astro
Class SpectralFits

java.lang.Object
  nom.tam.fits.Fits
      astro.SpectralFits

Direct Known Subclasses:

SesFits

public abstract class SpectralFits
extends nom.tam.fits.Fits

This class deals with FITS file received as output from the SES spectrograph. This is a three dimensional fits file, where the x-coordinate (first axis) is along the echell order, 2043 pixel, the second axis is the order number, 82, and the third one indicates the image. In index zero, the reduced spectrum is found, in index 1 the raw extracted spectrum and in index 2 a sigma map of the pixel. The data typoe is float.

Field Summary

private File	fits The original file where the ses fits is stored.
private double	ltm Convert image pixel to physical pixels used for further processing.
private static String	LTM Header keyword for apertures.
private double	ltv Convert image pixel to physical pixels used for further processing.
private static String	LTV Header keyword for apertures.
private float[][]	raw After construction, we have these arrays available.
private float[][]	reduced After construction, we have these arrays available.
private float[][]	sigma After construction, we have these arrays available.
private Function[]	wavelength The wavelength solution for the orders, parsed from the header.

Constructor Summary

protected

SpectralFits(File io) Constructs a SesFits from a file.

Method Summary

int	getCentralOrderFromAngstrom(double lambda) Return the orders where the specified wavelength fits best or -1 if no such order is available.
int	getHighestOrder() Returns the array size, -1 if undefined.
int	getIndexOfOrder(int order) Default implementation says aperture number equals order number.
int	getLowestOrder() Default implementation return 0 for lowest order number, -1 if undefined.
int	getOrderOfIndex(int index) Default implementation says aperture number equals order number.
int[]	getOrdersFromAngstrom(double lambda) Return all orders where the specified wavelength can be found.
Vector3D[]	getRawOrder(int order) Returns the specified order as an array of wavelength vs.
Vector3D[]	getReducedOrder(int order) Returns the specified order as an array of wavelength vs.
protected abstract Function[]	parseWavelengthSolution(nom.tam.fits.Header h) Parses the wavelength soultion from the header.

Methods inherited from class nom.tam.fits.Fits

addHDU, currentSize, deleteHDU, fileInit, getHDU, getNumberOfHDUs, getStream, insertHDU, makeHDU, makeHDU, makeHDU, randomInit, read, read, readHDU, setChecksum, setChecksum, setStream, size, skipHDU, skipHDU, streamInit, streamInit, streamInit, version, write

Methods inherited from class java.lang.Object

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

Field Detail

LTV

private static final String LTV

Header keyword for apertures.

See Also:

Constant Field Values

LTM

private static final String LTM

Header keyword for apertures.

See Also:

Constant Field Values

fits

private File fits

The original file where the ses fits is stored.

ltv

private double ltv

Convert image pixel to physical pixels used for further processing.

ltm

private double ltm

Convert image pixel to physical pixels used for further processing.

reduced

private float[][] reduced

After construction, we have these arrays available.

raw

private float[][] raw

After construction, we have these arrays available.

sigma

private float[][] sigma

After construction, we have these arrays available.

wavelength

private Function[] wavelength

The wavelength solution for the orders, parsed from the header.

Constructor Detail

SpectralFits

protected SpectralFits(File io)
                throws nom.tam.fits.FitsException

Constructs a SesFits from a file. Note this throws FitsException if file was not found or data could not be read due to I/O. The fits is expected to be composed of a three-dimensional float array

Throws:

nom.tam.fits.FitsException

Method Detail

getIndexOfOrder

public int getIndexOfOrder(int order)

Default implementation says aperture number equals order number.

getOrderOfIndex

public int getOrderOfIndex(int index)

Default implementation says aperture number equals order number.

getLowestOrder

public int getLowestOrder()

Default implementation return 0 for lowest order number, -1 if undefined.

getHighestOrder

public int getHighestOrder()

Returns the array size, -1 if undefined.

getCentralOrderFromAngstrom

public int getCentralOrderFromAngstrom(double lambda)

Return the orders where the specified wavelength fits best or -1 if no such order is available.

Parameters:

lambda - The wavelength in Angstrom.

Returns:

The best order number

getOrdersFromAngstrom

public int[] getOrdersFromAngstrom(double lambda)

Return all orders where the specified wavelength can be found.

Parameters:

lambda - The wavelength in Angstrom.

Returns:

Either zero length, a single-element int or a bi-element int for overlapping regions

getReducedOrder

public Vector3D[] getReducedOrder(int order)
                           throws nom.tam.fits.FitsException

Returns the specified order as an array of wavelength vs. intensity plus error. Note that the image pixel number in dispersion direction (1...NAXIS1) is first converted to physical coordinates using the LTV1 and LTM1_1 keywords. This physical coordinate (in most cases identical to the image pixel number) is then used in the wavelength solution to get to lambda, normally in Angstrom.

Throws:

nom.tam.fits.FitsException - If the requested order cannot be reached

getRawOrder

public Vector3D[] getRawOrder(int order)

Returns the specified order as an array of wavelength vs. intensity plus error. Note that the image pixel number in dispersion direction (1...NAXIS1) is first converted to physical coordinates using the LTV1 and LTM1_1 keywords. This physical coordinate (in most cases identical to the image pixel number) is then used in the wavelength solution to get to lambda, normally in Angstrom.

parseWavelengthSolution

protected abstract Function[] parseWavelengthSolution(nom.tam.fits.Header h)
                                               throws nom.tam.fits.FitsException

Parses the wavelength soultion from the header.

Throws:

nom.tam.fits.FitsException