View on GitHub

IRAF Community Distribution

IRAF maintained by the community

Home | Installation | Packages | X11IRAF | PyRAF | Forum

How to install tfinder?

ping zhao wrote on Jul 11, 2011

Hello,

I have CCD images from CTIO Yalo-1m telescope. They only have telescope pointing but no astrometry solution for the image itself. Can tfinder make the astrometry solution for the images? If so, where do I get the tfinder?

Thanks,

Ping

Francisco Valdes wrote on Jul 11, 2011

I'm not sure about the availability of tfinder. However, there is a somewhat easier to use task called msctpeak which derived from tfinder. This task is in the mscfinder package of either mscred or nfextern.msctools. Both of these package are readily available for current versions of IRAF. With V2.15 you can use the simplified dynamic installation option (see extern$README). For earlier versions of IRAF you find things at the ftp:/iraf.noao.edu site or iraf.net.

You might find the link:

http://iraf.noao.edu/projects/ccdmosaic/astrometry/astrom.html

while the msc packages and tasks and this link talk about multi-extension files like mosaic cameras, everything works with single images as well.

Frank Valdes

ping zhao wrote on Jul 11, 2011

Hi Frank,

Thank you for your reply.

I think in order for msctpeak to work. The image itself should have at least some sort of WCS, even it's off. But the images from yalo1m has no WCS at all. If you display it with ds9, the WCS block is blank. The image header does have telescope pointing:

RA = '16:54:16.70' / Telescope RA at EQUINOX
DEC = '-39:52:29.1' / Telescope DEC at EQUINOX

Is there something I can add to the header to make WCS appear in the image?

Thanks!

Ping

Francisco Valdes wrote on Jul 11, 2011

Hi Ping,

Check out the task "mkcwcs". You have the ra and dec already. You need to figure out the scale and the orientaion on the sky. In case it isn't clear, the rapix and decpix specify a point in the image to which the ra and dec apply.

Frank

ping zhao wrote on Jul 11, 2011

Hi Frank,

Thank you for your very quick reply.

I just tried "mkcwcs". It works!

Thank you very much!

Best,
Ping

Last post on Jul 11, 2011