ucar.unidata.data.radar

Class Level2Data

java.lang.Object

ucar.unidata.data.radar.Level2Data

public class Level2Data
extends java.lang.Object

This class reads a NEXRAD level II data file and keeps track of cut start and other info. Will probably change in the future.

Adapted with permission from the Java Iras software developed by David Priegnitz at NSSL.

Documentation on Archive Level II data format can be found at: http://www.ncdc.noaa.gov/oa/radar/leveliidoc.html

Version:

$Revision: 1.27 $ $Date: 2007/05/04 16:00:18 $

Author:

MetApps Development Team

Field Summary

Fields

Modifier and Type	Field and Description
static java.lang.String	AR2V0001 Identifier for AR2V0001 format
static java.lang.String	ARCHIVE2 Identifier for ARCHIVE2 format

Constructor Summary

Constructors

Constructor and Description
Level2Data(java.io.File file, DataContext context) Create a new Level II data wrapper for the file
Level2Data(java.lang.String filename, DataContext context) Create a new Level II data wrapper for the file

Method Summary

Modifier and Type	Method and Description
float	getAzimuth(int record) This method returns the azimuth angle for the specified record.
float	getCutElevation(int i) Get the elevation angle of a particular cut
int	getCutIndex(int i) Get the index of the particular cut
int	getCutStart(int cut_num) This method returns the record number where the specified elevation cut begins.
ucar.netcdf.RandomAccessFile	getDataInput() Get the DataInput for this this data
java.lang.String	getDataType() Get the data type (ARCHIVE2, AR2V0001) for this file.
float	getElevation(int record) This method returns the elevation angle for the specified record.
java.lang.String	getFilename() Get the filename that this is using for input
int	getJulianDate() Get the starting Julian date for this volume
int	getNumberOfCuts() Get the number of cuts found in this file.
int	getNumberOfTrueCuts() Get the true number of slices from the file.
int	getSecsSinceMidnight() Get the starting time in seconds since midnight.
java.lang.String	getStationId() Get the station ID for this data
float	getTrueElevation(int i) Get the true elevation for a particular cut
int	getVCP() Get the Volume Coverage Pattern number for this data.
static void	main(java.lang.String[] args) Test the class.
int	numberOfRecords() This method returns the number of records read in from a file.
void	read(int startFlag) Method to read the file.
void	read(int startFlag, boolean onlyVCP) Method to read the file.

Methods inherited from class java.lang.Object

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

Field Detail

ARCHIVE2

public static final java.lang.String ARCHIVE2

Identifier for ARCHIVE2 format

See Also:

Constant Field Values

AR2V0001

public static final java.lang.String AR2V0001

Identifier for AR2V0001 format

See Also:

Constant Field Values

Constructor Detail

Level2Data

public Level2Data(java.io.File file,
                  DataContext context)
           throws java.io.IOException

Create a new Level II data wrapper for the file

Parameters:

file - file to read

context - DataContext for finding temporary directory

Throws:

java.io.IOException - problem reading or writing file

Level2Data

public Level2Data(java.lang.String filename,
                  DataContext context)
           throws java.io.IOException

Create a new Level II data wrapper for the file

Parameters:

filename - name of the file to read

context - DataContext for finding temporary directory

Throws:

java.io.IOException - problem reading or writing file

Method Detail

read

public void read(int startFlag)

Method to read the file.

Parameters:

startFlag - starting record number (unused)

read

public void read(int startFlag,
                 boolean onlyVCP)

Method to read the file. If * onlyVCP, only read enough data to get the levels.

Parameters:

startFlag - starting record number (unused)

onlyVCP - if true, only read until we get the VCP info

getNumberOfTrueCuts

public int getNumberOfTrueCuts()

Get the true number of slices from the file. May differ from expected cuts.

Returns:

number of true cuts

getCutIndex

public int getCutIndex(int i)

Get the index of the particular cut

Parameters:

i - cut number

Returns:

cut index

getNumberOfCuts

public int getNumberOfCuts()

Get the number of cuts found in this file.

Returns:

the number of cuts

getCutElevation

public float getCutElevation(int i)

Get the elevation angle of a particular cut

Parameters:

i - cut number

Returns:

elevation angle

getTrueElevation

public float getTrueElevation(int i)

Get the true elevation for a particular cut

Parameters:

i - cut number

Returns:

true elevation angle (may differ from published values)

getCutStart

public int getCutStart(int cut_num)

This method returns the record number where the specified elevation cut begins.

Parameters:

cut_num - cut number

Returns:

starting record number for that cut.

getAzimuth

public float getAzimuth(int record)

This method returns the azimuth angle for the specified record.

Parameters:

record - record number

Returns:

azimuth angle for the specified record.

getElevation

public float getElevation(int record)

This method returns the elevation angle for the specified record.

Parameters:

record - record number

Returns:

elevation angle for the specified record.

numberOfRecords

public int numberOfRecords()

This method returns the number of records read in from a file.

Returns:

number of data records read in this file.

getVCP

public int getVCP()

Get the Volume Coverage Pattern number for this data.

Returns:

VCP with:

 Value of:    11 = 14 elev. scans/ 5 mins.
              12 = 14 elev. scans/ 4.1 mins.
              21 = 11 elev. scans/ 6 mins.
              31 = 8 elev. scans/ 10 mins.
              32 = 7 elev. scans/ 10 mins.
             121 = 9 elev. scans/ 5 mins.
 

getJulianDate

public int getJulianDate()

Get the starting Julian date for this volume

Returns:

Modified Julian date referenced from 1/1/70.

getSecsSinceMidnight

public int getSecsSinceMidnight()

Get the starting time in seconds since midnight.

Returns:

Generation time of data in milliseconds of day past midnight (UTC).

getDataInput

public ucar.netcdf.RandomAccessFile getDataInput()

Get the DataInput for this this data

Returns:

the DataInput

getStationId

public java.lang.String getStationId()

Get the station ID for this data

Returns:

station ID (may be null)

getDataType

public java.lang.String getDataType()

Get the data type (ARCHIVE2, AR2V0001) for this file.

Returns:

data type

getFilename

public java.lang.String getFilename()

Get the filename that this is using for input

Returns:

filename

main

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

Test the class.

Parameters:

args - file to read

Throws:

java.io.IOException - problem reading file