Testing Guide Mode: AUTO

The DECam guiding has been shown to work if you select your guide stars.  However, the guide software has been written with something more sophisticated in mind--it will select guide stars automatically, with no interaction from the observer. 

Tonight we started testing this "auto" mode.  We first loaded the "starfinder" software in a focus and alignment  (F&A) CCD to see where the starfinder stars are.  This screenshot (courtesy Aaron R.) shows the results.  The red circles designate the starfinder stars, and the donuts are the stars in an F&A CCD. The difference between the starfinder stars and a star in a F&A CCD is approximately 20 arcseconds. 

 We then started the guide software in auto mode and with a region of interest 100 x 100 pixels.  There were no stars in the guide CCDs.  We then started increased the region of interest to 300 x 300 pixels, and guide stars were seen in all four guide CCDs!  *success*  this screenshot (courtesy Ann E.) shows the four stars.

The TSCINTERFACE seemed to be sending offset/guiding commands to the telescope control system (TCS)--we could see these offset commands appear in the TCSINTERFACE console.  However, we do not know if these actually reached the TCS.  We have our doubts--this is because the RA centroid and DEC centroid did not converge about ~0 arcsec (see bottom right hand corner).  Instead, as clearly seen, the centroids are getting worse with time.

Then the clouds rolled in, and the humidity spiked.  We closed.  We'll be doing more guider tests tomorrow night, weather permitting.  We need to understand (1.) how to make the starfinder stars match closer to a star in a Guide CCD and (2.) why the RA and DEC centroid values are not converging around zero.