## com.bbn.openmap.dataAccess.dted
Class DTEDFrameCache

    java.lang.Object
      com.bbn.openmap.layer.util.cacheHandler.CacheHandler
          com.bbn.openmap.dataAccess.dted.DTEDFrameCache

All Implemented Interfaces:
  PropertyConsumer

public class DTEDFrameCache
extends CacheHandler
implements PropertyConsumer

The DTEDFrameCache is an object that retrieves DTED paths, frames or elevation values, given a latitude, logitude and dted level. It maintains a collection of the frames it has already used for quicker access later. The size of the cache is determined by startup settings.

The DTEDFrameCache can be placed in the MapHandler, where other objects can share it in order to all use the same DTED data. It can be configured with properties:

             frameCache.cacheSize=40
             frameCache.directoryHandlers=dteddir1 dteddir2
             frameCache.dteddir1.translator=com.bbn.openmap.dataAccess.dted.StandardDTEDNameTranslator
             frameCache.dteddir1.path=/data/dted
             frameCache.dteddir2.translator=com.bbn.openmap.dataAccess.dted.StandardDTEDNameTranslator
             frameCache.dteddir2.path=/data/dted

A DTEDDirectoryHandler needs to be specified for each DTED directory you want to use. If a translator isn't specified in the properties for a directory handler, the StandardDTEDNameTranslator will be used. If you have DTED data that doesn't conform to the naming conventions specified in the Military Standard, you can use a different DTEDNameTranslator instead for your particular directory handler.

Field Summary
`int` `DEFAULT_CACHE_SIZE`
`protected java.util.Vector` `directories`
`static java.lang.String` `DTEDDirectoryHandlerProperty`
`static java.lang.String` `DTEDFrameCacheSizeProperty`
`protected int` `highestResLevel`
`static int` `NO_DATA` The elevation value returned if there is no data at a lat/lon (-32767).
`protected java.lang.String` `propertyPrefix`

Fields inherited from class com.bbn.openmap.layer.util.cacheHandler.CacheHandler
`DEFAULT_MAX_CACHE_SIZE, logicalClock, objs`

Fields inherited from interface com.bbn.openmap.PropertyConsumer
`EditorProperty, initPropertiesProperty, LabelEditorProperty, ScopedEditorProperty`

Constructor Summary
`DTEDFrameCache()`
`DTEDFrameCache(int max_size)` Create the cache with paths to search for frames, and the maximum number of frames to keep on hand.

Method Summary
`void` `addDTEDDirectoryHandler(DTEDDirectoryHandler handler)` Add a DTED DirectoryHandler to be used for the DTEDFrameCache.
`java.lang.String` `findFileName(double lat, double lon, int level)` A utility to find the path to a dted file, given a lat, lon and a dted level.
`DTEDFrame` `get(double lat, double lon, int level)` Return The DTED Frame, Given A Lat, Lon And DTED Level.
`java.util.Vector` `getDTEDDirectoryHandlers()` Get the Vector of DTEDDirectoryHandlers used by the DTEDFrameCache.
`int` `getElevation(float lat, float lon)` Return the elevation of a lat/lon point, in meters.
`int` `getElevation(float lat, float lon, int level)` Return the elevation of a lat/lon point, in meters.
`short[][]` `getElevations(EqualArc proj, int dtedLevel)` Return the two-dimensional matrix of elevation posts (heights) representing coverage of a given geographical rectangle.
`short[][]` `getElevations(float ullat, float ullon, float lrlat, float lrlon, int dtedLevel)` Return the two-dimensional matrix of elevation posts (heights) representing coverage of a given geographical rectangle.
`protected short[][]` `getElevations(float ullat, float ullon, float lrlat, float lrlon, int dtedLevel, DTEDFrame refFrame)` Return the two-dimensional matrix of elevation posts (heights) representing coverage of a given geographical rectangle.
`int` `getHighestResLevel()`
`java.util.Properties` `getProperties(java.util.Properties props)` PropertyConsumer method.
`java.util.Properties` `getPropertyInfo(java.util.Properties props)` PropertyConsumer method.
`java.lang.String` `getPropertyPrefix()` PropertyConsumer method.
`CacheObject` `load(java.lang.String dtedFramePath)` Load a dted frame into the cache, based on the path of the frame as a key.
`static void` `main(java.lang.String[] args)`
`void` `removeDTEDDirectoryHandler(DTEDDirectoryHandler handler)` Remove a DTED DirectoryHandler from the list used for the DTEDFrameCache.
`void` `resizeCache(int max_size)` This version of resizeCache is for screen size changes, where the number of frames kept on hand in the cache must change, but the images themselves don't have to because the pixel/posting spacing hasn't changed in the projection.
`void` `setDTEDDirectoryHandlers(java.util.Vector handlers)` Set the Vector of DTEDDirectoryHandlers used by the DTEDFrameCache.
`void` `setHighestResLevel(int highestResLevel)`
`void` `setProperties(java.util.Properties props)` PropertyConsumer method.
`void` `setProperties(java.lang.String prefix, java.util.Properties props)` PropertyConsumer method.
`void` `setPropertyPrefix(java.lang.String prefix)` PropertyConsumer method.

Methods inherited from class com.bbn.openmap.layer.util.cacheHandler.CacheHandler
`clear, get, getCacheSize, listIterator, replaceLeastUsed, resetCache, resetCache, searchCache`

Methods inherited from class java.lang.Object
`clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

Field Detail

### NO_DATA

    public static final int NO_DATA

  The elevation value returned if there is no data at a lat/lon (-32767).

  See Also:
    Constant Field Values

### DTEDDirectoryHandlerProperty

    public static final java.lang.String DTEDDirectoryHandlerProperty

See Also:
  Constant Field Values

### DTEDFrameCacheSizeProperty

    public static final java.lang.String DTEDFrameCacheSizeProperty

See Also:
  Constant Field Values

### DEFAULT_CACHE_SIZE

    public int DEFAULT_CACHE_SIZE

### propertyPrefix

    protected java.lang.String propertyPrefix

### directories

    protected java.util.Vector directories

### highestResLevel

    protected int highestResLevel

Constructor Detail

### DTEDFrameCache

    public DTEDFrameCache()

### DTEDFrameCache

    public DTEDFrameCache(int max_size)

  Create the cache with paths to search for frames, and the maximum number of frames to keep on hand. Assumes the paths given are for level 0 and 1 data.

Parameters:
  `max_size` - max number of frames to keep in the cache..

Method Detail

### addDTEDDirectoryHandler

    public void addDTEDDirectoryHandler(DTEDDirectoryHandler handler)

  Add a DTED DirectoryHandler to be used for the DTEDFrameCache.

### removeDTEDDirectoryHandler

    public void removeDTEDDirectoryHandler(DTEDDirectoryHandler handler)

  Remove a DTED DirectoryHandler from the list used for the DTEDFrameCache.

### getDTEDDirectoryHandlers

    public java.util.Vector getDTEDDirectoryHandlers()

  Get the Vector of DTEDDirectoryHandlers used by the DTEDFrameCache.

### setDTEDDirectoryHandlers

    public void setDTEDDirectoryHandlers(java.util.Vector handlers)

  Set the Vector of DTEDDirectoryHandlers used by the DTEDFrameCache. You might want to use this to set the order of directories that are searched for a DTED frame.

### findFileName

    public java.lang.String findFileName(double lat,
                                         double lon,
                                         int level)

  A utility to find the path to a dted file, given a lat, lon and a dted level. Assumes that paths have been given to the cache. Lat/lons in decimal degrees.

  Parameters:
    `lat` - latitude of point
    `lon` - longitude of point
    `level` - the dted level wanted (0, 1)
  Returns:
    complete path to file with lat/lon.

### get

    public DTEDFrame get(double lat,
                         double lon,
                         int level)

  Return The DTED Frame, Given A Lat, Lon And DTED Level.

  Parameters:
    `lat` - latitude of point
    `lon` - longitude of point
    `level` - the dted level wanted (0, 1, 2)
  Returns:
    DTED frame.

### load

    public CacheObject load(java.lang.String dtedFramePath)

  Load a dted frame into the cache, based on the path of the frame as a key.

  Specified by:
    `load` in class `CacheHandler`
  Parameters:
    `dtedFramePath` - complete path to the frame.
  Returns:
    DTED frame, hidden as a CacheObject.

### resizeCache

    public void resizeCache(int max_size)

  This version of resizeCache is for screen size changes, where the number of frames kept on hand in the cache must change, but the images themselves don't have to because the pixel/posting spacing hasn't changed in the projection. The frames already in the cache are re-added to the new cache, if the cache size is increasing. If the cache size is shrinking, then as many as will fit are added to the new cache.

  Parameters:
    `max_size` - the new size of the cache.

### getHighestResLevel

    public int getHighestResLevel()

### setHighestResLevel

    public void setHighestResLevel(int highestResLevel)

### getElevation

    public int getElevation(float lat,
                            float lon)

  Return the elevation of a lat/lon point, in meters. Will look for frames starting at the highest resolution specified in this DTEDFrameCache, and work up to level 0, searching for a frame to provide an answer. Will return NO_DATA if a frame is not found, or if there is no data in the frame file that is found. The default highest resolution DTED level is 2.

  Parameters:
    `lat` - in decimal degrees.
    `lon` - in decimal degrees.
  Returns:
    elevation in meters.

### getElevation

    public int getElevation(float lat,
                            float lon,
                            int level)

  Return the elevation of a lat/lon point, in meters.

  Parameters:
    `lat` - in decimal degrees.
    `lon` - in decimal degrees.
    `level` - the dted level.
  Returns:
    elevation in meters.

### getElevations

    public short[][] getElevations(EqualArc proj,
                                   int dtedLevel)

  Return the two-dimensional matrix of elevation posts (heights) representing coverage of a given geographical rectangle. The matrix represents coverage in an Equal Arc projection, and that's why the rectangle is defined by the projection parameters.

  Parameters:
    `proj` - the projection describing the wanted area
    `dtedLevel` - the DTED level (0, 1, 2) to be used, which describes the geographicsal spacing between the posts.
  Returns:
    array of elevations, in meters. Spacing depends on the DTED level.

### getElevations

    public short[][] getElevations(float ullat,
                                   float ullon,
                                   float lrlat,
                                   float lrlon,
                                   int dtedLevel)

  Return the two-dimensional matrix of elevation posts (heights) representing coverage of a given geographical rectangle. The matrix represents coverage in an Equal Arc projection. Doesn't handle projections which cross the dateline - You must handle that yourself by making two inquiries.

  Parameters:
    `ullat` - upper latitude, in decimal degrees
    `ullon` - left longitude, in decimal degrees
    `lrlat` - lower latitude, in decimal degrees
    `lrlon` - right longitude, in decimal degrees
    `dtedLevel` - the DTED level (0, 1, 2) to be used, which describes the geographicsal spacing between the posts.

### getElevations

    protected short[][] getElevations(float ullat,
                                      float ullon,
                                      float lrlat,
                                      float lrlon,
                                      int dtedLevel,
                                      DTEDFrame refFrame)

  Return the two-dimensional matrix of elevation posts (heights) representing coverage of a given geographical rectangle. The matrix represents coverage in an Equal Arc projection. Doesn't handle projections which cross the dateline - You must handle that yourself by making two inquiries.

  This method is slightly different that the one above, because it includes a input variable DTEDFrame. There is an inherent problem in the algorithm if some of the DTED frames are missing. It's too difficult to calculate the size of the return array if you don't know that any frames are available. So, you should always use the method above, which calls this method with a null refFrame. If some of the DTED frames are missing, then this method is called recursively, with a frame to use for calculating post spacings at the right time.

  Parameters:
    `ullat` - upper latitude, in decimal degrees
    `ullon` - left longitude, in decimal degrees
    `lrlat` - lower latitude, in decimal degrees
    `lrlon` - right longitude, in decimal degrees
    `dtedLevel` - the DTED level (0, 1, 2) to be used, which describes the geographicsal spacing between the posts.
    `refFrame` - DTEDFrame used to calculate measurements.
  Returns:
    array of elevations, in meters. Spacing depends on the DTED level.

### setPropertyPrefix

    public void setPropertyPrefix(java.lang.String prefix)

  PropertyConsumer method.

  Specified by:
    `setPropertyPrefix` in interface `PropertyConsumer`
  Parameters:
    `prefix` - the prefix String.

### getPropertyPrefix

    public java.lang.String getPropertyPrefix()

  PropertyConsumer method.

  Specified by:
    `getPropertyPrefix` in interface `PropertyConsumer`
  Returns:
    the prefix string

### setProperties

    public void setProperties(java.util.Properties props)

  PropertyConsumer method.

  Specified by:
    `setProperties` in interface `PropertyConsumer`
  Parameters:
    `props` - a properties object that the PropertyConsumer can use to retrieve expected properties it can use for configuration.

### setProperties

    public void setProperties(java.lang.String prefix,
                              java.util.Properties props)

  PropertyConsumer method.

  Specified by:
    `setProperties` in interface `PropertyConsumer`
  Parameters:
    `prefix` - a String used by the PropertyConsumer to prepend to each property value it wants to look up - setList.getProperty(prefix.propertyKey). If the prefix had already been set, then the prefix passed in should replace that previous value.
    `props` - a Properties object that the PropertyConsumer can use to retrieve expected properties it can use for configuration.

### getProperties

    public java.util.Properties getProperties(java.util.Properties props)

  PropertyConsumer method.

  Specified by:
    `getProperties` in interface `PropertyConsumer`
  Parameters:
    `props` - a Properties object to load the PropertyConsumer properties into. If getList equals null, then a new Properties object should be created.
  Returns:
    Properties object containing PropertyConsumer property values. If getList was not null, this should equal getList. Otherwise, it should be the Properties object created by the PropertyConsumer.

### getPropertyInfo

    public java.util.Properties getPropertyInfo(java.util.Properties props)

  PropertyConsumer method.

  Specified by:
    `getPropertyInfo` in interface `PropertyConsumer`
  Parameters:
    `props` - a Properties object to load the PropertyConsumer properties into. If getList equals null, then a new Properties object should be created.
  Returns:
    Properties object containing PropertyConsumer property values. If getList was not null, this should equal getList. Otherwise, it should be the Properties object created by the PropertyConsumer.

### main

    public static void main(java.lang.String[] args)

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