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On 3 July 2014 16:19, Jean-Baptiste Marquette <[log in to unmask]> wrote: > Hi Tim, > >> It's crashing in astGetCurrent. I just tried it on a random image and >> "Tweak existing calibration" worked fine for me and I saved the new file. >> This was an NDF. >> >> It may be that we will need your actual file and actual tweaks to proceed >> further. >> >> >> Follow this link: >> >> >> https://dl.dropboxusercontent.com/u/2021308/VCAM.2010-08-15T03%3A58%3A27.513.chip5.fits >> > > I assume that Peter is right and that your problem is fixed in the > development version and will make it out in the 2014A release (imminently). > > > Great! > > >> >> This is an image from VISTA Paranal, extracted from ESO archive, and with >> some modified keywords towards the standard TAN projection instead of the >> ZPN original one. Indeed, it is claimed on this CASU page: >> >> http://casu.ast.cam.ac.uk/surveys-projects/vista/data-processing >> >> that « ZPN is instead correctly understood by other software packages like >> DS9 and Gaia. » But a match with 2MASS evidently fails on both, using the >> ZPN version of the header… >> > > I don't understand why ZPN vs TAN matters when matching with 2MASS. What is > the actual 2MASS problem? Is it GAIA auto astrometry that is failing with > 2MASS+ZPN? That shouldn't matter as SExtractor should understand it. > > > This screenshot shows a zoom on the original ZPN image with 2MASS over > plotted. The arrows show the systematic shift between the actual sources and > their 2MASS counterparts. Considering that this image is from the ESO > archive, that shift is totally unexpected, since the astrometry is supposed > to be properly described by the ZPN keywords. The TAN version is a tentative > to overcome this issue. It shows a quite analog shift when displayed in > Gaia. If this ZPN problem affects both gaia and ds9 then I suppose AST is an obvious suspect (or the headers themselves I suppose). Could you let me have a copy of the file with the original ZPN headers? David ---- Starlink User Support list For list configuration, including subscribing to and unsubscribing from the list, see https://www.jiscmail.ac.uk/cgi-bin/webadmin?A0=STARLINK