Astronomy image mosaic

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Astronomy image mosaic

• R.I.T
• Bo Mu

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Project Goals

• Mosaic 2MASS images and Chandra X-ray images
• Visualize the overlay result
• Reposition and register display images relative
  to reference points

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Background

• 2MASS
• 2 Micron All Sky survey.
• High resolution infrared Image.
• Potential to detect members nearby(dlt2kpc)
  cluster.
• color is helpful to distinguish stars

FOR MORE INFO...
pegasus.phast.umass.edu/ A parsec is the
distance at which a star has a parallax of 1
arcsec.
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Background

• Chandra X-ray image
• 1. Represent powerful
• - Young,low-mass star are highly luminous
  and variable X-ray source
• 2. Overcome the ambiguities in crowed regions
  near the galactic plane.

FOR MORE INFO...
http//www.chandra.harvard.edu/
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Trade Off

• 2mass,CXO
• High resolution(0.1), Low sensitivity
• Optical Image
• Low resolution(5), High sensitivity
• Need to Combine with 2mass, CXO and
  XMM/Newton(optical) image

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Example

• NGC2362

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Challenge

• Easy?
• Coordination known.
• No!
• Coordination has limited accuracy
• Multi-resolution
• Background differs significantly
• Bad Pixel effect

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Solution

• Refine coordination system by reference point
• Multi-resolution Algorithm (wavelet?)
• Back ground equalization
• Subtract the dark image.

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Expectation

• Visualization
• Contrast adjust interactively
• Zoom
• Some filters to help investigate image.

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Current Status

• Astronomy image file format
• fits file
• keyword (naxis,crpix,crval,crot,cdelta) in header
  
• Process Structure array to save multi image data.

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Current Status

• Algorithm
• Read into multi astro images with fits format
• Calculate max,min border
• Adjust the order of images according to the
  coordinates(RA,DEC)
• Data Structure

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Data relation
B
B
A
A
C
C
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Current Status

• Algorithm
• Multi-resolution. Use shift function to solve it.
  More complex, try wavelet Algorithm.
• Try Crosscorrealtion
• Calculate the gray level(Average back ground or
  histogram. Value 1,0, 650-800,gt10000)
• Geometric correction(option)
• Redefine the data structure
• Write into a new fits file

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GUI

• Read multifiles into a structure by
  gtgtDialog_Pickfile(,/multiple)
• gtgtReadfits
• Initialize interface
• Dynamic distribute display window according
  to the number of images
• Display images with mouse position and astronomy
  coordinates.

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GUI

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GUI

• GUI menu, label, text,slider
• display window,dialog
• Slider to adjust image contrast
• Solve the trouble on displaying multiimages and
  capture mouse focus among subwindows.
• Working on zooming image

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GUI

• Plan to design file select dialog

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• Thanks!