Instructions to generate fits:

Typical header with required keywords/values:

SIMPLE = T /

BITPIX = -32 /IEEE real 4. Other values: 16, 32, 64, -64 /for 16, 32, 64: use BSCALE and BZERO keys.

NAXIS = 3 /datacube

NAXIS1 = 512 /size 1st axis. Possible values: 512, 1024, 2048

NAXIS2 = 512 /size 2nd axis, see above

H & K band: resolution ~100, N band (8.7-13.1mic) band: R~30. The 3rd axis is the spectral axis. 20 spectral elements are reasonable:

NAXIS3 = 20 /size 3rd (spectral) axis. 20 spectral elements , Values of the two spatial axis:

Pixels scale is 0.1 millisec for H and K images/cubes, 1mas /pixel for N band

CRVAL1 = 0 / center is at 0 offset on sky (Right Ascension)

CRPIX1 = 256 / reference pixel would be pixel 256 if NAXIS1=512

CDELT1 = -0.4848136811095E-10 / increment between pixels is is 0.1 millisec (IN RADIANS: MANDATORY),and is 'astronomy oriented (negative)'

CRVAL2 = 0 / center is at 0 DEC offset on sky

CRPIX2 = 256 / reference pixel is 256 in Delta

CDELT2 = 0.4848136811095E-10 / increment is 0.1 millisec.

values for the spectral axis:

CTYPE3 = 'WAVELENGTH' / MANDATORY: means that Cxxxx3 are in Microns

CRPIX3 = 1 / reference pixel(channel) is 1 on 3rd axis

CRVAL3 = 2.2 / 2.2 microns for this pix/channel

CDELT3 = 0.02 / microns channel width

Other mandatory keywords

MAGV = 3.3 / magnitude V of star ( for AO)

MAGK = 6.6 /K mag for FT MAGH = 4.4 /H mag for FT

TOTFLUX = 2.5434E12 /Total flux in the image or cube.

The image's values can be in any unit. More keywords are recomended that can give a better view of what is inside the fits file:

OBJECT = 'HD 86554' / name (for bookeeping)

RA = 0.6800000000000E+02 / Right Ascension RADIANS (for bookeeping)

DEC = 0.2600000000000E+02 / Declination RADIANS (for bookeeping)

EPOCH = 2008 / Epoch (for bookeeping)

EQUINOX = 2008 / Equinox (for bookeeping)

ORIGIN = 'MY Simulator' /

DATE-OBS= '2005-12-02T00:00:00.00' / Date image/cube produced.

Interferometers configuration:

This first table contains the proposed configurations. The spectral resolution is here to improve the (u,v) coverage. For CHARA I am waiting for John's response.

Config # Interferometer Number of telescopes Time for one calibrate point Spectral resolution Filter
1 Gravity/Matisse/VSI 4 T 40 mn 18 spectral channels (13 in N) H,K,N
2 VSI 6 T 40 mn 18 spectral channels H,K
3 MROI 6 T (3x4) 20 mn 18 spectral channels H,K
4 CHARA 6 T    

Information on images:

Topic Author Band Info/comment Oifits Generated (Y,N) Image reconstruction
AGN S. Hoenig   No inclination, low contrast except N, asked for more
    H Config 1(4T VLTI) No No
    K Config 2(6T VLTI) No No
    N Config 3(6T MROI) No No
Planet in disk H. Jang-Condell   Low contrast, asked for images with gaps  
    H Config 1(4T VLTI) No No
    K Config 2(6T VLTI) No No
    N Config 3(6T MROI) No No
Supergiant A. Chiavassa Convection cells
    H Config 1(4T VLTI) No No
    K Config 2(6T VLTI) No No
    N Config 3(6T MROI) No No
Evolved star T. Verhoelst Low contrast envelop shells, circular symmetry, asked for more No No
    H Config 1(4T VLTI) No No
    K Config 2(6T VLTI) No No
    N Config 3(6T MROI) No No

-- JeanPhilippeBerger - 29 Apr 2009

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Topic revision: r2 - 2009-05-06 - JeanPhilippeBerger
 
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