astrometry+sextractor SIP distorsion paramenter problem.

[Nacho Mas]

Hello everyone!

I am Nacho Mas from  http://www.lasagraskysurvey.es/  NEO hunter project. I am using astrometry.net software for solving flawlessly about 2000 fits per day (Great!!).

My workflow include astrometry.net+sextractor+pyraf and I found a problem because I sextractor and iraf  don't understand the SIP distorsion parameters that astrometry.net produce. Dustin told me that there is a  wcs-pv2sip converter in the astrometry.net suite  but not the other way around. Also mention and other executable ' wcs-xy2rd' that solved part of my problem (the pyraf part).

I would like to share my solution for if usefull to others: Surfing the web I found this paper from PTF (Palomar Transient Factory) http://web.ipac.caltech.edu/staff/shupe/reprints/SIP_to_PV_SPIE2012.pdf and asked them about the availability of the "sip2pv" soft. They told me that they are trying to release the code under GPL licensing (Caltech burocracy) but meanwhile they send me the Ubuntu statically linked executable.

I asked them for permision to share this solution with the comunity and gently grand me permision and send me both executables sip2pv and pv2sip (THANKS RUSS!).  Is there any place in the forum to put this exe accesible to every one?

Regards

Nacho Mas

[Dustin Lang]

Nice work.

Can you upload the exe as a file attachment?

If it's too big for that, email it to me and I can put it up at data.astrometry.net

cheers,
--dustin

[Dustin Lang]

Thanks -- these are available at:
http://data.astrometry.net/pv2sip-binaries-intel/

[Nacho Mas]

Some additional information:

They was build on a 64-bit Intel-CPU-based machine running RHE 6 Linux and  statically linked to the libm and libcfitsio libraries. I use in a Ubuntu 12.04 without problems

Please be aware the software is coded specifically to handle 4th-order-polynomial distortion used at Palomar Transient Factory, so you have to use  "--tweak-order 4"  flag in solve-field  to work properly.

$ sip2pv

sip2pv, v. 1.1

Usage:

-i <input image file>

-o <output image file>

[-v (verbose switch)]

Regards