org.ka2ddo.yaac.srtm

Class SRTMTileManager

java.lang.Object

org.ka2ddo.yaac.srtm.SRTMTileManager

public class SRTMTileManager
extends java.lang.Object

This class manages an in-memory cache of SRTMTile objects, as well as providing I/O code to fetch new tiles from the USGS website.

Author:

Andrew Pavlin, KA2DDO

Method Summary

Modifier and Type	Method and Description
void	flushFileCache() Clear cached pointers to tile files.
short	getElevation(double latitude, double longitude) Get the SRTM elevation at the specified lat/lon coordinates.
int	getEstimatedCacheSize() Get an estimate of the amount of memory used by the SRTM tile cache.
static SRTMTileManager	getInstance() Get the reference to the singleton SRTMTileManager object.
SRTMTile	getTile(double latitude, double longitude) Get a SRTMTile object for the 1-degree by 1-degree region of the planet requested.
SRTMTile	getTile(int latitude, int longitude) Get a SRTMTile object for the 1-degree by 1-degree region of the planet requested.
static void	loadPrecompiledTiles(double radius, double lat, double lon, boolean hiRes) Download NASADEM tiles from the US Geological Survey's LP DAAC website to cover a specified region of the planet.

Methods inherited from class java.lang.Object

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

Method Detail

getInstance

public static SRTMTileManager getInstance()

Get the reference to the singleton SRTMTileManager object.

Returns:

SRTMTileManager instance

getTile

public SRTMTile getTile(int latitude,
                        int longitude)

Get a SRTMTile object for the 1-degree by 1-degree region of the planet requested.

Parameters:

latitude - int latitude in millionths of degrees North

longitude - int longitude in millionths of degrees East

Returns:

SRTMTile object containing elevation data for the specified latitude/longitude

getTile

public SRTMTile getTile(double latitude,
                        double longitude)

Get a SRTMTile object for the 1-degree by 1-degree region of the planet requested.

Parameters:

latitude - double latitude in fractional degrees North

longitude - double longitude in fractional degrees East

Returns:

SRTMTile object containing elevation data for the specified latitude/longitude

getElevation

public short getElevation(double latitude,
                          double longitude)

Get the SRTM elevation at the specified lat/lon coordinates.

Parameters:

latitude - double latitude in fractional degrees North

longitude - double longitude in fractional degrees East

Returns:

elevation at the tile pixel for the specified coordinates, or NO_CELL if there is no tile for the specified coordinates

flushFileCache

public void flushFileCache()

Clear cached pointers to tile files. This is called when the configuration dialog changes the tile root directory path.

getEstimatedCacheSize

public int getEstimatedCacheSize()

Get an estimate of the amount of memory used by the SRTM tile cache.

Returns:

estimated byte count used by tiles in memory

loadPrecompiledTiles

public static void loadPrecompiledTiles(double radius,
                                        double lat,
                                        double lon,
                                        boolean hiRes)

Download NASADEM tiles from the US Geological Survey's LP DAAC website to cover a specified region of the planet. Note these are exactly the same format as SRTM1 tiles from the former unsecured USGS website.

Parameters:

radius - radius to cover in kilometers

lat - center latitude of region to download in fractional degrees North

lon - center longitude of region to download in fractional degrees East

hiRes - boolean true if 1-arc-second tiles should be downloaded where available (currently ignored)