ossimHgtRef Class Reference

#include <ossimHgtRef.h>

Public Member Functions
	ossimHgtRef (HeightRefType_t cRefType)
	constructor. More...
	ossimHgtRef (HeightRefType_t cRefType, const ossim_float64 &atHgt)
virtual	~ossimHgtRef ()
	virtual destructor. More...
HeightRefType_t	getHeightRefType () const
	Method to get height reference type (ellipsoid or DEM). More...
virtual ossim_float64	getRefHeight (const ossimGpt &pg) const
	Method to get height reference. More...
virtual bool	getSurfaceCovMatrix (const ossimGpt &pg, NEWMAT::Matrix &cov) const
	Method to get surface information string. More...
virtual bool	getSurfaceCovMatrix (const ossim_float64 refCE, const ossim_float64 refLE, NEWMAT::Matrix &cov) const
	Method to get surface covariance matrix. More...
bool	getSurfaceNormalCovMatrix (const ossimGpt &pg, const NEWMAT::Matrix &surfCov, NEWMAT::Matrix &normCov) const
	Method to get surface normal covariance matrix. More...
virtual ossimColumnVector3d	getLocalTerrainNormal (const ossimGpt &pg) const
	Method to get local terrain normal unit vector (slope). More...

Private Attributes
HeightRefType_t	theCurrentHeightRefType
ossim_float64	theCurrentRefHeight

Detailed Description

Definition at line 24 of file ossimHgtRef.h.

Constructor & Destructor Documentation

ossimHgtRef() [1/2]

ossimHgtRef::ossimHgtRef

(

HeightRefType_t

cRefType

)

constructor.

Definition at line 37 of file ossimHgtRef.cpp.

:
theCurrentHeightRefType(cRefType)
{
   if (traceDebug())
   {
      ossimNotify(ossimNotifyLevel_DEBUG)
         << "ossimHgtRef::ossimHgtRef DEBUG:" << std::endl;
#ifdef OSSIM_ID_ENABLED
      ossimNotify(ossimNotifyLevel_DEBUG)
         << "OSSIM_ID:  " << OSSIM_ID << std::endl;
#endif 
   }
   
}

ossimHgtRef() [2/2]

ossimHgtRef::ossimHgtRef	(	HeightRefType_t	cRefType,
		const ossim_float64 &	atHgt
	)

Definition at line 60 of file ossimHgtRef.cpp.

:
theCurrentHeightRefType(cRefType),
theCurrentRefHeight(atHgt)
{
   if (traceDebug())
   {
      ossimNotify(ossimNotifyLevel_DEBUG)
         << "ossimHgtRef::ossimHgtRef DEBUG:" << std::endl;
#ifdef OSSIM_ID_ENABLED
      ossimNotify(ossimNotifyLevel_DEBUG)
         << "OSSIM_ID:  " << OSSIM_ID << std::endl;
#endif 
   }
   
}

~ossimHgtRef()

ossimHgtRef::~ossimHgtRef ( )

virtual

virtual destructor.

Definition at line 79 of file ossimHgtRef.cpp.

{
}

Member Function Documentation

getHeightRefType()

HeightRefType_t ossimHgtRef::getHeightRefType ( ) const

inline

Method to get height reference type (ellipsoid or DEM).

Definition at line 42 of file ossimHgtRef.h.

{return theCurrentHeightRefType;}

getLocalTerrainNormal()

ossimColumnVector3d ossimHgtRef::getLocalTerrainNormal ( const ossimGpt &  pg ) const

virtual

Method to get local terrain normal unit vector (slope).

Parameters

pg	Reference point.

Returns

ossimColumnVector3D.

Definition at line 395 of file ossimHgtRef.cpp.

References AT_DEM, AT_HGT, ossimElevManager::getHeightAboveEllipsoid(), ossimGpt::height(), ossimElevManager::instance(), ossimGpt::latd(), ossimGpt::lond(), ossimGpt::metersPerDegree(), theCurrentHeightRefType, ossimDpt::x, ossimDpt::y, and ossimColumnVector3d::zAligned().

{
   ossimColumnVector3d tNorm;
   const ossim_float64 delta = 100.0;
   
   switch (theCurrentHeightRefType)
   {
      case AT_HGT:
         // Use ellipsoid tangent plane mormal
         tNorm = tNorm.zAligned();
         break;
         
      case AT_DEM:
         {
            // Use local 3X3 grid around point to get mean slope
            NEWMAT::Matrix h(3,3);
            ossimDpt mpd;
            mpd = pg.metersPerDegree();
            ossim_float64 dLon = delta/mpd.x;
            ossim_float64 dLat = delta/mpd.y;


            for (ossim_int32 lon=-1; lon<=1; ++lon)
            {
               ossim_float64 clon = pg.lond()+lon*dLon;
               for (ossim_int32 lat=-1; lat<=1; ++lat)
               {
                  ossim_float64 clat = pg.latd()+lat*dLat;
                  ossimGpt p(clat, clon, pg.height());
                  h(2-lat,lon+2) =
                     ossimElevManager::instance()->getHeightAboveEllipsoid(p);
               }
            }
            
            if (traceDebug())
            {
               ossimNotify(ossimNotifyLevel_DEBUG)
                  <<"DEBUG: getLocalTerrainNormal...  3X3 grid"<<endl;
               for (ossim_int32 lat=-1; lat<=1; ++lat)
               {
                  for (ossim_int32 lon=-1; lon<=1; ++lon)
                    ossimNotify(ossimNotifyLevel_DEBUG)<<"  "<<h(lat+2,lon+2);
                  ossimNotify(ossimNotifyLevel_DEBUG)<<endl;
               }
            }

            ossim_float64 dz_dlon =
                  ((h(1,3)+2*h(2,3)+h(3,3))-(h(1,1)+2*h(2,1)+h(3,1)))/(8*delta);
            ossim_float64 dz_dlat =
                  ((h(1,1)+2*h(1,2)+h(1,3))-(h(3,1)+2*h(3,2)+h(3,3)))/(8*delta);
            tNorm[0] = -dz_dlon;
            tNorm[1] = -dz_dlat;
            tNorm[2] = 1.0 - sqrt(dz_dlon*dz_dlon+dz_dlat*dz_dlat);
         }
         
         // If error condition, return z-aligned vector to allow continuation
         if (ossim::isnan(tNorm[0]) ||
             ossim::isnan(tNorm[1]) ||
             ossim::isnan(tNorm[2]))
         {
            tNorm = tNorm.zAligned();
            if(traceDebug())
            {
               ossimNotify(ossimNotifyLevel_WARN)
                  << "WARNING: ossimHgtRef::getLocalTerrainNormal(): "
                  << "\n   error... terrain normal set to vertical..."
                  << std::endl;
               
            }
         }
         break;
         
      default:
         tNorm = tNorm.zAligned();
         break;
   }

   return tNorm;
}

getRefHeight()

ossim_float64 ossimHgtRef::getRefHeight ( const ossimGpt &  pg ) const

virtual

Method to get height reference.

Parameters

pg	Reference point.

Returns

Height at reference point.

Definition at line 90 of file ossimHgtRef.cpp.

References AT_DEM, AT_HGT, ossimElevManager::getHeightAboveEllipsoid(), ossimElevManager::instance(), theCurrentHeightRefType, and theCurrentRefHeight.

Referenced by ossimSarModel::projOPtoSurface().

{
   ossim_float64 refHgt;
   
   switch (theCurrentHeightRefType)
   {
      case AT_HGT:
         refHgt = theCurrentRefHeight;
         break;
      case AT_DEM:
         refHgt = ossimElevManager::instance()->getHeightAboveEllipsoid(pg);
         break;
      default:
         refHgt = 0.0;
         break;
   }
         
   return refHgt;
}

getSurfaceCovMatrix() [1/2]

bool ossimHgtRef::getSurfaceCovMatrix ( const ossimGpt &  pg, NEWMAT::Matrix &  cov  ) const

virtual

Method to get surface information string.

Parameters

pg	Reference point.
info	ossimElevationAccuracyInfo string.

Returns

true on success, false on error. Method to get surface covariance matrix.

Parameters

pg	Reference point.
cov	3X3 ENU covariance matrix.

Returns

true on success, false on error.

Definition at line 176 of file ossimHgtRef.cpp.

References AT_DEM, AT_HGT, ossimElevManager::getAccuracyInfo(), ossimElevationAccuracyInfo::hasValidAbsoluteError(), ossimElevManager::instance(), ossimElevationAccuracyInfo::m_absoluteCE, ossimElevationAccuracyInfo::m_absoluteLE, theCurrentHeightRefType, and ossimDpt::x.

{
   
   ossim_float64 refCE;
   ossim_float64 refLE;
   ossimString info;
   ossimDpt gsd;

   switch (theCurrentHeightRefType)
   {
      case AT_HGT:
         // Set the reference CE/LE
         //   Note: currently set to reflect no contribution
         refCE = 0.0;
         refLE = .01;
         
         break;
         
      case AT_DEM:
      {

         // Set the reference CE/LE
         //   Note: currently set to SRTM spec in METERS
         //    refCE = 20.0;
         //    refLE = 16.0;
         //        (ref: www2.jpl.nas.gov/srtm/statistics.html)
         //  "refCE = ossimElevManager::instance()->getAccuracyCE90(pg)" is
         //    the desirable operation here (if it is implemented)
         // ================================================
         //  This is one step closer to automatic
         //  access to elevation surface accuracy
         //   TODO...
         //     [1] load from OSSIM_PREFERENCES?
         //     [2] does DTED header/metadata have info?
         // ================================================
         ossimElevationAccuracyInfo info;
         ossimElevManager::instance()->getAccuracyInfo(info, pg);

         if(info.hasValidAbsoluteError())
         {
            refCE = info.m_absoluteCE;
            refLE = info.m_absoluteLE;
         }
         else
         {
            refCE = 20.0;
            refLE = 16.0;
         }
#if 0
         if (getSurfaceInfo(pg, info, gsd))
         {
            if (info.contains("Srtm"))
            {
               if (gsd.x < 50.0)
               {
                  // SRTM 1 arc
                  refCE = 20.0;
                  refLE = 10.0;
               }
               else
               {
                  // SRTM 3 arc
                  refCE = 20.0;
                  refLE = 16.0;
               }
            }
            else if (info.contains("Dted"))
            {
               if (gsd.x < 50.0)
               {
                  // DTED level 2
                  refCE = 40.0;
                  refLE = 20.0;
               }
               else
               {
                  // DTED level 1
                  refCE = 50.0;
                  refLE = 30.0;
               }
            }
            else
            {
               // Other
               refCE = 20.0;
               refLE = 16.0;
            }
         }
         if (traceDebug())
         {
            ossimNotify(ossimNotifyLevel_DEBUG)
               //<< "DEBUG: info: " << info
               << " ref: " << refCE << "/" << refLE << endl;
         }
#endif

         break;
      }
      default:
         return false;
         break;
   }
   
   // Form the covariance matrix
   //  A circular error ellipse with no correlation must be assumed.
   cov = 0.0;
   cov(1,1) = refCE/2.146;
   cov(2,2) = refCE/2.146;
   cov(3,3) = refLE/1.6449;
   cov(1,1) *= cov(1,1);
   cov(2,2) *= cov(2,2);
   cov(3,3) *= cov(3,3);
   
   return true;
}

getSurfaceCovMatrix() [2/2]

bool ossimHgtRef::getSurfaceCovMatrix ( const ossim_float64  refCE, const ossim_float64  refLE, NEWMAT::Matrix &  cov  ) const

virtual

Method to get surface covariance matrix.

METHOD: ossimHgtRef::getSurfaceCovMatrix()

Parameters

refCE	Reference surface 90% CE [m]
refLE	Reference surface 90% LE [m]
cov	3X3 ENU covariance matrix.

Returns

true on success, false on error.

Definition at line 299 of file ossimHgtRef.cpp.

References AT_DEM, AT_HGT, and theCurrentHeightRefType.

{
   ossim_float64 useCE;
   ossim_float64 useLE;
   
   if (refCE<0.0 || refLE<0.0)
   {
      return false;
   }
   
   switch (theCurrentHeightRefType)
   {
      case AT_HGT:
         // Set the reference CE/LE
         //   Note: currently set to reflect no contribution
         useCE = 0.0;
         useLE = .01;
         
         break;
         
      case AT_DEM:
         // Set the reference CE/LE
         useCE = refCE;
         useLE = refLE;
         
         break;
         
      default:
         return false;
         break;
   }
   
   // Form the covariance matrix
   //  A circular error ellipse with no correlation must be assumed.
   cov = 0.0;
   cov(1,1) = useCE/2.146;
   cov(2,2) = useCE/2.146;
   cov(3,3) = useLE/1.6449;
   cov(1,1) *= cov(1,1);
   cov(2,2) *= cov(2,2);
   cov(3,3) *= cov(3,3);
   
   return true;
}

getSurfaceNormalCovMatrix()

bool ossimHgtRef::getSurfaceNormalCovMatrix	(	const ossimGpt &	pg,
		const NEWMAT::Matrix &	surfCov,
		NEWMAT::Matrix &	normCov
	)		const

Method to get surface normal covariance matrix.

Parameters

pg	Reference point.
surfCov	3X3 ENU surface covariance matrix.
normCov	3X3 ECF normal covariance matrix.

Returns

true on success, false on error.

Definition at line 355 of file ossimHgtRef.cpp.

References ossimLsrSpace::lsrToEcefRotMatrix().

{
   // Set the local frame
   ossimLsrSpace enu(pg);

   // Propagate the reference covariance matrix to ECF
   NEWMAT::Matrix covEcf;
   covEcf = enu.lsrToEcefRotMatrix() * surfCov * enu.lsrToEcefRotMatrix().t();

   // Get surface normal vector in ENU
   ossimColumnVector3d sn = getLocalTerrainNormal(pg);
   NEWMAT::Matrix tnU(3,1);
   tnU << sn[0] << sn[1] << sn[2];

   // Rotate surface normal to ECF
   NEWMAT::Matrix tnUecf(3,1);
   tnUecf = enu.lsrToEcefRotMatrix() * tnU;

   // Propagate to terrain normal
   NEWMAT::Matrix ptn;
   NEWMAT::SymmetricMatrix ptns;
   ptn = tnUecf.t() * covEcf * tnUecf;
   ptns << ptn;

   // And back to ECF
   normCov = tnUecf * ptns * tnUecf.t();


   return true;
}

Member Data Documentation

theCurrentHeightRefType

HeightRefType_t ossimHgtRef::theCurrentHeightRefType

private

Definition at line 116 of file ossimHgtRef.h.

Referenced by getLocalTerrainNormal(), getRefHeight(), and getSurfaceCovMatrix().

theCurrentRefHeight

ossim_float64 ossimHgtRef::theCurrentRefHeight

private

Definition at line 117 of file ossimHgtRef.h.

Referenced by getRefHeight().

---

The documentation for this class was generated from the following files:

• ossimHgtRef.h
• ossimHgtRef.cpp