07/08 14:40:07 curt
- * polar3d.[ch] renamed to polar3d.[ch]xx, vector.[ch] renamed to vector.[ch]xx
- * Updated fg_geodesy comments to reflect that routines expect and produce
- * meters.
- *
- * Revision 1.5 1998/04/25 22:06:23 curt
- * Edited cvs log messages in source files ... bad bad bad!
- *
- * Revision 1.4 1998/01/27 00:47:59 curt
- * Incorporated Paul Bleisch's <pbleisch@acm.org> new debug message
- * system and commandline/config file processing code.
- *
- * Revision 1.3 1998/01/19 19:27:12 curt
- * Merged in make system changes from Bob Kuehne <rpk@sgi.com>
- * This should simplify things tremendously.
- *
- * Revision 1.2 1997/12/15 23:54:54 curt
- * Add xgl wrappers for debugging.
- * Generate terrain normals on the fly.
- *
- * Revision 1.1 1997/07/31 23:13:14 curt
- * Initial revision.
- *
- */
+// $Log$
+// Revision 1.4 1998/11/20 01:00:36 curt
+// Patch in fgGeoc2Geod() to avoid a floating explosion.
+// point3d.hxx include math.h for FreeBSD
+//
+// Revision 1.3 1998/11/11 00:18:36 curt
+// Check for domain error in fgGeoctoGeod()
+//
+// Revision 1.2 1998/10/16 23:36:36 curt
+// c++-ifying.
+//
+// Revision 1.1 1998/10/16 19:30:40 curt
+// Renamed .c -> .h so we can start adding c++ supporting routines.
+//
+// Revision 1.6 1998/07/08 14:40:07 curt
+// polar3d.[ch] renamed to polar3d.[ch]xx, vector.[ch] renamed to vector.[ch]xx
+// Updated fg_geodesy comments to reflect that routines expect and produce
+// meters.
+//
+// Revision 1.5 1998/04/25 22:06:23 curt
+// Edited cvs log messages in source files ... bad bad bad!
+//
+// Revision 1.4 1998/01/27 00:47:59 curt
+// Incorporated Paul Bleisch's <pbleisch@acm.org> new debug message
+// system and commandline/config file processing code.
+//
+// Revision 1.3 1998/01/19 19:27:12 curt
+// Merged in make system changes from Bob Kuehne <rpk@sgi.com>
+// This should simplify things tremendously.
+//
+// Revision 1.2 1997/12/15 23:54:54 curt
+// Add xgl wrappers for debugging.
+// Generate terrain normals on the fly.
+//
+// Revision 1.1 1997/07/31 23:13:14 curt
+// Initial revision.
+//
+
projects / simgear.git / blobdiff