Package org.orekit.rugged.raster

Class SimpleTile

java.lang.Object

org.orekit.rugged.raster.SimpleTile

All Implemented Interfaces:

Tile, UpdatableTile

Direct Known Subclasses:

MinMaxTreeTile

public class SimpleTile
extends Object
implements Tile

Simple implementation of a Tile.

Author:

Luc Maisonobe, Guylaine Prat

See Also:

SimpleTileFactory

Nested Class Summary

Nested classes/interfaces inherited from interface org.orekit.rugged.raster.Tile

Tile.Location

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	SimpleTile()	Simple constructor.

Method Summary

Modifier and Type	Method	Description
NormalizedGeodeticPoint	cellIntersection(NormalizedGeodeticPoint p, Vector3D los, int latitudeIndex, int longitudeIndex)	Find the intersection of a line-of-sight and a Digital Elevation Model cell.
protected double	getDoubleLatitudeIndex(double latitude)	Get the latitude index of a point.
protected double	getDoubleLongitudeIndex(double longitude)	Get the longitude index of a point.
double	getElevationAtIndices(int latitudeIndex, int longitudeIndex)	Get the elevation of an exact grid point.
int	getFloorLatitudeIndex(double latitude)	Get the floor latitude index of a point.
int	getFloorLongitudeIndex(double longitude)	Get the floor longitude index of a point.
double	getLatitudeAtIndex(int latitudeIndex)	Get the latitude at some index.
int	getLatitudeRows()	Get number of latitude rows.
double	getLatitudeStep()	Get step in latitude (size of one raster element).
Tile.Location	getLocation(double latitude, double longitude)	Check if a tile covers a ground point.
double	getLongitudeAtIndex(int longitudeIndex)	Get the longitude at some index.
int	getLongitudeColumns()	Get number of longitude columns.
double	getLongitudeStep()	Get step in longitude (size of one raster element).
double	getMaxElevation()	Get the maximum elevation in the tile.
int	getMaxElevationLatitudeIndex()	Get the latitude index of max elevation.
int	getMaxElevationLongitudeIndex()	Get the longitude index of max elevation.
double	getMaximumLatitude()	Get maximum latitude.
double	getMaximumLongitude()	Get maximum longitude.
double	getMinElevation()	Get the minimum elevation in the tile.
int	getMinElevationLatitudeIndex()	Get the latitude index of min elevation.
int	getMinElevationLongitudeIndex()	Get the longitude index of min elevation.
double	getMinimumLatitude()	Get minimum latitude of grid interpolation points.
double	getMinimumLongitude()	Get minimum longitude.
double	interpolateElevation(double latitude, double longitude)	Interpolate elevation.
protected void	processUpdatedElevation(double[] elevationsArray)	Process elevation array at completion.
void	setElevation(int latitudeIndex, int longitudeIndex, double elevation)	Set the elevation for one raster element.
void	setGeometry(double newMinLatitude, double newMinLongitude, double newLatitudeStep, double newLongitudeStep, int newLatitudeRows, int newLongitudeColumns)	Set the tile global geometry.
void	tileUpdateCompleted()	Hook called at the end of tile update completion.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

SimpleTile

protected SimpleTile()

Simple constructor.

Creates an empty tile.

Method Detail

setGeometry

public void setGeometry(double newMinLatitude,
                        double newMinLongitude,
                        double newLatitudeStep,
                        double newLongitudeStep,
                        int newLatitudeRows,
                        int newLongitudeColumns)

Set the tile global geometry.

Specified by:

setGeometry in interface UpdatableTile

Parameters:

newMinLatitude - minimum latitude (rad)

newMinLongitude - minimum longitude (rad)

newLatitudeStep - step in latitude (size of one raster element) (rad)

newLongitudeStep - step in longitude (size of one raster element) (rad)

newLatitudeRows - number of latitude rows

newLongitudeColumns - number of longitude columns

tileUpdateCompleted

public void tileUpdateCompleted()

Hook called at the end of tile update completion.

Specified by:

tileUpdateCompleted in interface Tile

processUpdatedElevation

protected void processUpdatedElevation(double[] elevationsArray)

Process elevation array at completion.

This method is called at tile update completion, it is expected to be overridden by subclasses. The default implementation does nothing.

Parameters:

elevationsArray - elevations array

getMinimumLatitude

public double getMinimumLatitude()

Get minimum latitude of grid interpolation points.

Specified by:

getMinimumLatitude in interface Tile

Returns:

minimum latitude of grid interpolation points (rad) (latitude of the center of the cells of South row)

getLatitudeAtIndex

public double getLatitudeAtIndex(int latitudeIndex)

Get the latitude at some index.

Specified by:

getLatitudeAtIndex in interface Tile

Parameters:

latitudeIndex - latitude index

Returns:

latitude at the specified index (rad) (latitude of the center of the cells of specified row)

getMaximumLatitude

public double getMaximumLatitude()

Get maximum latitude.

Beware that as a point at maximum latitude is the northernmost one of the grid, it doesn't have a northwards neighbor and therefore calling getLocation on such a latitude will return either Tile.Location.NORTH_WEST, Tile.Location.NORTH or Tile.Location.NORTH_EAST, but can never return Tile.Location.HAS_INTERPOLATION_NEIGHBORS!

Specified by:

getMaximumLatitude in interface Tile

Returns:

maximum latitude (rad) (latitude of the center of the cells of North row)

getMinimumLongitude

public double getMinimumLongitude()

Get minimum longitude.

Specified by:

getMinimumLongitude in interface Tile

Returns:

minimum longitude (rad) (longitude of the center of the cells of West column)

getLongitudeAtIndex

public double getLongitudeAtIndex(int longitudeIndex)

Get the longitude at some index.

Specified by:

getLongitudeAtIndex in interface Tile

Parameters:

longitudeIndex - longitude index

Returns:

longitude at the specified index (rad) (longitude of the center of the cells of specified column)

getMaximumLongitude

public double getMaximumLongitude()

Get maximum longitude.

Beware that as a point at maximum longitude is the easternmost one of the grid, it doesn't have an eastwards neighbor and therefore calling getLocation on such a longitude will return either Tile.Location.SOUTH_EAST, Tile.Location.EAST or Tile.Location.NORTH_EAST, but can never return Tile.Location.HAS_INTERPOLATION_NEIGHBORS!

Specified by:

getMaximumLongitude in interface Tile

Returns:

maximum longitude (rad) (longitude of the center of the cells of East column)

getLatitudeStep

public double getLatitudeStep()

Get step in latitude (size of one raster element).

Specified by:

getLatitudeStep in interface Tile

Returns:

step in latitude (rad)

getLongitudeStep

public double getLongitudeStep()

Get step in longitude (size of one raster element).

Specified by:

getLongitudeStep in interface Tile

Returns:

step in longitude (rad)

getLatitudeRows

public int getLatitudeRows()

Get number of latitude rows.

Specified by:

getLatitudeRows in interface Tile

Returns:

number of latitude rows

getLongitudeColumns

public int getLongitudeColumns()

Get number of longitude columns.

Specified by:

getLongitudeColumns in interface Tile

Returns:

number of longitude columns

getMinElevation

public double getMinElevation()

Get the minimum elevation in the tile.

Specified by:

getMinElevation in interface Tile

Returns:

minimum elevation in the tile (m)

getMinElevationLatitudeIndex

public int getMinElevationLatitudeIndex()

Get the latitude index of min elevation.

Specified by:

getMinElevationLatitudeIndex in interface Tile

Returns:

latitude index of min elevation

getMinElevationLongitudeIndex

public int getMinElevationLongitudeIndex()

Get the longitude index of min elevation.

Specified by:

getMinElevationLongitudeIndex in interface Tile

Returns:

longitude index of min elevation

getMaxElevation

public double getMaxElevation()

Get the maximum elevation in the tile.

Specified by:

getMaxElevation in interface Tile

Returns:

maximum elevation in the tile (m)

getMaxElevationLatitudeIndex

public int getMaxElevationLatitudeIndex()

Get the latitude index of max elevation.

Specified by:

getMaxElevationLatitudeIndex in interface Tile

Returns:

latitude index of max elevation

getMaxElevationLongitudeIndex

public int getMaxElevationLongitudeIndex()

Get the longitude index of max elevation.

Specified by:

getMaxElevationLongitudeIndex in interface Tile

Returns:

longitude index of max elevation

setElevation

public void setElevation(int latitudeIndex,
                         int longitudeIndex,
                         double elevation)

Set the elevation for one raster element.

BEWARE! The order of the indices follows geodetic conventions, i.e. the latitude is given first and longitude afterwards, so the first index specifies a row index with zero at South and max value at North, and the second index specifies a column index with zero at West and max value at East. This is not the same as some raster conventions (as our row index increases from South to North) and this is also not the same as Cartesian coordinates as our ordinate index appears before our abscissa index).

Specified by:

setElevation in interface UpdatableTile

Parameters:

latitudeIndex - index of latitude (row index)

longitudeIndex - index of longitude (column index)

elevation - elevation (m)

getElevationAtIndices

public double getElevationAtIndices(int latitudeIndex,
                                    int longitudeIndex)

Get the elevation of an exact grid point.

Specified by:

getElevationAtIndices in interface Tile

Parameters:

latitudeIndex - grid point index along latitude

longitudeIndex - grid point index along longitude

Returns:

elevation at grid point (m)

interpolateElevation

public double interpolateElevation(double latitude,
                                   double longitude)

Interpolate elevation.

In order to cope with numerical accuracy issues when computing points at tile boundary, a slight tolerance (typically 1/8 cell) around the tile is allowed. Elevation can therefore be interpolated (really extrapolated in this case) even for points slightly overshooting tile boundaries, using the closest tile cell. Attempting to interpolate too far from the tile will trigger an exception.

This classes uses an arbitrary 1/8 cell tolerance for interpolating slightly out of tile points.

Specified by:

interpolateElevation in interface Tile

Parameters:

latitude - ground point latitude

longitude - ground point longitude

Returns:

interpolated elevation (m)

cellIntersection

public NormalizedGeodeticPoint cellIntersection(NormalizedGeodeticPoint p,
                                                Vector3D los,
                                                int latitudeIndex,
                                                int longitudeIndex)

Find the intersection of a line-of-sight and a Digital Elevation Model cell.

Beware that for continuity reasons, the point argument in cellIntersection is normalized with respect to other points used by the caller. This implies that the longitude may be outside of the [-π ; +π] interval (or the [0 ; 2π] interval, depending on the DEM). In particular, when a Line Of Sight crosses the antimeridian at ±π longitude, the library may call the cellIntersection method with a point having a longitude of -π-ε to ensure this continuity. As tiles are stored with longitude clipped to a some DEM specific interval (either [-π ; +π] or [0 ; 2π]), implementations MUST take care to clip the input point back to the tile interval using MathUtils.normalizeAngle(p.getLongitude(), someLongitudeWithinTheTile). The output point normalization should also be made consistent with the current tile.

Specified by:

cellIntersection in interface Tile

Parameters:

p - point on the line (beware its longitude is not normalized with respect to tile)

los - line-of-sight, in the topocentric frame (East, North, Zenith) of the point, scaled to match radians in the horizontal plane and meters along the vertical axis

latitudeIndex - latitude index of the Digital Elevation Model cell

longitudeIndex - longitude index of the Digital Elevation Model cell

Returns:

point corresponding to line-of-sight crossing the Digital Elevation Model surface if it lies within the cell, null otherwise

getFloorLatitudeIndex

public int getFloorLatitudeIndex(double latitude)

Get the floor latitude index of a point.

The specified latitude is always between index and index+1.

Specified by:

getFloorLatitudeIndex in interface Tile

Parameters:

latitude - geodetic latitude

Returns:

floor latitude index (it may lie outside of the tile!)

getFloorLongitudeIndex

public int getFloorLongitudeIndex(double longitude)

Get the floor longitude index of a point.

The specified longitude is always between index and index+1.

Specified by:

getFloorLongitudeIndex in interface Tile

Parameters:

longitude - geodetic longitude

Returns:

floor longitude index (it may lie outside of the tile!)

getDoubleLatitudeIndex

protected double getDoubleLatitudeIndex(double latitude)

Get the latitude index of a point.

Parameters:

latitude - geodetic latitude (rad)

Returns:

latitude index (it may lie outside of the tile!)

getDoubleLongitudeIndex

protected double getDoubleLongitudeIndex(double longitude)

Get the longitude index of a point.

Parameters:

longitude - geodetic longitude (rad)

Returns:

longitude index (it may lie outside of the tile!)

getLocation

public Tile.Location getLocation(double latitude,
                                 double longitude)

Check if a tile covers a ground point.

Specified by:

getLocation in interface Tile

Parameters:

latitude - ground point latitude

longitude - ground point longitude

Returns:

location of the ground point with respect to tile